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Rudszuck T, Nirschl H, Guthausen G. Combined nuclear magnetic resonance methods in quality control of lubricants in green energy production. Magn Reson Chem 2024; 62:212-221. [PMID: 36843335 DOI: 10.1002/mrc.5339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/17/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
NMR methods were applied for lubricant analysis. Different factors influence the real aging of lubricants on diverse length scales and are captured by NMR. Chemical conversion of additives is addressed by NMR spectroscopy. High-field NMR experiments allow the identification and quantification of chemical components and are transferred to benchtop devices. Molecular dynamics and contaminations like fuel or abrasion are addressed via NMR relaxation and diffusion. Quality parameters were extracted via suitable data analysis of NMR raw data, which allow the detection of aging and indicate changes in the oil composition. At the same time, the methodology is optimized to the conditions in quality control. The feasibility is shown the example of a series of lubricants from applications in regenerative energy production, namely, wind turbine oils and biogas motor oils.
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Affiliation(s)
- Thomas Rudszuck
- Institute for Mechanical Engineering and Mechanics, KIT, 76131, Karlsruhe, Germany
| | - Hermann Nirschl
- Institute for Mechanical Engineering and Mechanics, KIT, 76131, Karlsruhe, Germany
| | - Gisela Guthausen
- Institute for Mechanical Engineering and Mechanics, KIT, 76131, Karlsruhe, Germany
- Engler-Bunte Institut, Water Chemistry and Technology, KIT, 76131, Karlsruhe, Germany
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2
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Drabik J, Korasiak K, Chrobak J, Woch J, Brzeźniak N, Barszcz W, Kozdrach R, Iłowska J. Amide/Amino-Based Functional Additives for Lubricants: Structure, Antimicrobial Activity and Wear Resistance. Molecules 2023; 29:122. [PMID: 38202705 PMCID: PMC10780008 DOI: 10.3390/molecules29010122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
The lubricating properties of the lubricants were tested under boundary friction conditions; it was found that the surface-active additives had reduced the wear mark and thus the value of the Goz/40 parameter (limiting load of wear). The introduction of a surfactant containing amide compounds into the oils and greases was highly effective in slowing down the oxidation process. Lubricants containing mono-15 ([3-(N,N,N-dimethylbuthylamine)propyl]hexadecanamide chloride) and 15-4-15 (tetramethylene-bis [3-(N,N,N-dimethylamine)propyl]hexadecanamide) additives were characterised by higher oxidation stability compared to the unmodified lubricants. Both of the analysed substances showed bactericidal properties against Staphylococcus aureus and Salmonella enteritica. Tests of antibacterial activity in the lubricants with the addition of mono-15 and 15-4-15 confirmed that these lubricants can be considered bactericidal against Gram-positive and Gram-negative bacteria.
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Affiliation(s)
- Jolanta Drabik
- Łukasiewicz Research Network–Institute for Sustainable Technologies, 26-600 Radom, Poland; (J.D.); (W.B.); (R.K.)
| | - Kamil Korasiak
- Łukasiewicz Research Network–Institute of Heavy Organic Synthesis “Blachownia”, 47-225 Kędzierzyn-Koźle, Poland; (K.K.); (J.W.); (N.B.); (J.I.)
| | - Justyna Chrobak
- Łukasiewicz Research Network–Institute of Heavy Organic Synthesis “Blachownia”, 47-225 Kędzierzyn-Koźle, Poland; (K.K.); (J.W.); (N.B.); (J.I.)
| | - Julia Woch
- Łukasiewicz Research Network–Institute of Heavy Organic Synthesis “Blachownia”, 47-225 Kędzierzyn-Koźle, Poland; (K.K.); (J.W.); (N.B.); (J.I.)
| | - Natalia Brzeźniak
- Łukasiewicz Research Network–Institute of Heavy Organic Synthesis “Blachownia”, 47-225 Kędzierzyn-Koźle, Poland; (K.K.); (J.W.); (N.B.); (J.I.)
| | - Wioletta Barszcz
- Łukasiewicz Research Network–Institute for Sustainable Technologies, 26-600 Radom, Poland; (J.D.); (W.B.); (R.K.)
| | - Rafał Kozdrach
- Łukasiewicz Research Network–Institute for Sustainable Technologies, 26-600 Radom, Poland; (J.D.); (W.B.); (R.K.)
| | - Jolanta Iłowska
- Łukasiewicz Research Network–Institute of Heavy Organic Synthesis “Blachownia”, 47-225 Kędzierzyn-Koźle, Poland; (K.K.); (J.W.); (N.B.); (J.I.)
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3
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Goculdas T, Korathotage K, Montone C, Sadula S, Bloch ED, Vlachos DG. Synthesis of Long Chain Oxygenates via Aldol Condensation of Furfural and Acetone over Metal-Organic Frameworks. ACS Appl Mater Interfaces 2023. [PMID: 38047592 DOI: 10.1021/acsami.3c13037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Enormous efforts have been made to convert biomass to liquid fuels and products catalytically. Long molecules with a suitable structure are ideal precursors for fuels and value-added products. Here, a C21 oxygenate was synthesized for the first time in one step through aldol condensation of furfural and acetone over the amine-functionalized zirconium-based metal-organic framework (MOF), UiO-66-NH2. Structural changes of UiO-66-NH2 were investigated to improve the yield and evaluate the role of the ligand, cluster node, defectiveness, modulator, surface area, and textural properties on the product distribution. We demonstrate the possibility of making long-chain oxygenates without using vegetable oil-derived fatty acids toward 100% waste biomass-derived renewable fuels, lubricants, and surfactants.
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Affiliation(s)
- Tejas Goculdas
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy Street, Newark, Delaware 19716, United States
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy Street, Newark, Delaware 19716, United States
| | - Kaushalya Korathotage
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy Street, Newark, Delaware 19716, United States
- Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Christine Montone
- Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Sunitha Sadula
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy Street, Newark, Delaware 19716, United States
| | - Eric D Bloch
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy Street, Newark, Delaware 19716, United States
- Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Dionisios G Vlachos
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy Street, Newark, Delaware 19716, United States
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy Street, Newark, Delaware 19716, United States
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Jopen M, Paulus M, Sternemann C, Degen P, Weberskirch R. Comparative Studies on the Organogel Formation of a Polyester in Three Different Base Oils by X-ray Analysis, Rheology and Infrared Spectroscopy. Gels 2023; 9:696. [PMID: 37754377 PMCID: PMC10530540 DOI: 10.3390/gels9090696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/16/2023] [Accepted: 08/24/2023] [Indexed: 09/28/2023] Open
Abstract
High-performance greases typically consist of a base oil and polyurea as a thickener material. To date, few alternatives to polyureas have been investigated. Polyesters could be one such alternative; however, little is known about the gelation of such polyesters because, unlike polyureas, they cannot form hydrogen bonds between the polymer chains. Here, we present studies on the gel formation of a polyester based thickener poly(hexane dodecanoate) with 1-octanol endgroups in three different base oils, i.e., a mineral oil (Brightstock 150), a synthetic Polyalphaolefin (Spectrasyn 40) and castor oil (85 to 90 wt.% ricinoleic acid triglyceride). Small- and wide-angle X-ray scattering measurements indicate a strong interaction of the polyester with castor oil and an increase in the crystalline fraction, with an increasing polymer amount from 5 to 40 wt.%. Moreover, infrared analysis of the polyester in castor oil showed gel formation at a minimum concentration of 20 wt.%. The strong interaction of the polyester with castor oil compared to the other two base oils led to an increase in the yield point γF as a measure of the mechanical stability of the gel, which was determined to be 5.9% compared to 0.8% and 1.0% in Brightstock and Spectrasyn, respectively.
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Affiliation(s)
- Max Jopen
- Carl Bechem GmbH, Weststraße 120, 58089 Hagen, Germany; (M.J.); (P.D.)
| | - Michael Paulus
- Fakultät Physik/DELTA, Technische Universität Dortmund, 44221 Dortmund, Germany; (M.P.); (C.S.)
| | - Christian Sternemann
- Fakultät Physik/DELTA, Technische Universität Dortmund, 44221 Dortmund, Germany; (M.P.); (C.S.)
| | - Patrick Degen
- Carl Bechem GmbH, Weststraße 120, 58089 Hagen, Germany; (M.J.); (P.D.)
| | - Ralf Weberskirch
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Str. 6, 44227 Dortmund, Germany
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Żaba K, Trzepieciński T. Cold Drawing of AISI 321 Stainless Steel Thin-Walled Seamless Tubes on a Floating Plug. Materials (Basel) 2023; 16:5684. [PMID: 37629975 PMCID: PMC10456630 DOI: 10.3390/ma16165684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023]
Abstract
The paper presents the results of an analysis of the process of drawing AISI 321 stainless steel thin-walled seamless tubes on a floating plug. The influence of the geometry of dies and plugs, drawing velocity, and lubricants on the possibility of carrying out the pipe drawing process without a loss of strength of the lubricating film and, consequently, disturbance of the forming process and tube cracking, and also on the temperature in the drawing process, the mechanical properties of the tubes drawn, and the microhardness and roughness of the inner and outer surface of the tubes was investigated. The parameters of the drawing tools used were as follows: angle of drawing dies α = 16° and floating plugs with angles of inclination of the conical part of the plug β = 11.5°, 13°, and 14°. The drawing dies and floating plugs were made of G10 sintered carbide. Drawing speed was varied over the range 1 to 10 m/min. The study used several lubricants. Tubes with dimensions (outer diameter D0, wall thickness g0 before drawing process) D0 = 19 mm, g0 = 1.2 mm and D0 = 18 mm, g0 = 1.2 mm were drawn to produce tubes with dimensions (outer diameter Dk, wall thickness gk after drawing process) Dk = 16 mm, gk = 1.06 mm on a drawbench with the same total elongation, while the diameter and wall thickness were changed. During the process, continuous measurements were made of the drawing force and temperature in the deformation zone and on the tube surface. It was found that the drawing process causes a decrease in the roughness parameters Ra and Rz of the inner surface of the tubes. Moreover, after drawing, an increase of 30-70% was observed in the microhardness of the tube material in relation to the microhardness of the charge material. Based on the test results, it can be concluded that the work of frictional forces is the main direction of optimization of tube drawing on a floating plug process of hard-deforming materials.
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Affiliation(s)
- Krzysztof Żaba
- Department of Metal Working and Physical Metallurgy of Non-Ferrous Metals, Faculty of Non-Ferrous Metals, AGH—University of Science and Technology, al. Adama Mickiewicza 30, 30-059 Cracow, Poland
| | - Tomasz Trzepieciński
- Department of Manufacturing Processes and Production Engineering, Faculty of Mechanical Engineering and Aeronautics, Rzeszow University of Technology, al. Powst. Warszawy 8, 35-959 Rzeszów, Poland
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Djas M, Matuszewska A, Borowa B, Kowiorski K, Wieczorek P, Małek M, Chlanda A. Flake Graphene as an Innovative Additive to Grease with Improved Tribological Properties. Materials (Basel) 2022; 15:7775. [PMID: 36363365 PMCID: PMC9657073 DOI: 10.3390/ma15217775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
The paper presents the results of research on the use of flake graphene as an additive to plastic grease in order to improve its tribological properties. The influence of concentration (0.25-5.00 wt.%) and the form of graphene (graphene oxide, reduced graphene oxide) on selected properties of the base grease were investigated. It has been found that the addition of graphene flakes improves the anti-wear properties of the lubricant. The greatest improvement in the properties of the lubricant was achieved by using graphene at a concentration of 4.00 wt.%; the reduction in the average diameter of the wear scar was almost 70% for GO and RGO, compared to the base lubricant without the addition of graphene.
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Affiliation(s)
- Małgorzata Djas
- Łukasiewicz Research Network—Institute of Microelectronics and Photonics, al. Lotników 32/46, 02-668 Warsaw, Poland
- Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 02-645 Warsaw, Poland
| | - Anna Matuszewska
- Łukasiewicz Research Network—Automotive Industry Institute, Jagiellońska 55, 03-301 Warsaw, Poland
| | - Beata Borowa
- Łukasiewicz Research Network—Automotive Industry Institute, Jagiellońska 55, 03-301 Warsaw, Poland
| | - Krystian Kowiorski
- Łukasiewicz Research Network—Institute of Microelectronics and Photonics, al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Piotr Wieczorek
- Łukasiewicz Research Network—Automotive Industry Institute, Jagiellońska 55, 03-301 Warsaw, Poland
| | - Marcin Małek
- Faculty of Civil Engineering and Geodesy, Military University of Technology, Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland
| | - Adrian Chlanda
- Łukasiewicz Research Network—Institute of Microelectronics and Photonics, al. Lotników 32/46, 02-668 Warsaw, Poland
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Lin HH, Heinze J, Croy A, Gutiérrez R, Cuniberti G. Effect of lubricants on the rotational transmission between solid-state gears. Beilstein J Nanotechnol 2022; 13:54-62. [PMID: 35059276 PMCID: PMC8744455 DOI: 10.3762/bjnano.13.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Lubricants are widely used in macroscopic mechanical systems to reduce friction and wear. However, on the microscopic scale, it is not clear to what extent lubricants are beneficial. Therefore, in this study, we consider two diamond solid-state gears at the nanoscale immersed in different lubricant molecules and perform classical MD simulations to investigate the rotational transmission of motion. We find that lubricants can help to synchronize the rotational transmission between gears regardless of the molecular species and the center-of-mass distance. Moreover, the influence of the angular velocity of the driving gear is investigated and shown to be related to the bond formation process between gears.
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Affiliation(s)
- Huang-Hsiang Lin
- Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, Dresden, Germany
| | - Jonathan Heinze
- Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, Dresden, Germany
| | - Alexander Croy
- Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, Dresden, Germany
| | - Rafael Gutiérrez
- Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, Dresden, Germany
| | - Gianaurelio Cuniberti
- Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, Dresden, Germany
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González CMO, de Monserrat Navarro Tellez A, Kharisov BI, Hernández JMG, Quezada TES, González LT, de la Fuente IG. Mixed-Metal MOF-Derived Carbon Sponges for Oil Absorption. Recent Pat Nanotechnol 2022; 16:128-138. [PMID: 35297341 DOI: 10.2174/1872210515666210120120331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/26/2020] [Accepted: 11/13/2020] [Indexed: 06/14/2023]
Abstract
AIMS In this work, we propose the implementation of three carbon sponges, generated from the carbonization of melamine-formaldehyde sponges coated with different HKUST-type metal-organic frameworks (MOFs) in different thermal conditions. BACKGROUND Nowadays, numerous investigations are focused on the development of new technologies for the rapid separation of water/oil mixtures. Several of these processes use hydrophobic materials of different nature for efficient oil capture. Despite these efforts, the water/oil separation still remains a great challenge. The main oil absorbers that are commercially available tend to be expensive and have complex synthesis; however, they usually have an acceptable cost/benefit ratio. Despite this, the passage of time has brought us new generations of materials, which seek to solve the problems in a more efficient way, as in the case of metal-organic frameworks (MOFs), which stand out for the great ease with which their morphological and surface aspects can be controlled. MOFs are extensively investigated in the fields of adsorption and catalysis; the MOF coated sponges do not meet the selectivity and stability standards to be applied in oil spills in water. However, this completely changes when subjected to the pyrolysis process, giving the material an increase in its surface area, hydrophobic and magnetic properties in addition to making the material suitable for its application. OBJECTIVE Creation of a low-cost 3D template and the study of morphological properties of MOFs, for the formation of carbon-based materials by a fast, simple and low-cost method, promoting the use of new generations of materials to more effectively solve persistent environments. METHODS The employed MOF precursors were trimesic acid (BTC), nickel and cobalt salts. The monometallic HKUST type MOFs were synthesized using a simple method of controlled precipitation, which starts from two precursor solutions. The first one consisted of a ligand solution, dissolving the BTC in deionized water. In the case of mixed-metal MOFs, they were synthesized using the same procedure described for monometallic MOFs, but in this case, a mixture of metal salts with a 1:1 molar ratio was performed. The methodology for the production of the sponges decorated with MOF was carried out in two steps. In the first stage, the sponges were subjected to a wash to remove dust and impurities, being rinsed with acetone in an ultrasonic bath for 30 min. The sponges were subsequently immersed in deionized water and subjected to an ultrasonic bath for 10 min. Finally, the sponges were dried at 60°C for 3 h. The second step was the addition of the HKUST-type MOFs to the sponges was carried out by means of the immersion method, preparing a dispersion of the corresponding MOFs in ethanol. RESULTS It was revealed that the carbon sponges can selectively absorb oil in the water/oil mixture, possessing magnetic and enhanced hydrophobic and superhydrophobic properties. All the pyrolyzed carbon sponges, obtained at 500 and 700°C, were not the most optimal since they had absorption capacities of around 25 g/g and only supported up to 4 absorption cycles. On the other hand, the carbon sponges, obtained at 300°C, had absorption capacities greater than 40 g/g, in addition to being able to be reused up to 12 times without showing significant changes in their absorption capacity and having acceptable hydrophobic characteristics for the removal of oil dispersed in water. Among the three sponges obtained at 300°C, we highlight the sponges coated with BTC-Co, which have the highest absorption capacity (54 g/g) among all fabricated sponges. CONCLUSIONS The sponges obtained in the present work are a promising alternative to the materials that are traditionally used since they have great advantages such as their simple production method, low-cost starting materials and good absorption capacities. This work sheds light on the production of carbon materials from 3D templates decorated with MOFs, through a one-step carbonization process and we demonstrate that these materials have characteristics that make them applicable in the removal of oil dispersed in water, giving us a practical, economic and friendly alternative to the environment.
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Affiliation(s)
- Cesar M Oliva González
- Universidad Autónoma de Nuevo León, Ave. Universidad s/n, San Nicolás de los Garza, N.L., C.P. 66455, México
| | | | - Boris I Kharisov
- Universidad Autónoma de Nuevo León, Ave. Universidad s/n, San Nicolás de los Garza, N.L., C.P. 66455, México
| | | | - Thelma E Serrano Quezada
- Universidad Autónoma de Nuevo León, Ave. Universidad s/n, San Nicolás de los Garza, N.L., C.P. 66455, México
| | - Lucy T González
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Ave. Eugenio Garza Sada 2501, C.P. 64890 Monterrey, N.L., Mexico
| | - Idalia Gómez de la Fuente
- Universidad Autónoma de Nuevo León, Ave. Universidad s/n, San Nicolás de los Garza, N.L., C.P. 66455, México
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Hackler RA, Vyavhare K, Kennedy RM, Celik G, Kanbur U, Griffin PJ, Sadow AD, Zang G, Elgowainy A, Sun P, Poeppelmeier KR, Erdemir A, Delferro M. Synthetic Lubricants Derived from Plastic Waste and their Tribological Performance. ChemSusChem 2021; 14:4181-4189. [PMID: 34038620 DOI: 10.1002/cssc.202100912] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/22/2021] [Indexed: 06/12/2023]
Abstract
The energy efficiency, mechanical durability, and environmental compatibility of all moving machine components rely heavily on advanced lubricants for smooth and safe operation. Herein an alternative family of high-quality liquid (HQL) lubricants was derived by the catalytic conversion of pre- and post-consumer polyolefin waste. The plastic-derived lubricants performed comparably to synthetic base oils such as polyalphaolefins (PAOs), both with a wear scar volume (WSV) of 7.5×10-5 mm-3 . HQLs also performed superior to petroleum-based lubricants such as Group III mineral oil with a WSV of 1.7×10-4 mm-3 , showcasing a 44 % reduction in wear. Furthermore, a synergistic reduction in friction and wear was observed when combining the upcycled plastic lubricant with synthetic oils. Life cycle and techno-economic analyses also showed this process to be energetically efficient and economically feasible. This novel technology offers a cost-effective opportunity to reduce the harmful environmental impact of plastic waste on our planet and to save energy through reduction of friction and wear-related degradations in transportation applications akin to synthetic oils.
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Affiliation(s)
- Ryan A Hackler
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Kimaya Vyavhare
- Applied Materials Division, Argonne National Laboratory, Lemont, IL 60439, USA
- Materials Science and Engineering Department, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Robert M Kennedy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Gokhan Celik
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
- Department of Chemical Engineering, Middle East Technical University, Ankara, 06800, Turkey
| | - Uddhav Kanbur
- Department of Chemistry, Iowa State University and Ames Laboratory, Ames, IA 50011, USA
| | - Philip J Griffin
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Aaron D Sadow
- Department of Chemistry, Iowa State University and Ames Laboratory, Ames, IA 50011, USA
| | - Guiyan Zang
- Systems Assessment Center, Energy Systems Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Amgad Elgowainy
- Systems Assessment Center, Energy Systems Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Pingping Sun
- Systems Assessment Center, Energy Systems Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | | | - Ali Erdemir
- J. Mike Walker'66 Department of Mechanical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Massimiliano Delferro
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
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Miethke L, Prziwara P, Finke JH, Breitung-Faes S. Opposing Effects of Additives in Dry Milling and Tableting of Organic Particles. Pharmaceutics 2021; 13:pharmaceutics13091434. [PMID: 34575509 PMCID: PMC8467332 DOI: 10.3390/pharmaceutics13091434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022] Open
Abstract
Applying additives and excipients during the dry processing of fine particles is a common measure to control the particle–particle interactions, to specifically influence the powder properties and to enhance the process efficiency or product quality. In this study, the impacts of a particulate lubricant, a nano-disperse flow additive and liquid grinding aids on the dry fine milling and subsequent tableting of the ground material were investigated for three different organic model compounds. It is presented that the three additive classes cause varying and partly opposing effects during these process steps. Especially the lubricant and the grinding aids were shown to increase the efficiency of the milling process as well as the product fineness of the ground material, and to avoid critical product adhesions on the machine surfaces. Thereby, stable and efficient grinding conditions were partially not possible without the addition of such additives. However, as these positive effects are attributed to a reduction of the adhesive forces between the particles, much lower tablet strengths were achieved for these additives. This propagation of powder, and in turn, final product properties over whole process chains, has not been studied in detail so far. It was further revealed that the material behavior and the microstructure of the product particles is decisive for the processing as well, which is why additive effects may be product-specific and can even be suppressed under certain processing conditions. In comparison to the process performances, the powder properties and surface energies of the product particles were less influenced by the additives. On the contrary, particle-based morphologies or deformation behavior seem to play a major role in comparison to inorganic materials. Thus, it can be stated that global bulk properties and surface energies provide first indications of powder behavior and susceptibility. However, additional specific properties need to be evaluated to more clearly understand the influences of additives.
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Affiliation(s)
- Lina Miethke
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
| | - Paul Prziwara
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
| | - Jan Henrik Finke
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
- Center of Pharmaceutical Engineering—PVZ, Technische Universität Braunschweig, 38106 Braunschweig, Germany
- Correspondence: (J.H.F.); (S.B.-F.)
| | - Sandra Breitung-Faes
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
- Correspondence: (J.H.F.); (S.B.-F.)
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Pérez-López FR, Phillips N, Vieira-Baptista P, Cohen-Sacher B, Fialho SCAV, Stockdale CK. Management of postmenopausal vulvovaginal atrophy: recommendations of the International Society for the Study of Vulvovaginal Disease. Gynecol Endocrinol 2021; 37:746-752. [PMID: 34169794 DOI: 10.1080/09513590.2021.1943346] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE To develop a best practice document for the management of postmenopausal vulvovaginal atrophy (VVA). METHOD Literature review carried out using clinical terms, treatments or interventions and comorbidity related to VVA. RESULTS There is a wide variety of interventions that may produce temporal benefits for VVA. However, there are significant limitations in scientific publications concerning VVA and related issues, including variable outcome evaluations, variability in population age range, and small, often underpowered sample sizes. Therapeutic management of VVA should follow a sequential order, considering women's age, symptoms, general health as well as treatment preference. Beneficial options include lubricants, moisturizers, vaginal estrogens (estradiol, estriol, promestriene, conjugated estrogens), androgens, prasterone, and laser application. In women with general menopausal symptoms who are candidates for systemic hormone therapy, the lowest effective dose should be used. Oral ospemifene is an effective selective estrogen receptor modulator to treat VVA. Systemic androgens have a limited role. Although laser procedures are commonly used, at this moment the International Society for the Study of Vulvovaginal Disease does not endorse its use out of the setting of clinical trials. Pelvic floor muscle training improves blood flow and elasticity of the vulvovaginal tissue. In breast cancer survivors, moisturizers and lubricants are first line therapy. However, limited absorption of low/ultra-low doses of estrogens suggests safety, especially in women under treatment with aromatase inhibitors. As clinical practice and available preparations vary between countries this text should be adapted to local circumstances. CONCLUSIONS There is a wide range of therapeutic options to individualize VVA treatments.
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Affiliation(s)
- Faustino R Pérez-López
- Department of Obstetrics and Gynecology, University of Zaragoza, Faculty of Medicine, Zaragoza, Spain
| | - Nancy Phillips
- Department Obstetrics, Gynecology and Reproductive Sciences, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Pedro Vieira-Baptista
- Hospital Lusíadas Porto, Porto, Portugal
- LAP, Unilabs, Porto, Portugal
- Lower Genital Tract Unit, Centro Hospitalar de São João, Porto, Portugal
| | - Bina Cohen-Sacher
- Department of Obstetrics and Gynecology, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel
| | - Susana C A V Fialho
- Department of Obstetrics and Gynecology, Universidade Federal Fluminense Niterói, Rio de Janeiro, Brazil
| | - Colleen K Stockdale
- Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
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Rudszuck T, Zick K, Groß D, Nirschl H, Guthausen G. Dedicated NMR sensor to analyze relaxation and diffusion in liquids and its application to characterize lubricants. Magn Reson Chem 2021; 59:825-834. [PMID: 33754398 DOI: 10.1002/mrc.5155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/10/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
A dedicated nuclear magnetic resonance (NMR) sensor was designed for the analysis of liquids. The magnets are arranged in a V shape, creating a spatially dependent magnetic field in the gap. Measurements of samples with diverse diameters are possible underdefined magnetic field gradients at a given position. The magnet thus combines properties of single sided NMR with high static magnetic field gradients and classical time domain (TD) devices with lower to almost zero gradients. The sensor can easily be adapted to the requirements of the considered investigation; probes can be customized. On the example of lubricants and their aging, the added value and applicability of this sensor in quality control are highlighted in this publication. Relaxation and diffusion were measured by Carr-Purcell-Meiboom-Gill (CPMG) while varying the echo time τe and quantified via numerical modeling. Especially, relaxation shows a high sensitivity towards aging of lubricants such as particulate abrasion and changes in molecular dynamics induced, for example, by additive depletion. The applicability of this NMR sensor in quality control is demonstrated on the example of engine and transmission oils as well as of lubrication greases.
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Affiliation(s)
- Thomas Rudszuck
- Institute for Mechanical Engineering and Mechanics, KIT, Karlsruhe, Germany
| | - Klaus Zick
- Bruker BioSpin GmbH, Rheinstetten, Germany
| | | | - Hermann Nirschl
- Institute for Mechanical Engineering and Mechanics, KIT, Karlsruhe, Germany
| | - Gisela Guthausen
- Institute for Mechanical Engineering and Mechanics, KIT, Karlsruhe, Germany
- Engler-Bunte Institut, Water Science and Technology, KIT, Karlsruhe, Germany
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Sett S, Oh J, Cha H, Veriotti T, Bruno A, Yan X, Barac G, Bolton LW, Miljkovic N. Lubricant-Infused Surfaces for Low-Surface-Tension Fluids: The Extent of Lubricant Miscibility. ACS Appl Mater Interfaces 2021; 13:23121-23133. [PMID: 33949848 DOI: 10.1021/acsami.1c02716] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Lubricant-infused surfaces (LISs) and slippery liquid-infused porous surfaces (SLIPSs) have shown remarkable success in repelling low-surface-tension fluids. The atomically smooth, defect-free slippery surface leads to reduced droplet pinning and omniphobicity. However, the presence of a lubricant introduces liquid-liquid interactions with the working fluid. The commonly utilized lubricants for LISs and SLIPSs, although immiscible with water, show various degrees of miscibility with organic polar and nonpolar working fluids. Here, we rigorously investigate the extent of miscibility by considering a wide range of liquid-vapor surface tensions (12-73 mN/m) and different categories of lubricants having a range of viscosities (5-2700 cSt). Using high-fidelity analytical chemistry techniques including X-ray photoelectron spectroscopy, nuclear magnetic resonance, thermogravimetric analysis, and two-dimensional gas chromatography, we quantify lubricant miscibility to parts per billion accuracy. Furthermore, we quantify lubricant concentrations in the collected condensate obtained from prolonged condensation experiments with ethanol and hexane to delineate mixing and shear-based lubricant drainage mechanisms and to predict the lifetime of LISs and SLIPSs. Our work not only elucidates the effect of lubricant properties on miscibility with various fluids but also develops guidelines for developing stable and robust LISs and SLIPSs.
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Affiliation(s)
- Soumyadip Sett
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Junho Oh
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Hyeongyun Cha
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - Tincuta Veriotti
- BP Corporation North America, Inc., 150 West Warrenville Road, Naperville, Illinois 60563, United States
| | - Alessandra Bruno
- BP Corporation North America, Inc., 150 West Warrenville Road, Naperville, Illinois 60563, United States
| | - Xiao Yan
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
| | - George Barac
- BP Corporation North America, Inc., 150 West Warrenville Road, Naperville, Illinois 60563, United States
| | - Leslie W Bolton
- BP plc, Chertsey Road, Sunbury-on-Thames, Middlesex TW16 7LN, U.K
| | - Nenad Miljkovic
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, United States
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
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Jiwa N, Ozalp Y, Yegen G, Aksu B. Critical Tools in Tableting Research: Using Compaction Simulator and Quality by Design (QbD) to Evaluate Lubricants' Effect in Direct Compressible Formulation. AAPS PharmSciTech 2021; 22:151. [PMID: 33977355 DOI: 10.1208/s12249-021-02004-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/27/2021] [Indexed: 11/30/2022] Open
Abstract
As commonly known, the product development stage is quite complex, requires intensive knowledge, and is time-consuming. The selection of the excipients with the proper functionality and their corresponding levels is critical to drug product performance. The objective of this study was to apply quality by design (QbD) principles for formulation development and to define the desired product quality profile (QTPP) and critical quality attributes (CQA) of a product. QbD is a risk- and science-based holistic approach for upgraded pharmaceutical development. In this study, Ibuprofen DC 85W was used as a model drug, Cellactose® 80 along with MicroceLac® 100 as a filler, and magnesium stearate, stearic acid, and sodium stearyl fumarate as lubricants. By applying different formulation parameters to the filler and lubricants, the QbD approach furthers the understanding of the effect of critical formulation and process parameters on CQAs and the contribution to the overall quality of the drug product. An experimental design study was conducted to determine the changes of the obtained outputs of the formulations, which were evaluated using the Modde Pro 12.1 statistical computer program that enables optimization by modeling complex relationships. The results of the optimum formulation revealed that MicroceLac® 100 was the superior filler, while magnesium stearate at 1% was the optimum lubricant. A design space that indicates the safety operation limits for the process and formulation variables was also created. This study enriches the understanding of the effect of excipients in formulation and assists in enhancing formulation design using experimental design and mathematical modeling methods in the frame of the QbD approach.
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Taha-Tijerina J, Aviña K, Martínez JM, Arquieta-Guillén PY, González-Escobedo M. Carbon Nanotori Structures for Thermal Transport Applications on Lubricants. Nanomaterials (Basel) 2021; 11:1158. [PMID: 33946681 DOI: 10.3390/nano11051158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/23/2021] [Accepted: 04/25/2021] [Indexed: 12/02/2022]
Abstract
Carbon nanostructures have been recently applied to improve industrial manufacturing processes and other materials; such is the case for lubricants used in the metal-mechanic industry. Nanotori are toroidal carbon nanostructures, obtained from chemical treatment of multi-wall carbon nanotubes (MWCNTs). This material has been shown to have superb anti-wear and friction reduction performance, having the ability to homogeneously disperse within water in concentrations between 1–2 wt.%. Obtained results of these novel nanostructures under water mixtures and novel additives were a set point to our studies in different industrial lubricants. In the present work, nanotori structures have been applied in various filler fractions as reinforcement to evaluate the behavior in thermal transport of water-based (WB) and oil-based (OB) lubricants. Temperature-dependent experiments to evaluate the thermal conductivity were performed using a thermal water bath ranging from room temperature up to 323 K. The obtained results showed a highly effective and favorable improvement in the heat transport of both lubricants; oil-based results were better than water-based results, with nanotori structures increasing the lubricants’ thermal transport properties by 70%, compared to pure lubricant.
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Abstract
The eyelids are a delicate and complex dynamic structure with primary function to protect the eye surface. The term «meibomian gland dysfunction» (MGD) first appeared in the mid-1980s. This lesion is known to result in a disturbance of the tear film, eye irritation symptoms, clinically significant inflammation and diseases of the eye surface. The progression of MGD leads to hyperosmolarity of the tear film, its instability, an increase in the bacterial load of the eyelid margin, blepharitis and generalized inflammation of the ocular surface. For patients who require surgical treatment, a healthy eyelid is very important. Despite postoperative functional recovery, most of these patients experience dry eye syndrome (DES), which can lead to symptoms of eye irritation and deterioration of visual acuity due to instability of the tear film. In the early stages of MGD, it is advisable to begin treatment with a conversation about correct frequent blinking, rest during visual activity, adequate water intake, and a specific diet. Later, patients are advised to use an ultrasonic air humidifier, warm dry compresses, practice proper eyelid hygiene and perform massages, apply preservative-free lubricants, azithromycin, omega-3 preparations, and undergo local anti-inflammatory therapy. In case of a tick-borne infestation, the International Expert Group recommends the use of scrubs with 50% tea tree oil for treating the eyelids. In order to achieve a long-term effect or permanent remission, it is necessary to practice daily eyelid hygiene with the help of gels, special napkins and shampoos over a long period of time. Correctly selected medical treatment in accordance with the stage of the disease supplemented with massages and warm dry compresses lead to a significant improvement in the quality of life of patients with MGD and DES. The simplicity of eyelid hygiene is currently ensured by the availability of tools specially designed for the safe treatment of its edges, which have a complex histological and anatomical structure.
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Affiliation(s)
- I A Riks
- Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
| | - S V Trufanov
- Research Institute of Eye Diseases, Moscow, Russia
| | - R Boutaba
- Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
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Kennedy CE, Yeh PT, Li J, Gonsalves L, Narasimhan M. Lubricants for the promotion of sexual health and well-being: a systematic review. Sex Reprod Health Matters 2021; 29:2044198. [PMID: 35315312 PMCID: PMC8942543 DOI: 10.1080/26410397.2022.2044198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
AbstractPromoting sexual health is a World Health Organization (WHO) priority. Lubricants are widely available and used to improve sexual pleasure and reduce pain during intercourse. To inform WHO's self-care interventions guideline, we conducted a systematic review of the peer-reviewed literature to answer the question: does use of lubricants during or prior to sex result in improved sexual health and well-being. We searched PubMed, CINAHL, LILACS and EMBASE on 8 July 2020 for effectiveness, values and preferences, and cost data related to commercially available vaginal and anal lubricants. Data were systematically extracted and qualitatively synthesised. Effectiveness evidence was summarised in GRADE evidence profiles. Seven studies met the effectiveness review criteria. Two randomised trials found lubricant use led to improved female sexual well-being and had no impact on incidence of human papillomavirus (moderate certainty evidence). One observational study with gay and bisexual men showed lubricants were associated with increased reports of pain during receptive intercourse and no difference in pain during insertive intercourse, but a reduced degree of pain in both types of intercourse (low/very low certainty evidence). One observational study with female breast cancer survivors found better outcomes of vaginal dryness and dyspareunia with lubricant use (very low certainty evidence). Twenty-one values and preferences studies from diverse populations globally found that most individuals supported lubricant use for reasons of comfort/reduced pain and sexual pleasure. No cost studies were identified. Although evidence is limited, lubricants appear to offer an acceptable approach to improving sexual health and well-being.
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Affiliation(s)
- Caitlin E Kennedy
- Associate Professor, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. Correspondence:
| | - Ping Teresa Yeh
- Research Associate, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jingjia Li
- Research Assistant, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Lianne Gonsalves
- Technical Officer, Department of Antimicrobial Resistance, World Health Organization, Geneva, Switzerland
| | - Manjulaa Narasimhan
- Scientist, Department of Sexual and Reproductive Health and Research, World Health Organization, (includes the UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction - HRP), Geneva, Switzerland
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18
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Hu J, Andablo-Reyes E, Mighell A, Pavitt S, Sarkar A. Dry mouth diagnosis and saliva substitutes-A review from a textural perspective. J Texture Stud 2020; 52:141-156. [PMID: 33274753 DOI: 10.1111/jtxs.12575] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/17/2020] [Accepted: 11/25/2020] [Indexed: 12/15/2022]
Abstract
The aim of this review is to assess the objective and subjective diagnosis, as well as symptomatic topical treatment of dry mouth conditions with a clear focus on textural perspective. We critically examine both the current practices as well as outline emerging possibilities in dry mouth diagnosis and treatment, including a patent scan for saliva substitutes. For diagnosis, salivary flow rates and patient-completed questionnaires have proven to be useful tools in clinical practice. To date, objective measurements of changes in mechanical properties of saliva via rheological, adsorption, and tribological measurements and biochemical properties of saliva such as assessing protein, mucins (MUC5B) are seldom incorporated into clinical diagnostics; these robust diagnostic tools have been largely restricted to application in non-clinical settings. As for symptomatic treatments of dry mouth, four key agents including lubricating, thickening, adhesive, and moisturizing agents have been identified covering the overall landscape of commercial saliva substitutes. Although thickening agents such as modified celluloses, polysaccharide gum, polyethylene glycol, and so forth are most commonly employed saliva substitutes, they offer short-lived relief from dry mouth and generally do not provide boundary lubrication properties of real human saliva. Innovative technologies such as self-assembly, emulsion, liposomes, and microgels are emerging as novel saliva substitutes hold promise for alternative approaches for efficient moistening and lubrication of the oral mucosa. Their adoption into clinical practice will depend on their efficacies, duration of relief, and ease of application by the practitioners and patient compliance.
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Affiliation(s)
- Jing Hu
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, Faculty of Environment, University of Leeds, Leeds, UK
| | - Efren Andablo-Reyes
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, Faculty of Environment, University of Leeds, Leeds, UK
| | - Alan Mighell
- School of Dentistry, Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Sue Pavitt
- School of Dentistry, Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, Faculty of Environment, University of Leeds, Leeds, UK
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Di Lecce S, Kornyshev AA, Urbakh M, Bresme F. Lateral Ordering in Nanoscale Ionic Liquid Films between Charged Surfaces Enhances Lubricity. ACS Nano 2020; 14:13256-13267. [PMID: 33054180 DOI: 10.1021/acsnano.0c05043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Electric fields modify the structural and dynamical properties of room temperature ionic liquids (RTILs) providing a physical principle to develop tunable lubrication devices. Using nonequilibrium molecular dynamics atomistic simulations, we investigate the impact of the composition of imidazolium RTILs on the in-plane ordering of ionic layers in nanogaps. We consider imidazolium cations and widely used anions featuring different molecular structures, spherical ([BF4]-), elongated surfactant-like ([C2SO4]-), and elongated with a more delocalized charge ([NTf2]-). The interplay of surface charge, surface polarity, and anion geometry enables the formation of crystal-like structures in [BF4]- and [NTf2]- nanofilms, while [C2SO4]- nanofilms form disordered layers. We study how the ordering of the ionic liquid lubricant in the nanogap affects friction. Counterintuitively, we find that the friction force decreases with the ability of the RTILs to form crystal-like structures in the confined region. The crystallization can be activated or inhibited by changing the polarity of the surface, providing a mechanism to tune friction with electric fields.
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Affiliation(s)
- Silvia Di Lecce
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, W12 0BZ London, U.K
| | - Alexei A Kornyshev
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, W12 0BZ London, U.K
| | - Michael Urbakh
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Fernando Bresme
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, W12 0BZ London, U.K
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Abstract
Recurrent corneal erosion syndrome (RCES) is a common chronic disease associated with repeated episodes of epithelial disruption and is characterized by sudden onset of sharp pain in the eye, usually at night or upon waking, as well as redness, photophobia and lacrimation. The cause of the disease is considered to be impaired adhesion of the epithelial layer to the stroma, which is a consequence of abnormal regeneration of the basement membrane of corneal epithelium. A number of biological factors, including inflammatory mediators and proteinases in high concentrations, contribute to the destruction of the formed adhesion complexes. The basis of RCES diagnosis is characteristic medical history and biomicroscopy. An area of epithelium absence can be detected under direct illumination - more often in paracentral view - mainly in the lower third of the cornea, where an area of loose and irregular epithelium with microcysts or grayish inclusions can be seen. There may also be a card-like or «fingerprint» pattern. First of all, it is necessary to differentiate RCES from infectious lesions, which require a fundamentally different treatment regimen. It is believed that the first stage of treatment should include lubricants, drugs that promote epithelialization, inhibitors of matrix metalloproteinases and lipases. The «second line» of conservative treatment can include blood derivatives. If conservative therapy is ineffective, it is advised to use phototherapeutic keratectomy (PTK) or perform diamond burr polishing of Bowman's layer. The choice of a method for treating recurrent erosion should be based on the effectiveness of drug therapy, frequency of recurrence, duration of the disease, severity of clinical symptoms, availability of specific ophthalmic equipment and experience with it.
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Affiliation(s)
- S V Trufanov
- Research Institute of Eye Diseases, Moscow, Russia
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Kim SJ, Park B, Huh HW, Na YG, Kim M, Han M, Lee H, Pham TMA, Lee HK, Lee JY, Kim CS, Baek JS, Cho CW. Achyranthis radix Extract-Loaded Eye Drop Formulation Development and Novel Evaluation Method for Dry Eye Treatment. Pharmaceutics 2020; 12:pharmaceutics12020165. [PMID: 32079194 PMCID: PMC7076473 DOI: 10.3390/pharmaceutics12020165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 12/11/2022] Open
Abstract
Recently, Achyranthis radix extract has been studied as a therapeutic agent for dry eye disease that occurs from fine dust. The aim of this study was the development of Achyranthis radix extract-loaded eye drop formulations using lubricants, generally used for artificial tear eye drops. Ecdysterone was used as a marker compound for Achyranthis radix extract and 1% Achyranthis radix extract solution contained 14.37 ± 0.04 μg/mL of ecdysterone. Before formulation studies, a new method was performed to evaluate pigmentation, which might be caused by eye drops of herbal extract. A comparative study of the water retention ability of each formulation and ability to prevent the death of conjunctival epithelial cells in dry conditions was conducted. Moreover, treatment of Achyranthis radix extract (USL) eye drop formulation exhibited a significant inhibitory effect on inflammation in a concentration-dependent manner. The long-term and accelerated stability tests showed that lubricants could contribute to the stability of herbal extracts in solution. In conclusion, hyaluronic acid showed a good effect on the development of eye drop formulation using Achyranthis radix extracts for treating dry eye disease.
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Affiliation(s)
- Sung-Jin Kim
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Bongkyun Park
- Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea; (B.P.); (C.-S.K.)
| | - Hyun Wook Huh
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Young-Guk Na
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Minki Kim
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Mingu Han
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Hyunmin Lee
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Thi Mai Anh Pham
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Hong-Ki Lee
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Jae-Young Lee
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
| | - Chan-Sik Kim
- Clinical Medicine Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea; (B.P.); (C.-S.K.)
- Korean Convergence Medicine, University of Science and Technology (UST), Daejeon 34054, Korea
| | - Jong-Suep Baek
- Department of Herbal Medicine Resource, Kangwon National University, 346 Hwangjo-gil, Dogye-eup, Samcheok-si, Gangwon-do 25949, Korea;
| | - Cheong-Weon Cho
- College of Pharmacy and Institute of Drug Research & Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea; (S.-J.K.); (H.W.H.); (Y.-G.N.); (M.K.); (M.H.); (H.L.); (T.M.A.P.); (H.-K.L.); (J.-Y.L.)
- Correspondence: ; Tel.: +82-42-821-5934
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Zhang J, Ewen JP, Ueda M, Wong JSS, Spikes HA. Mechanochemistry of Zinc Dialkyldithiophosphate on Steel Surfaces under Elastohydrodynamic Lubrication Conditions. ACS Appl Mater Interfaces 2020; 12:6662-6676. [PMID: 31913008 DOI: 10.1021/acsami.9b20059] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Zinc dialkyldithiophosphate (ZDDP) is added to engine lubricants to reduce wear and ensure reliable operation. ZDDP reacts under rubbing conditions to form protective zinc/iron phosphate tribofilms on steel surfaces. Recently, it has been demonstrated that this process can be promoted by applied stresses in lubricated contacts, as well as temperature, and is thus mechanochemical in origin. In this study, a tribology test rig, capable of applying very high loads, has been developed to generate ZDDP tribofilms under full-film elastohydrodynamic lubrication (EHL) conditions in steel/steel ball-on-disk contacts. This provides a well-defined temperature and stress environment with negligible direct asperity contact in which to study mechanochemical processes. ZDDPs with branched primary and secondary alkyl substituents have been studied in three base oils, two with high EHL friction and one with low EHL friction. In the high EHL friction base oils, the tribofilm growth rate increases exponentially with shear stress and temperature for both ZDDPs, as predicted by a stress-augmented thermal activation model. Conversely, under otherwise identical conditions, negligible ZDDP tribofilm formation takes place in the low EHL friction base oil. This confirms that the ZDDP reaction is driven by macroscopic shear stress rather than hydrostatic pressure. The secondary ZDDP forms tribofilms considerably faster than the primary ZDDP under equivalent conditions, suggesting that the initial decomposition reaction is the rate-determining step for tribofilm formation. The rate of tribofilm growth is independent of ZDDP concentration over the range studied, indicating that this process follows zero-order kinetics. Under full-film EHL conditions, ZDDP tribofilm formation is promoted by macroscopic shear stress applied through the base oil molecules, which induces asymmetric stress on adsorbed ZDDP molecules to promote their decomposition and initiate rapid phosphate polymerization.
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Affiliation(s)
- Jie Zhang
- Department of Mechanical Engineering , Imperial College London , London SW7 2AZ , U.K
| | - James P Ewen
- Department of Mechanical Engineering , Imperial College London , London SW7 2AZ , U.K
| | - Mao Ueda
- Department of Mechanical Engineering , Imperial College London , London SW7 2AZ , U.K
| | - Janet S S Wong
- Department of Mechanical Engineering , Imperial College London , London SW7 2AZ , U.K
| | - Hugh A Spikes
- Department of Mechanical Engineering , Imperial College London , London SW7 2AZ , U.K
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23
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Di Lecce S, Kornyshev AA, Urbakh M, Bresme F. Electrotunable Lubrication with Ionic Liquids: the Effects of Cation Chain Length and Substrate Polarity. ACS Appl Mater Interfaces 2020; 12:4105-4113. [PMID: 31875392 DOI: 10.1021/acsami.9b19283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electrotunable lubrication with ionic liquids (ILs) provides dynamic control of friction with the prospect to achieve superlubrication. We investigate the dependence of the frictional and structural forces with 1-n,2-methyl-imidazolium tetrafluoroborate [CnMIM]+[BF4]- (n = 2, 4, 6) ILs as a lubricant on the molecular structure of the liquid, normal load, and polarity of the electrodes. Using non-equilibrium molecular dynamics simulations and coarse-grained force-fields, we show that the friction force depends significantly on the chain length of the cation. ILs containing cations with shorter aliphatic chains show lower friction forces, ∼40% for n = 2 as compared to the n = 6 case, and more resistance to squeeze-out by external loads. The normal load defines the dynamic regime of friction, and it determines maxima in the friction force at specific surface charges. At relatively low normal loads, ∼10 MPa, the velocity profile in the confined region resembles a Couette type flow, whereas at high loads, >200 MPa, the motion of the ions is highly correlated and the velocity profile resembles a "plug" flow. Different dynamic regimes result in distinctive slippage planes, located either at the IL-electrode interface or in the interior of the film, which ultimately lead, at high loads, to the observation of maxima in the friction force at specific surface charge densities. Instead, at low loads the maxima are not observed, and the friction is found to monotonously increase with the surface charge. Friction with [CnMIM]+[BF4]- as a lubricant is reduced when the liquid is confined between positively charged electrodes. This is due to better lubricating properties and enhanced resistance to squeeze out when the anion [BF4]- is in direct contact with the electrode.
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Affiliation(s)
- Silvia Di Lecce
- Department of Chemistry, Molecular Sciences Research Hub , Imperial College , W12 0BZ London , U.K
| | - Alexei A Kornyshev
- Department of Chemistry, Molecular Sciences Research Hub , Imperial College , W12 0BZ London , U.K
| | - Michael Urbakh
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science , Tel Aviv University , Tel Aviv 6997801 , Israel
| | - Fernando Bresme
- Department of Chemistry, Molecular Sciences Research Hub , Imperial College , W12 0BZ London , U.K
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Hua J, Shi Y. Non-corrosive Green Lubricant With Dissolved Lignin in Ionic Liquids Behave as Ideal Lubricants for Steel-DLC Applications. Front Chem 2019; 7:857. [PMID: 31867310 PMCID: PMC6908516 DOI: 10.3389/fchem.2019.00857] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 11/25/2019] [Indexed: 11/13/2022] Open
Abstract
Diamond-like carbon (DLC)–steel contacts become more and more popular in the industry now. Since the surface chemical properties of DLC are quite different from those of iron, traditional formulated lubricants have problems to form tribo-chemical films, which are effective to improve the tribological performance for steel-steel contacts, on the surface of DLC. Thus, new lubricants formulation strategies are needed to be considered for steel-DLC applications. A kind of green lubricant (lignin-[Choline][L-Proline] (L-[CH][Pro])) without any traditional tribo-chemical active element, i.e., free of P, S, B, etc., was studied in this paper for the steel-DLC contact. To find the difference between this new ILs and the traditional lubricants, a commercially available fully formulated lubricant was used as a reference. An Optimol SRV-III oscillating friction and wear tester was used to evaluate the tribological performance. Three different kinds of commercially available DLC coatings (Tribobond 40(Cr + a-C:H:W), Tribobond 43 [(Cr+) a-C:H), and Tribobond 44(a-C:Cr)] were investigated. The results show that the ILs exhibit an obviously lower friction coefficient than that of the traditional commercially available fully formulated lubricant. Among those three DLC coatings, the (Cr+) a-C:H DLC coating exhibits the biggest improvement of wear resistance lubricated with the new ILs than that of the commercially available fully formulated lubricant. It's expected that its excellent tribological properties are attributed to the affinity of the ILs to the metal surface and the strength of the ionic liquids interactions by hydrogen bonding. Thus, forming strong physical adsorption strategy, instead of forming chemical tribo-films, is recommended to enhance the lubricating performance of lubricants for DLC.
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Affiliation(s)
- Jing Hua
- Division of Machine Elements, Luleå University of Technology, Luleå, Sweden
| | - Yijun Shi
- Division of Machine Elements, Luleå University of Technology, Luleå, Sweden
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25
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Norton AM, Liu S, Saha B, Vlachos DG. Branched Bio-Lubricant Base Oil Production through Aldol Condensation. ChemSusChem 2019; 12:4780-4785. [PMID: 31493309 DOI: 10.1002/cssc.201901838] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/07/2019] [Indexed: 06/10/2023]
Abstract
Currently, lubricant base oils are derived from petroleum, a nonrenewable feedstock that contributes to greenhouse gas emissions. Bioderived, renewable lubricant base oils can mitigate environmental challenges and offer superior cold flow properties by incorporating branches to the base oil's hydrocarbon backbone with an appropriate synthetic strategy. A strategy was developed to synthesize branched alkanes for lubricant base oil in two steps from 12-tricosanone, obtained from bioderived fatty acids, and furfural, obtained from lignocellulosic biomass. The reaction pathway involves carbon-carbon coupling through aldol condensation followed by hydrodeoxygenation (HDO). Various solvents (non-polar, aprotic and polar, protic) and reaction conditions were screened to achieve a maximum yield of 94.3 % of aldol condensation products, containing the majority of a C33 furan (79.5 %) followed by a C28 furan (14.8 %). Subsequent HDO of aldol condensation products over an Ir-ReOx /SiO2 catalyst produced lubricant-ranged branched alkanes (C28 and C33 ) with 61.4 % yield and small fractions (<11 %) of alkanes with carbon numbers between C15 and C10 . The viscous properties of the produced bio-lubricant base oil were comparable to commercial petroleum-derived Group III and Group IV base oils. This approach serves as a potential stepping-stone to replace petroleumderived base oils and, in turn, reduce greenhouse gas emissions associated with current lubricant production.
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Affiliation(s)
- Angela M Norton
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy St., Newark, DE, 19716, USA
- Department of Chemical and Biomolecular Engineering, University of Delaware, 221 Academy St., Newark, DE, 19716, USA
| | - Sibao Liu
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy St., Newark, DE, 19716, USA
| | - Basudeb Saha
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy St., Newark, DE, 19716, USA
| | - Dionisios G Vlachos
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy St., Newark, DE, 19716, USA
- Department of Chemical and Biomolecular Engineering, University of Delaware, 221 Academy St., Newark, DE, 19716, USA
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Zaarour M, El Siblani H, Arnault N, Boullay P, Mintova S. Zeolite Nanocrystals Protect the Performance of Organic Additives and Adsorb Acid Compounds during Lubricants Oxidation. Materials (Basel) 2019; 12:E2830. [PMID: 31484294 DOI: 10.3390/ma12172830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 11/16/2022]
Abstract
Zeolite nanocrystals were used as proactive agents to extend the lifetime of commercial lubricants by protecting the performance additives from depletion and adsorbing the acid formed during oxidation. The nanosized zeolites were introduced into four lubricants and subjected to oxidation (90 °C and 150 °C). A strong affinity towards protection of zinc dialkyldithiophosphate (ZDDP) additive was demonstrated by 31P NMR (nuclear magnetic resonance) and FTIR (fourier-transform infrared) spectroscopy even after heating at 150 °C for 24 h. FTIR profiles of lubricants aged in the presence of LTL (Linde Type L zeolite) showed lower oxidation degree while the formed oxidation products (aldehydes, ketones, and acids) were adsorbed on the zeolite crystals acting as scavengers.
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Rudszuck T, Förster E, Nirschl H, Guthausen G. Low-field NMR for quality control on oils. Magn Reson Chem 2019; 57:777-793. [PMID: 30790362 DOI: 10.1002/mrc.4856] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/12/2019] [Accepted: 02/14/2019] [Indexed: 05/15/2023]
Abstract
Oil is a prominent, but multifaceted material class with a wide variety of applications. Technical oils, crude oils as well as edibles are main subclasses. In this review, the question is addressed how low-field NMR can contribute in oil characterization as an analytical tool, mainly with respect to quality control. Prerequisite in the development of a quality control application, however, is a detailed understanding of the oils and of the measurement. Low-field NMR is known as a rich methodical toolbox that was and is explored and further developed to address questions about oils, their quality, and usability as raw materials, during production and formulation as well as in use.
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Affiliation(s)
- Thomas Rudszuck
- Institute for Mechanical Engineering and Mechanics, Karlsruher Institute of Technology (KIT), Karlsruhe, Germany
| | - Eva Förster
- Institute for Mechanical Engineering and Mechanics, Karlsruher Institute of Technology (KIT), Karlsruhe, Germany
| | - Hermann Nirschl
- Institute for Mechanical Engineering and Mechanics, Karlsruher Institute of Technology (KIT), Karlsruhe, Germany
| | - Gisela Guthausen
- Institute for Mechanical Engineering and Mechanics, Karlsruher Institute of Technology (KIT), Karlsruhe, Germany
- Engler-Bunte Institute, Water Science and Technology, Karlsruher Institute of Technology (KIT), Karlsruhe, Germany
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Kassler A, Pittenauer E, Doerr N, Allmaier G. Development of an accelerated artificial ageing method for the characterization of degradation products of antioxidants in lubricants by mass spectrometry. Eur J Mass Spectrom (Chichester) 2019; 25:300-323. [PMID: 30400753 DOI: 10.1177/1469066718811714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The understanding of ageing mechanisms of antioxidants in base oils is indispensable for the development of improved lubricants. In this study, a novel artificial ageing method based on the application of peroxide as oxidant is presented for improved monitoring of thermo-oxidative degradation processes in combination with mass spectrometry. Model oils containing aminic and phenolic antioxidants were aged and chemical structures of their oxidation products were elucidated by ultrahigh performance liquid chromatography and electrospray ionization high resolution (Orbitrap) mass spectrometry. Additionally, synergistic mixtures of four antioxidants were investigated, because the formation of condensed molecules from amines and phenols would have a major influence on the antioxidant potential but could not be detected in the bulk lubricant.
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Affiliation(s)
- Alexander Kassler
- 1 Institute of Chemical Technologies and Analytics, TU Wien (Vienna University of Technology), Vienna, Austria
- 2 Austrian Center of Competence for Tribology (AC2T Research GmbH), Wiener Neustadt, Austria
| | - Ernst Pittenauer
- 1 Institute of Chemical Technologies and Analytics, TU Wien (Vienna University of Technology), Vienna, Austria
| | - Nicole Doerr
- 2 Austrian Center of Competence for Tribology (AC2T Research GmbH), Wiener Neustadt, Austria
| | - Guenter Allmaier
- 1 Institute of Chemical Technologies and Analytics, TU Wien (Vienna University of Technology), Vienna, Austria
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29
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Laesecke A, Junker C, Lauria DS. Viscosity Measurements of Three Base Oils and One Fully Formulated Lubricant and New Viscosity Correlations for the Calibration Liquid Squalane. J Res Natl Inst Stand Technol 2019; 124:1-41. [PMID: 34877175 PMCID: PMC7340553 DOI: 10.6028/jres.124.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/13/2018] [Indexed: 06/13/2023]
Abstract
The viscosities of three pentaerythritol tetraalkanoate ester base oils and one fully formulated lubricant were measured with an oscillating piston viscometer in the overall temperature range from 275 K to 450 K with pressures up to 137 MPa. The alkanoates were pentanoate, heptanoate, and nonanoate. Three sensing cylinders covering the combined viscosity range from 1 mPa·s to 100 mPa·s were calibrated with squalane. This required a re-correlation of a squalane viscosity data set in the literature that was measured with a vibrating wire viscometer, with an estimated extended uncertainty of 2 %, because the squalane viscosity formulations in the literature did not represent this data set within its experimental uncertainty. In addition, a new formulation for the viscosity of squalane at atmospheric pressure was developed that represents experimental data from 169.5 K to 473 K within their estimated uncertainty over a viscosity range of more than eleven orders of magnitude. The viscosity of squalane was measured over the entire viscometer range, and the results were used together with the squalane correlations to develop accurate calibrating functions for the instrument. The throughput of the instrument was tripled by a custom-developed LabVIEW application. The measured viscosity data for the ester base oils and the fully formulated lubricant were tabulated and compared with literature data. An unpublished viscosity data set for pentaerythritol tetrapentanoate measured in this laboratory in 2006 at atmospheric pressure from 253 K to 373 K agrees with the new data within their experimental uncertainty and confirms the deviations from the literature data. The density data measured in this project for the three base oils deviate from the literature data in a way that is by sign and magnitude consistent with the deviations of the viscosity data. This points to differences in the sample compositions as the most likely cause for the deviations.
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Affiliation(s)
- Arno Laesecke
- National Institute of Standards and Technology, Boulder, CO 80305, USA
- retired from NIST
| | - Clemens Junker
- Institut für Thermodynamik, Helmut-Schmidt-Universität/Universität der Bundeswehr Hamburg, Holstenhofweg 85, D-22043 Hamburg, Germany
| | - Damian S Lauria
- National Institute of Standards and Technology, Boulder, CO 80305, USA
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30
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Nunes RD, Cascaes M, Schneider IJC, Traebert J. Effects of using lubricant during the speculum examination for Pap smear collection. Diagn Cytopathol 2018; 46:1040-1044. [PMID: 30284399 DOI: 10.1002/dc.24069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/09/2018] [Accepted: 08/13/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To evaluate the effect of using lubricant during speculum examination for Pap smear collection. METHODS A cross-sectional study was conducted involving 83 patients attending a medical school clinic. Participants were allocated into two groups: Group 1-Lubricant using; Group 2-No lubricant using. All patients were submitted to two successive collections and after were asked about their level of discomfort. Differences between groups regarding quality, artifacts, cytology, and level of discomfort were observed through chi-squared test. Odds ratios and 95% confidence intervals were also estimated. Statistical significance was set at P < .05. RESULTS No significant differences between groups regarding quality, presence of artifacts, and cytological results were observed. Significant lower discomfort level in Group 1 (lubricant using). CONCLUSION The use of vaginal lubricant did not affect the results of cytology and could be a useful tool to reduce the discomfort during Pap smear collection.
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Affiliation(s)
- Rodrigo Dias Nunes
- Faculty of Medicine, University of Southern Santa Catarina at Palhoça, Santa Catarina, Brazil.,Postgraduate Program in Health Sciences, University of Southern Santa Catarina at Palhoça, Santa Catarina, Brazil
| | - Maisa Cascaes
- Faculty of Medicine, University of Southern Santa Catarina at Palhoça, Santa Catarina, Brazil
| | - Ione Jayce Ceola Schneider
- Postgraduate Program in Health Sciences, University of Southern Santa Catarina at Palhoça, Santa Catarina, Brazil
| | - Jefferson Traebert
- Postgraduate Program in Health Sciences, University of Southern Santa Catarina at Palhoça, Santa Catarina, Brazil
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31
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Cooper BG, Chin SL, Xiao R, Buch K, Kim D, Grinstaff MW. Friction-lowering capabilities and human subject preferences for a hydrophilic surface coating on latex substrates: implications for increasing condom usage. R Soc Open Sci 2018; 5:180291. [PMID: 30473805 PMCID: PMC6227966 DOI: 10.1098/rsos.180291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 08/13/2018] [Indexed: 05/10/2023]
Abstract
Personal lubricants can increase user satisfaction with male condoms by reducing friction and yielding a slippery sensation. However, lubricants pose disadvantages of dilution in physiologic fluids and sloughing away over repeated articulations. To address these drawbacks, a latex surface modification, which becomes lubricious in the presence of physiologic fluid, has been developed and evaluated. This study assesses (i) the frictional performance of the lubricious coating compared to non-coated latex and latex lubricated by personal lubricant, (ii) the level of agreement between human-perceived slipperiness and machine-measured friction, and (iii) human preference for a hypothetical male condom containing the lubricious coating. Friction coefficient of the lubricious coating was 53% lower than that of non-coated latex and approximately equal to that afforded by personal lubricant. A touch test and survey of a small population sample (N = 33) revealed a strong correlation (R 2 = 0.83) between human-perceived slipperiness and machine-measured friction. A majority of participants (73%) expressed a preference for a condom containing the lubricious coating, agreeing that an inherently slippery condom that remained slippery for a long duration would increase their condom usage. Such a coating shows potential to be an effective strategy for decreasing friction-associated pain, increasing user satisfaction and increasing condom usage.
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Affiliation(s)
| | - Stacy L. Chin
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Ruiqing Xiao
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Karen Buch
- Department of Radiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Ducksoo Kim
- Department of Radiology, Boston University School of Medicine, Boston, MA 02118, USA
- Author for correspondence: Mark W. Grinstaff e-mail:
| | - Mark W. Grinstaff
- Department of Chemistry, Boston University, Boston, MA 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- Author for correspondence: Ducksoo Kim e-mail:
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32
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Kumara C, Leonard DN, Meyer HM, Luo H, Armstrong BL, Qu J. Palladium Nanoparticle-Enabled Ultrathick Tribofilm with Unique Composition. ACS Appl Mater Interfaces 2018; 10:31804-31812. [PMID: 30141901 DOI: 10.1021/acsami.8b11213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
There is a consensus that savings of 1.0-1.4% of a country's gross domestic product may be achieved through lubrication R&D. Recent studies have shown great potential for using surface-functionalized nanoparticles (NPs) as lubricant additives to enhance lubricating performance. NPs were reported with ability of producing a low-friction antiwear tribofilm, usually 20-200 nm in thickness, on the contact surface. In contrast, this study reports an unexpected 10 times thicker (2-3 μm) tribofilm formed by dodecanethiol-modified palladium NPs (core size: 2-4 nm) in boundary lubrication of a steel-cast iron contact. Adding 0.5-1.0 wt % such NPs to a lubricating oil resulted in significant reductions in friction and wear by up to 40 and 97%, respectively. Further investigation suggested that the PdNP core primarily was responsible for the improvement in both friction and wear, whereas the thiolate ligand only contributed to the wear protection but had little impact on the friction behavior. In addition, unlike most previously reported tribofilms that contain a substantial amount of metal oxides, this PdNP-induced tribofilm is clearly dominated by Pd/S compounds, as revealed by nanostructural examination and chemical analysis. Such a ultrathick tribofilm with unique composition is believed to be responsible for the superior lubricating behavior.
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Affiliation(s)
- Chanaka Kumara
- Department of Chemistry , University of Tennessee , Knoxville , Tennessee 37996 , United States
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33
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Abstract
Lubrication is involved in all root canal treatment phases, from dental dam placement to canal obturation. Most often associated with instrumentation, lubrication is required to facilitate the mechanical action of hand/rotary files and to help emulsify and suspend the debris produced. Aqueous irrigation solutions such as sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA) should be regarded as lubricants, but paste-type substances are marketed specifically for this purpose. As more patients demand the retention of challenging teeth with narrow and curved root canals, the importance of lubrication in all aspects of root canal treatment must be acknowledged.
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Affiliation(s)
- Nicholas Chandler
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Deepak Chellappa
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Bonse J, Kirner SV, Griepentrog M, Spaltmann D, Krüger J. Femtosecond Laser Texturing of Surfaces for Tribological Applications. Materials (Basel) 2018; 11:ma11050801. [PMID: 29762544 PMCID: PMC5978178 DOI: 10.3390/ma11050801] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/09/2018] [Accepted: 05/10/2018] [Indexed: 11/28/2022]
Abstract
Laser texturing is an emerging technology for generating surface functionalities on basis of optical, mechanical, or chemical properties. Taking benefit of laser sources with ultrashort (fs) pulse durations features outstanding precision of machining and negligible rims or burrs surrounding the laser-irradiation zone. Consequently, additional mechanical or chemical post-processing steps are usually not required for fs-laser surface texturing (fs-LST). This work aimed to provide a bridge between research in the field of tribology and laser materials processing. The paper reviews the current state-of-the-art in fs-LST, with a focus on the tribological performance (friction and wear) of specific self-organized surface structures (so-called ripples, grooves, and spikes) on steel and titanium alloys. On the titanium alloy, specific sickle-shaped hybrid micro-nanostructures were also observed and tribologically tested. Care is taken to identify accompanying effects affecting the materials hardness, superficial oxidation, nano- and microscale topographies, and the role of additives contained in lubricants, such as commercial engine oil.
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Affiliation(s)
- Jörn Bonse
- Bundesanstalt für Materialforschung und -Prüfung (BAM), Unter den Eichen 87, D-12205 Berlin, Germany.
| | - Sabrina V Kirner
- Bundesanstalt für Materialforschung und -Prüfung (BAM), Unter den Eichen 87, D-12205 Berlin, Germany.
| | - Michael Griepentrog
- Bundesanstalt für Materialforschung und -Prüfung (BAM), Unter den Eichen 87, D-12205 Berlin, Germany.
| | - Dirk Spaltmann
- Bundesanstalt für Materialforschung und -Prüfung (BAM), Unter den Eichen 87, D-12205 Berlin, Germany.
| | - Jörg Krüger
- Bundesanstalt für Materialforschung und -Prüfung (BAM), Unter den Eichen 87, D-12205 Berlin, Germany.
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35
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Gonzalez Rodriguez P, Dral AP, van den Nieuwenhuijzen KJH, Lette W, Schipper DJ, Ten Elshof JE. Thermochemical Stability and Friction Properties of Soft Organosilica Networks for Solid Lubrication. Materials (Basel) 2018; 11:E180. [PMID: 29364164 DOI: 10.3390/ma11020180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 01/11/2018] [Accepted: 01/22/2018] [Indexed: 11/23/2022]
Abstract
In view of their possible application as high temperature solid lubricants, the tribological and thermochemical properties of several organosilica networks were investigated over a range of temperatures between 25 and 580 °C. Organosilica networks, obtained from monomers with terminal and bridging organic groups, were synthesized by a sol-gel process. The influence of carbon content, crosslink density, rotational freedom of incorporated hydrocarbon groups, and network connectivity on the high temperature friction properties of the polymer was studied for condensed materials from silicon alkoxide precursors with terminating organic groups, i.e., methyltrimethoxysilane, propyltrimethoxysilane, diisopropyldimethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane and 4-biphenylyltriethoxysilane networks, as well as precursors with organic bridging groups between Si centers, i.e., 1,4-bis(triethoxysilyl)benzene and 4,4′-bis(triethoxysilyl)-1,1′-biphenyl. Pin-on-disc measurements were performed using all selected solid lubricants. It was found that materials obtained from phenyltrimethoxysilane and cyclohexyltrimethoxysilane precursors showed softening above 120 °C and performed best in terms of friction reduction, reaching friction coefficients as low as 0.01. This value is lower than that of graphite films (0.050 ± 0.005), a common bench mark for solid lubricants.
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Sett S, Yan X, Barac G, Bolton LW, Miljkovic N. Lubricant-Infused Surfaces for Low-Surface-Tension Fluids: Promise versus Reality. ACS Appl Mater Interfaces 2017; 9:36400-36408. [PMID: 28950702 DOI: 10.1021/acsami.7b10756] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The past few decades have seen substantial effort for the design and manufacturing of hydrophobic structured surfaces for enhanced steam condensation in water-based applications. Such surfaces promote dropwise condensation and easy droplet removal. However, less priority has been given to applications utilizing low-surface-tension fluids as the condensate. Lubricant-infused surfaces (LISs) or slippery liquid-infused porous surfaces (SLIPSs) have recently been developed, where the atomically smooth, defect-free slippery surface leads to reduced pinning of water droplets and omniphobic characteristics. The remarkable results of LISs and SLIPSs with a range of working fluid droplets give hope of their viability with low-surface-tension condensates. However, the presence of the additional liquid in the form of lubricant brings other issues to consider. Here, in an effort to study the dropwise condensation potential of LISs and SLIPSs, we investigate the miscibility of a range of low-surface-tension fluids with widely used lubricants in LIS and SLIPS design. We consider a wide range of condensate surface tensions (12-73 mN/m) and different categories of lubricants with varied viscosities (5-2700 cSt), namely, fluorinated Krytox oils, hydrocarbon silicone oils, mineral oil, and ionic liquids. In addition, we use both theory and pendant drop experiments to predict the cloaking behavior of the lubricants and immiscible condensate working fluid pairs. Our work not only shows that careful attention must be paid to lubricant-condensate selection to create long-lasting LISs or SLIPSs but also develops lubricant selection design guidelines for stable LISs and SLIPSs for enhanced condensation in applications utilizing low-surface-tension working fluids.
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Affiliation(s)
- Soumyadip Sett
- Department of Mechanical Science and Engineering, University of Illinois , Urbana, Illinois 61801, United States
| | - Xiao Yan
- Department of Mechanical Science and Engineering, University of Illinois , Urbana, Illinois 61801, United States
| | - George Barac
- BP International Limited , 150 W Warrenville Road, Naperville, Illinois 60563, United States
| | - Leslie W Bolton
- BP plc , Chertsey Road, Sunbury-on-Thames, Middlesex TW16 7LN, U.K
| | - Nenad Miljkovic
- Department of Mechanical Science and Engineering, University of Illinois , Urbana, Illinois 61801, United States
- Frederick Seitz Materials Research Laboratory, University of Illinois , Urbana, Illinois 61801, United States
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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Siddaiah A, Khan ZA, Ramachandran R, Menezes PL. Performance Analysis of Retrofitted Tribo-Corrosion Test Rig for Monitoring In Situ Oil Conditions. Materials (Basel) 2017; 10:E1145. [PMID: 28956819 DOI: 10.3390/ma10101145] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 11/17/2022]
Abstract
Oils and lubricants, once extracted after use from a mechanical system, can hardly be reused, and should be refurbished or replaced in most applications. New methods of in situ oil and lubricant efficiency monitoring systems have been introduced for a wide variety of mechanical systems, such as automobiles, aerospace aircrafts, ships, offshore wind turbines, and deep sea oil drilling rigs. These methods utilize electronic sensors to monitor the "byproduct effects" in a mechanical system that are not indicative of the actual remaining lifecycle and reliability of the oils. A reliable oil monitoring system should be able to monitor the wear rate and the corrosion rate of the tribo-pairs due to the inclusion of contaminants. The current study addresses this technological gap, and presents a novel design of a tribo-corrosion test rig for oils used in a dynamic system. A pin-on-disk tribometer test rig retrofitted with a three electrode-potentiostat corrosion monitoring system was used to analyze the corrosion and wear rate of a steel tribo-pair in industrial grade transmission oil. The effectiveness of the retrofitted test rig was analyzed by introducing various concentrations of contaminants in an oil medium that usually leads to a corrosive working environment. The results indicate that the retrofitted test rig can effectively monitor the in situ tribological performance of the oil in a controlled dynamic corrosive environment. It is a useful method to understand the wear-corrosion synergies for further experimental work, and to develop accurate predictive lifecycle assessment and prognostic models. The application of this system is expected to have economic benefits and help reduce the ecological oil waste footprint.
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Amorim PM, Ferraria AM, Colaço R, Branco LC, Saramago B. Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces. Beilstein J Nanotechnol 2017; 8:1961-1971. [PMID: 29046844 PMCID: PMC5629412 DOI: 10.3762/bjnano.8.197] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 08/31/2017] [Indexed: 06/02/2023]
Abstract
In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS), the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs) as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG) to lubricate Si surfaces. The friction coefficients were measured in a nanotribometer. The viscosity of the PEG + IL mixtures as well as their contact angles on the Si surface were measured. The topography and chemical composition of the substrates surfaces were determined with atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. Due to the hygroscopic properties of PEG, the first step was to assess the effect of the presence of water. Then, a series of ILs based on the cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-ethyl-3-vinylimidazolium [EVIM], 1-(2-hydroxyethyl)-3-methylimidazolium [C2OHMIM] and 1-allyl-3-methylimidazolium [AMIM] combined with the anions dicyanamide [DCA], trifluoromethanesulfonate [TfO], and ethylsulfate [EtSO4] were added to dry PEG. All additives (2 wt %) led to a decrease in friction coefficient as well as an increase in viscosity (with the exception of [AMIM][TfO]) and improved the Si wettability. The additives based on the anion [EtSO4] exhibited the most promising tribological behavior, which was attributed to the strong interaction with the Si surface ensuring the formation of a stable surface layer, which hinders the contact between the sliding surfaces.
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Affiliation(s)
- Patrícia M Amorim
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- LAQV-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal
| | - Ana M Ferraria
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Rogério Colaço
- IDMEC-Instituto de Engenharia Mecânica, Departamento de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Luís C Branco
- LAQV-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal
| | - Benilde Saramago
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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Rauf S, Jamil N, Tariq SA, Khan M, Kausar M, Kaya Y. Progress in modification of sunflower oil to expand its industrial value. J Sci Food Agric 2017; 97:1997-2006. [PMID: 28093767 DOI: 10.1002/jsfa.8214] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/09/2017] [Accepted: 01/11/2017] [Indexed: 05/20/2023]
Abstract
Increasing the sunflower seed oil content as well as improving its quality makes it compatible for industrial demands. This is an important breeding objective of sunflower which increases its market value and ensures high returns for the producers. The present review focuses on determining the progress of improving sunflower seed oil content and modifying its quality by empirical and advanced molecular breeding methods. It is known that the sunflower oil content and quality have been altered through empirical selection methods and mutation breeding programmes in various parts of the world. Further improvement in seed oil content and its components (such as phytosterols, tocopherols and modified fatty acid profile) has been slowed down due to low genetic variation in elite germplasm and complex of hereditary traits. Introgression from wild species can be carried out to modify the fatty acids profile and tocopherol contents with linkage drags. Different transgenes introduced through biotechnological methods may produce novel long-chain fatty acids within sunflower oil. Bio-engineering of sunflower oil could allow it to be used in diverse industrial products such as bio-diesel or bio-plastics. These results showed that past and current trends of modifying sunflower oil quality are essential for its further expansion as an oilseed crop. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Saeed Rauf
- Department of Plant Breeding & Genetics, University College of Agriculture, University of Sargodha, Pakistan
| | - Nazia Jamil
- Department of Microbiology and Molecular Genetics University of the Punjab, Quaid-e-Campus, Lahore, Pakistan
| | - Sultan Ali Tariq
- National Agriculture Research Institute, Murre Road, Islamabad, Pakistan
| | - Maria Khan
- Department of Plant Breeding & Genetics, University College of Agriculture, University of Sargodha, Pakistan
| | - Maria Kausar
- Department of Plant Breeding & Genetics, University College of Agriculture, University of Sargodha, Pakistan
| | - Yalcin Kaya
- Department of Genetic and Bioengineering, Engineering Faculty, Trakya University, Edirne, Turkey
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Lee M, Sandfort T, Collier K, Lane T, Reddy V. Breakage is the norm: use of condoms and lubrication in anal sex among Black South African men who have sex with men. Cult Health Sex 2017; 19:501-514. [PMID: 27737625 PMCID: PMC5340618 DOI: 10.1080/13691058.2016.1239134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper explores condom use and lubrication practices among Black men who have sex with men in South African townships. Results are from 81 in-depth individual interviews conducted among a purposive sample from four townships surrounding Pretoria as part of a larger qualitative study. Awareness that condoms should be used to have safer anal sex was ubiquitous. Fewer men reported that lubricants should be used to facilitate anal intercourse. Partner pressure and partner distrust were the most common barriers cited for not using condoms and lubricants. Knowledge about condom-lubricant compatibility was rare. Condom problems were a norm, with widespread expectations of condom failure. Men's subjectivities - their perceptions of and preferences for specific brands, types and flavours of condoms and lubricants - influenced engagement with such safer-sex technologies. However, what was available in these settings was often neither what men needed nor preferred. Findings show the need to enhance access to appropriate and comprehensive: safer-sex supplies, health services and health education, and underline the importance of efforts to develop targeted programmes relevant to experiences of men who have sex with men in the South African context.
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Affiliation(s)
- Matthew Lee
- HIV Center for Clinical and Behavioral Studies, Department of Psychiatry, Columbia University and New York State Psychiatric Institute, New York, New York, USA
| | - Theo Sandfort
- HIV Center for Clinical and Behavioral Studies, Department of Psychiatry, Columbia University and New York State Psychiatric Institute, New York, New York, USA
| | - Kate Collier
- HIV Center for Clinical and Behavioral Studies, Department of Psychiatry, Columbia University and New York State Psychiatric Institute, New York, New York, USA
| | - Tim Lane
- Center for AIDS Prevention Studies, University of California San Francisco, California, USA
| | - Vasu Reddy
- Faculty of Humanities, University of Pretoria, Pretoria, South Africa
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Curtis CK, Marek A, Smirnov AI, Krim J. A comparative study of the nanoscale and macroscale tribological attributes of alumina and stainless steel surfaces immersed in aqueous suspensions of positively or negatively charged nanodiamonds. Beilstein J Nanotechnol 2017; 8:2045-2059. [PMID: 29046852 PMCID: PMC5629417 DOI: 10.3762/bjnano.8.205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 09/05/2017] [Indexed: 05/14/2023]
Abstract
This article reports a comparative study of the nanoscale and macroscale tribological attributes of alumina and stainless steel surfaces immersed in aqueous suspensions of positively (hydroxylated) or negatively (carboxylated) charged nanodiamonds (ND). Immersion in -ND suspensions resulted in a decrease in the macroscopic friction coefficients to values in the range 0.05-0.1 for both stainless steel and alumina, while +ND suspensions yielded an increase in friction for stainless steel contacts but little to no increase for alumina contacts. Quartz crystal microbalance (QCM), atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurements were employed to assess nanoparticle uptake, surface polishing, and resistance to solid-liquid interfacial shear motion. The QCM studies revealed abrupt changes to the surfaces of both alumina and stainless steel upon injection of -ND into the surrounding water environment that are consistent with strong attachment of NDs and/or chemical changes to the surfaces. AFM images of the surfaces indicated slight increases in the surface roughness upon an exposure to both +ND and -ND suspensions. A suggested mechanism for these observations is that carboxylated -NDs from aqueous suspensions are forming robust lubricious deposits on stainless and alumina surfaces that enable gliding of the surfaces through the -ND suspensions with relatively low resistance to shear. In contrast, +ND suspensions are failing to improve tribological performance for either of the surfaces and may have abraded existing protective boundary layers in the case of stainless steel contacts. This study therefore reveals atomic scale details associated with systems that exhibit starkly different macroscale tribological properties, enabling future efforts to predict and design complex lubricant interfaces.
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Affiliation(s)
- Colin K Curtis
- Department of Physics, North Carolina State University, Raleigh, NC 27695, USA
| | - Antonin Marek
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Jacqueline Krim
- Department of Physics, North Carolina State University, Raleigh, NC 27695, USA
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Gonzalez Rodriguez P, Yuan H, van den Nieuwenhuizen KJH, Lette W, Schipper DJ, Ten Elshof JE. Hybrid n-Alkylamine Intercalated Layered Titanates for Solid Lubrication. ACS Appl Mater Interfaces 2016; 8:28926-28934. [PMID: 27715000 DOI: 10.1021/acsami.6b12716] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The intercalation of different primary n-alkylamines in the structure of a layered titanate of the lepidocrocite type (H1.07Ti1.73O4) for application in high-temperature solid lubrication is reported. The intercalation process of the amines was explored by means of in situ small-angle X-ray scattering (SAXS), with variations in alkyl chain length (3-12 carbon atoms) and the amine/titanate ratio. The intercalation process was found to be completed within 5 min after mixing of the precursors in water at 80 °C. The topotactic transformation of the layered titanate is driven by an acid-base reaction. The thermal degradation of the modified titanates was investigated by thermogravimetric analysis (TGA), and the chemical changes were investigated by temperature-dependent infrared spectroscopy (DRIFTS). The coefficient of friction of the lubricants was assessed by means of high-temperature pin-on-disc experiments up to 580 °C. The intercalation of amine rendered a deformable layered ceramic upon heating. It was found that the hydrocarbon chain length exerts an influence on the mechanical properties of the titanates, resulting in lower friction forces for lubricants with longer intercalated amine molecules. Films of solid lubricants with longer amine chain lengths showed coefficients of friction as low as 0.01, lower than that of the state-of-the-art material graphite.
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Nie H, Xu W, Ren J, Taylor LS, Marsac PJ, John CT, Byrn SR. Impact of Metallic Stearates on Disproportionation of Hydrochloride Salts of Weak Bases in Solid-State Formulations. Mol Pharm 2016; 13:3541-3552. [PMID: 27542728 DOI: 10.1021/acs.molpharmaceut.6b00630] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Excipient-induced salt disproportionation (conversion from salt form to free form) in the solid state during storage or manufacturing is a severe formulation issue that can negatively influence product performance. However, the role of excipient properties on salt disproportionation and mechanisms of proton transfer between salt and excipients are still unclear. Moreover, knowledge about the formation of disproportionation products and the consequent impact of these reactions products on the disproportionation process is still inadequate. In the present study, three commonly used lubricants (sodium stearate, calcium stearate, and magnesium stearate) were mixed with a hydrochloride salt as binary mixtures to examine their different capabilities for inducing salt disproportionation at a stressed storage condition (40 °C/65% RH). The overall objective of this research is to explore factors influencing the kinetics and extent of disproportionation including surface area, alkalinity, hygroscopicity, formation of new species, etc. In addition, we also aim to clarify the reaction mechanism and proton transfer between the model salt and stearates to provide insight into the in situ formed reaction products. We found that the properties of stearates significantly affect the disproportionation process in the initial stage of storage, while properties of the reaction products negatively affect the hygroscopicity of the powder mixture promoting disproportionation during longer-term storage. In addition, lubrication difference among three stearates was evaluated by performing compaction studies. The findings of this study provide an improved understanding of the proton transfer mechanism between the ionized form of an active pharmaceutical ingredient and excipients in solid dosage forms. It also provides pragmatic information for formulation scientists to select appropriate lubricants and other excipients, and to design robust formulations.
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Affiliation(s)
- Haichen Nie
- Department of Industrial and Physical Pharmacy, Purdue University , 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Wei Xu
- Preformulation Sciences, Merck & Co., Inc. , 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Jie Ren
- Oral Formulation Science, Merck & Co., Inc. , 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Lynne S Taylor
- Department of Industrial and Physical Pharmacy, Purdue University , 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Patrick J Marsac
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Christopher T John
- Discovery Pharmaceutical Science, Merck & Co., Inc. , 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Stephen R Byrn
- Department of Industrial and Physical Pharmacy, Purdue University , 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
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Ewen JP, Gattinoni C, Thakkar FM, Morgan N, Spikes HA, Dini D. A Comparison of Classical Force-Fields for Molecular Dynamics Simulations of Lubricants. Materials (Basel) 2016; 9:ma9080651. [PMID: 28773773 PMCID: PMC5509262 DOI: 10.3390/ma9080651] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 07/20/2016] [Accepted: 07/28/2016] [Indexed: 01/26/2023]
Abstract
For the successful development and application of lubricants, a full understanding of their complex nanoscale behavior under a wide range of external conditions is required, but this is difficult to obtain experimentally. Nonequilibrium molecular dynamics (NEMD) simulations can be used to yield unique insights into the atomic-scale structure and friction of lubricants and additives; however, the accuracy of the results depend on the chosen force-field. In this study, we demonstrate that the use of an accurate, all-atom force-field is critical in order to; (i) accurately predict important properties of long-chain, linear molecules; and (ii) reproduce experimental friction behavior of multi-component tribological systems. In particular, we focus on n-hexadecane, an important model lubricant with a wide range of industrial applications. Moreover, simulating conditions common in tribological systems, i.e., high temperatures and pressures (HTHP), allows the limits of the selected force-fields to be tested. In the first section, a large number of united-atom and all-atom force-fields are benchmarked in terms of their density and viscosity prediction accuracy of n-hexadecane using equilibrium molecular dynamics (EMD) simulations at ambient and HTHP conditions. Whilst united-atom force-fields accurately reproduce experimental density, the viscosity is significantly under-predicted compared to all-atom force-fields and experiments. Moreover, some all-atom force-fields yield elevated melting points, leading to significant overestimation of both the density and viscosity. In the second section, the most accurate united-atom and all-atom force-field are compared in confined NEMD simulations which probe the structure and friction of stearic acid adsorbed on iron oxide and separated by a thin layer of n-hexadecane. The united-atom force-field provides an accurate representation of the structure of the confined stearic acid film; however, friction coefficients are consistently under-predicted and the friction-coverage and friction-velocity behavior deviates from that observed using all-atom force-fields and experimentally. This has important implications regarding force-field selection for NEMD simulations of systems containing long-chain, linear molecules; specifically, it is recommended that accurate all-atom potentials, such as L-OPLS-AA, are employed.
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Affiliation(s)
- James P Ewen
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK.
| | - Chiara Gattinoni
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK.
| | - Foram M Thakkar
- Shell India Markets Private Limited, 8B RMZ Centennial Building, Kundanahalli Main Road, Bangalore 560048, India.
| | - Neal Morgan
- Shell Global Solutions UK Ltd., Brabazon House, Manchester M22 0RR, UK.
| | - Hugh A Spikes
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK.
| | - Daniele Dini
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK.
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Mazzo A, Pecci GL, Fumincelli L, Neves RC, Dos Santos RCR, Cassini MF, Tucci S. Intermittent urethral catheterisation: the reality of the lubricants and catheters in the clinical practice of a Brazilian service. J Clin Nurs 2016; 25:3382-3390. [PMID: 27378618 DOI: 10.1111/jocn.13466] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2016] [Indexed: 11/29/2022]
Abstract
AIMS AND OBJECTIVES To identify how catheters and lubricants have been used among patients using intermittent urinary catheterisation in rehabilitation. BACKGROUND The clean intermittent urinary catheterisation technique is an invasive procedure can cause discomfort, pain and urethral traumas. The use of lubricants and lubricated urinary catheters reduces the friction between the catheter and the urethral mucosa, minimising the risks. DESIGN A descriptive exploratory design was used. METHODS Quantitative and descriptive study developed at a rehabilitation centre of a University Hospital in the interior of the state of São Paulo, Brazil, at the Intermittent Urinary Catheterisation Outpatient Clinic, between June 2012-December 2014. After ethical approval, the data were collected through an interview with the support of a semistructured questionnaire, held during the nursing consultation. Among the users, patients using intermittent urinary catheterisation were interviewed, over 18 years of age and minors younger than eight years accompanied. Descriptive statistical analysis was applied. RESULTS Most of 214 (100·0%) patients were interviewed were male, single, young adults and with a primary medical diagnosis of bone marrow injury and myelomeningocele. Most patients perform the urinary catheterisation between four and six times per day. For the procedure, the majority uses polyethylene (polyvinyl chloride) catheter and, as a lubricant, 2·0% lidocaine hydrochloride on the catheter itself. Many mention lack of sensitivity when passing the catheter. CONCLUSION In the study sample, a risk of urethral traumas was evidenced, related to the inappropriate use of catheters and lubricants. For the patients' safety, the professionals need to acknowledge the importance of the appropriate use of lubricants and lubricated catheters to implement evidence-based practices that mobilise public policies. RELEVANCE TO CLINICAL PRACTICE The use of evidences demonstrates that the appropriate use of lubricants for intermittent urinary catheterisation is fundamental for patient safety and the performance of the best practices.
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Affiliation(s)
- Alessandra Mazzo
- General and Specialized Nursing Department, EERP-USP, Ribeirão Preto, Brazil.
| | - Gabriel Luiz Pecci
- University of São Paulo at Ribeirão Preto College of Nursing, WHO Collaborating Centre for Nursing Research (EERP-USP), Ribeirão Preto, Brazil
| | - Laís Fumincelli
- Fundamental Nursing Graduate Program, EERP-USP, Ribeirão Preto, Brazil
| | | | | | - Marcelo Ferreira Cassini
- Division of Urology, Department of Surgery and Anatomy, Ribeirão Preto Faculty of Medicine, University of São Paulo (FMRP-USP), Ribeirão Preto, Brazil
| | - Silvio Tucci
- Department of Surgery and Anatomy, FMRP-USP, Ribeirão Preto, Brazil.,Division of Urology, FMRP-USP, Brazil
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Balakrishnan M, Sacia ER, Sreekumar S, Gunbas G, Gokhale AA, Scown CD, Toste FD, Bell AT. Novel pathways for fuels and lubricants from biomass optimized using life-cycle greenhouse gas assessment. Proc Natl Acad Sci U S A 2015; 112:7645-9. [PMID: 26056307 DOI: 10.1073/pnas.1508274112] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Decarbonizing the transportation sector is critical to achieving global climate change mitigation. Although biofuels will play an important role in conventional gasoline and diesel applications, bioderived solutions are particularly important in jet fuels and lubricants, for which no other viable renewable alternatives exist. Producing compounds for jet fuel and lubricant base oil applications often requires upgrading fermentation products, such as alcohols and ketones, to reach the appropriate molecular-weight range. Ketones possess both electrophilic and nucleophilic functionality, which allows them to be used as building blocks similar to alkenes and aromatics in a petroleum refining complex. Here, we develop a method for selectively upgrading biomass-derived alkyl methyl ketones with >95% yields into trimer condensates, which can then be hydrodeoxygenated in near-quantitative yields to give a new class of cycloalkane compounds. The basic chemistry developed here can be tailored for aviation fuels as well as lubricants by changing the production strategy. We also demonstrate that a sugarcane biorefinery could use natural synergies between various routes to produce a mixture of lubricant base oils and jet fuels that achieve net life-cycle greenhouse gas savings of up to 80%.
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Uğurlu T, Halaçoğlu MD. Effects of hexagonal boron nitride on dry compression mixture of Avicel DG and Starch 1500. Pharm Dev Technol 2015; 21:415-27. [PMID: 25716058 DOI: 10.3109/10837450.2015.1016617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The objective of this study was to investigate the lubrication properties of hexagonal boron nitride (HBN) on a (1:1) binary mixture of Avicel DG and Starch 1500 after using the dry granulation-slugging method and compare it with conventional lubricants, such as magnesium stearate (MGST), glyceryl behenate (COMP) and stearic acid (STAC). MGST is one of the most commonly used lubricants in the pharmaceutical industry. However, it has several adverse effects on tablet properties. In our current study, we employed various methods to eradicate the work hardening phenomenon in dry granulation, and used HBN as a new lubricant to overcome the adverse effects of other lubricants on tablet properties. HBN was found to be as effective as MGST and did not show any significant adverse effects on the crushing strength or work hardening. From the scanning electron microscope (SEM) images, it was concluded that HBN distributed better than MGST. As well as showing better distribution, HBN's effect on disintegration was the least pronounced. Semi-quantitative weight percent distribution of B and N elements in the tablets was obtained using EDS (energy dispersive spectroscopy). Based on atomic force microscope (AFM) surface roughness images, formulations prepared with 1% HBN showed better plastic character than those prepared with MGST.
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Affiliation(s)
- Timuçin Uğurlu
- a Department of Pharmaceutical Technology, Faculty of Pharmacy , Marmara University , Haydarpaşa , Istanbul , Turkey
| | - Mekin Doğa Halaçoğlu
- a Department of Pharmaceutical Technology, Faculty of Pharmacy , Marmara University , Haydarpaşa , Istanbul , Turkey
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Halaçoğlu MD, Uğurlu T. Compression parameters of hexagonal boron nitride on direct compression mixture of microcrystalline cellulose and modified starch. Pharm Dev Technol 2014; 20:747-54. [PMID: 24841191 DOI: 10.3109/10837450.2014.920354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The objective of this study was to investigate the effects of conventional lubricants including a new candidate lubricant "hexagonal boron nitride (HBN)" on direct compression powders. Lubricants such as magnesium stearate (MGST), glyceryl behenate, stearic acid, talc and polyethylene glycol6000 were studied and tablets were manufactured on a single station instrumented tablet press. This study comprised the continuation of our previous one, so mixture of microcrystalline cellulose and modified starch was used as a master formula to evaluate effects of lubricants on pharmaceutical excipients that undergo complete plastic deformation without any fragmentation under compression pressure. Bulk and tapped densities, and Carr's index parameters were calculated for powders. Tensile strength, cohesion index, lower punch ejection force and lubricant effectiveness values were investigated for tablets. The deformation mechanisms of tablets were studied during compression from the Heckel plots with or without lubricant. MGST was found to be the most effective lubricant and HBN was found very close to it. HBN did not show a significant negative effect on the crushing strength and disintegration time of the tablets when we compared with MGST. Based on the Heckel plots at the level of 1%, formulation prepared with HBN showed the most pronounced plastic character.
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Affiliation(s)
- Mekin Doğa Halaçoğlu
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Marmara University , Haydarpasa, Istanbul , Turkey
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Sandhu RS, Wong TH, Kling CA, Chohan KR. In vitro effects of coital lubricants and synthetic and natural oils on sperm motility. Fertil Steril 2014; 101:941-4. [PMID: 24462060 DOI: 10.1016/j.fertnstert.2013.12.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 12/04/2013] [Accepted: 12/16/2013] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To evaluate the effects of coital lubricants and oils on sperm motility. DESIGN Comparative prospective in vitro study. SETTING University Andrology laboratory. PATIENT(S) Twenty-two normozoospermic donors. INTERVENTION(S) Semen samples were incubated in modified human tubal fluid (mHTF) control and in 10% Pre-Seed, Astroglide, and KY products (Sensitive, Warming, and Tingling) and baby, canola, sesame, and mustard oils. Total and progressive sperm motility was evaluated before and at 5, 30, and 60 minutes of incubation. MAIN OUTCOME MEASURE(S) Sperm motility. RESULT(S) Control samples exhibited no significant decrease in sperm motility. Pre-Seed showed a slight (∼4%) but significant drop in progressive motility after 30 minutes. Total and progressive sperm motility significantly declined under Astroglide, KY products (Sensitive, Warming, and Tingling) and sesame oil incubation. Canola oil significantly decreased total motility after 30 minutes and progressive motility after 5 minutes of incubation. Similarly, baby oil decreased total motility after 60 minutes and progressive motility after 5 minutes. After initial decline, total and progressive sperm motility under Pre-Seed and canola and baby oils remained high. Exposure to mustard oil caused persistent hyperactivation of sperm in each sample with no decrease in motility. CONCLUSION(S) Sesame oil and synthetic coital lubricants impaired sperm motility and may hamper fertility. Pre-Seed and canola, mustard, and baby oils showed no deleterious effect and may be considered sperm-friendly coital lubricants. Mustard oil exposure resulted in hyperactivation of sperm and needs to be studied further.
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Affiliation(s)
- Ranjit S Sandhu
- Andrology Laboratory, State University of New York Upstate Medical University, Syracuse, New York
| | - Timothy H Wong
- Andrology Laboratory, State University of New York Upstate Medical University, Syracuse, New York
| | - Crystal A Kling
- Andrology Laboratory, State University of New York Upstate Medical University, Syracuse, New York
| | - Kazim R Chohan
- Andrology Laboratory, State University of New York Upstate Medical University, Syracuse, New York.
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Geibel S. Condoms and condiments: compatibility and safety of personal lubricants and their use in Africa. J Int AIDS Soc 2013; 16:18531. [PMID: 23841994 PMCID: PMC3708353 DOI: 10.7448/ias.16.1.18531] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Revised: 05/06/2013] [Accepted: 06/06/2013] [Indexed: 11/08/2022] Open
Abstract
Previous research on the use of personal lubricants for sexual intercourse is limited and has primarily focused on condom compatibility and breakage, with only recent limited assessment of lubricant safety and possible epidemiologic implications. This article discusses the global evidence of lubricant compatibility with latex condoms and biological safety of lubricants, as well as documentation of lubricant use and current guidelines for HIV prevention programming in Africa. Data on lubricant compatibility with condoms are less available than commonly realized, and many lubricant products may not have been thoroughly tested for safety due to flexible regulatory environments. Recent laboratory and study findings from microbicides research also suggest that some water-based lubricants may have safety issues. Some African populations are using several types of lubricants, especially oil-based petroleum jellies, and receive little evidence-based guidance. More research is needed from the medical community to guide prevention programming.
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