1
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Weiand E, Koenig PH, Rodriguez-Ropero F, Roiter Y, Angioletti-Uberti S, Dini D, Ewen JP. Boundary Lubrication Performance of Polyelectrolyte-Surfactant Complexes on Biomimetic Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:7933-7946. [PMID: 38573738 PMCID: PMC11025133 DOI: 10.1021/acs.langmuir.3c03737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/20/2024] [Accepted: 03/20/2024] [Indexed: 04/05/2024]
Abstract
Aqueous mixtures of oppositely charged polyelectrolytes and surfactants are useful in many industrial applications, such as shampoos and hair conditioners. In this work, we investigate the friction between biomimetic hair surfaces in the presence of adsorbed complexes formed from cationic polyelectrolytes and anionic surfactants in an aqueous solution. We apply nonequilibrium molecular dynamics (NEMD) simulations using the coarse-grained MARTINI model. We first developed new MARTINI parameters for cationic guar gum (CGG), a functionalized, plant-derived polysaccharide. The complexation of CGG and the anionic surfactant sodium dodecyl sulfate (SDS) on virgin and chemically damaged biomimetic hair surfaces was studied using a sequential adsorption approach. We then carried out squeeze-out and sliding NEMD simulations to assess the boundary lubrication performance of the CGG-SDS complex compressed between two hair surfaces. At low pressure, we observe a synergistic friction behavior for the CGG-SDS complex, which gives lower shear stress than either pure CGG or SDS. Here, friction is dominated by viscous dissipation in an interfacial layer comprising SDS and water. At higher pressures, which are probably beyond those usually experienced during hair manipulation, SDS and water are squeezed out, and friction increases due to interdigitation. The outcomes of this work are expected to be beneficial to fine-tune and screen sustainable hair care formulations to provide low friction and therefore a smooth feel and reduced entanglement.
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Affiliation(s)
- Erik Weiand
- Department
of Mechanical Engineering, Imperial College
London, South Kensington Campus, London SW7 2AZ, U.K.
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - Peter H. Koenig
- Corporate
Functions Analytical and Data & Modeling Sciences, Mason Business
Center, The Procter and Gamble Company, Mason, Ohio 45040, United States
| | - Francisco Rodriguez-Ropero
- Corporate
Functions Analytical and Data & Modeling Sciences, Mason Business
Center, The Procter and Gamble Company, Mason, Ohio 45040, United States
| | - Yuri Roiter
- Corporate
Functions Analytical and Data & Modeling Sciences, Mason Business
Center, The Procter and Gamble Company, Mason, Ohio 45040, United States
| | - Stefano Angioletti-Uberti
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
- Department
of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - Daniele Dini
- Department
of Mechanical Engineering, Imperial College
London, South Kensington Campus, London SW7 2AZ, U.K.
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - James P. Ewen
- Department
of Mechanical Engineering, Imperial College
London, South Kensington Campus, London SW7 2AZ, U.K.
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
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2
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Chen X, Hu T, Wu W, Yi X, Li F, Zhang C. Tribological Behavior of Sulfonated Polyether Ether Ketone with Three Different Chemical Structures under Water Lubrication. Polymers (Basel) 2024; 16:998. [PMID: 38611256 PMCID: PMC11013479 DOI: 10.3390/polym16070998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 03/14/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
With the development of the shipbuilding industry, it is necessary to improve tribological properties of polyether ether ketone (PEEK) as a water-lubricated bearing material. In this study, the sulfonated PEEK (SPEEK) with three distinct chemical structures was synthesized through direct sulfonated polymerization, and high fault tolerance and a controllable sulfonation degree ensured the batch stability. The tribological and mechanical properties of SPEEK with varying side groups (methyl and tert-butyl) and rigid segments (biphenyl) were compared after sintering in a vacuum furnace. Compared to the as-made PEEK, as the highly electronegative sulfonic acid group enhanced the hydration lubrication, the friction coefficient and wear rate of SPEEK were significantly reduced by 30% and 50% at least without affecting the mechanical properties. And lower steric hindrance and entanglement between molecular chains were proposed to be partially responsible for the lowest friction behavior of SPEEK with methyl side groups, making it a promising and competitive option for water-lubricated bearings.
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Affiliation(s)
- Xiaozhi Chen
- School of Metallurgy, Northeastern University, Shenyang 110819, China;
| | - Tao Hu
- Engineering Center for Superlubricity, Jihua Laboratory, Foshan 528200, China; (T.H.); (W.W.); (C.Z.)
| | - Wei Wu
- Engineering Center for Superlubricity, Jihua Laboratory, Foshan 528200, China; (T.H.); (W.W.); (C.Z.)
| | - Xiaohong Yi
- Engineering Center for Superlubricity, Jihua Laboratory, Foshan 528200, China; (T.H.); (W.W.); (C.Z.)
| | - Fenghua Li
- School of Metallurgy, Northeastern University, Shenyang 110819, China;
| | - Chenhui Zhang
- Engineering Center for Superlubricity, Jihua Laboratory, Foshan 528200, China; (T.H.); (W.W.); (C.Z.)
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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3
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Stevens MC, Taylor NM, Guo X, Hussain H, Mahmoudi N, Cattoz BN, Leung AHM, Dowding PJ, Vincent B, Briscoe WH. Diblock bottlebrush polymer in a non-polar medium: Self-assembly, surface forces, and superlubricity. J Colloid Interface Sci 2024; 658:639-647. [PMID: 38134672 DOI: 10.1016/j.jcis.2023.12.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/08/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
Whilst bottlebrush polymers have been studied in aqueous media for their conjectured role in biolubrication, surface forces and friction mediated by bottlebrush polymers in non-polar media have not been previously reported. Here, small-angle neutron scattering (SANS) showed that a diblock bottlebrush copolymer (oligoethyleneglycol acrylate/ethylhexyl acrylate; OEGA/EHA) formed spherical core-shell aggregates in n-dodecane (a model oil) in the polymer concentration range 0.1-2.0 wt%, with a radius of gyration Rg ∼ 7 nm, comprising 40-65 polymer molecules per aggregate. The surface force apparatus (SFA) measurements revealed purely repulsive forces between surfaces bearing inhomogeneous polymer layers of thickness L ∼ 13-23 nm, attributed to adsorption of a mixture of polymer chains and surface-deformed micelles. Despite the surface inhomogeneity, the polymer layers could mediate effective lubrication, demonstrating superlubricity with the friction coefficient as low as µ ∼ 0.003. The analysis of velocity-dependence of friction using the Eyring model shed light on the mechanism of the frictional process. That is, the friction mediation was consistent with the presence of nanoscopic surface aggregates, with possible contributions from a gel-like network formed by the polymer chains on the surface. These unprecedented results, correlating self-assembled polymer micelle structure with the surface forces and friction the polymer layers mediate, highlight the potential of polymers with the diblock bottlebrush architecture widespread in biological living systems, in tailoring desired surface interactions in non-polar media.
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Affiliation(s)
- Michael C Stevens
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Nicholas M Taylor
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK; Syngenta, Jealott's Hill International Research Centre, Bracknell RG42 6EY, UK
| | - Xueying Guo
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Hadeel Hussain
- Diamond Light Source Ltd, I07 Beamline, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Najet Mahmoudi
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX, UK
| | - Beatrice N Cattoz
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Alice H M Leung
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Peter J Dowding
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Brian Vincent
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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Zhang T, Gai K, Li R, Liang Y, Li L, Chen J, Nie M. Robust and self-lubricating polyvinyl alcohol tubes with a mucosa-like hierarchical architecture for endotracheal intubation. J Mater Chem B 2024; 12:1330-1343. [PMID: 38230443 DOI: 10.1039/d3tb02402d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Mechanical mismatch between interventional intubation tubes and human tissues often triggers inevitable friction and causes secondary injury to patients during interventional therapy. Herein, we propose a fabrication strategy of a self-lubricating polyvinyl alcohol (PVA) tube by industrial extrusion technology followed by simple infiltration with water. First, biocompatible glycerin was introduced to weaken the intrinsic hydrogen interaction of PVA by new molecular complexation, broadening the gap between the melting and decomposition temperatures and enabling the stable extrusion of the PVA tube. Subsequently, the as-prepared PVA tube was infiltrated with an aqueous solution to construct a strong hydrogen bonding network between PVA and water molecules, forming a soft hydration layer similar to the upper epithelium layer of mucosa. Benefiting from the solid and liquid properties of the hydration layer as well as the small proportion relative to the whole, the infiltrated PVA tube exhibited excellent hydration lubrication behavior and robust mechanical property. The friction coefficient, tensile strength and elongation at break were measured to be 0.05, 26.2 MPa and 654%, respectively, surpassing the values of 0.5, 16.4 MPa and 240% observed in a commercial polyvinyl chloride tube. In vitro, the PVA intubation tube demonstrated significant biocompatibility, and short-term exposure exhibited minimal impacts on the morphology and proliferation of L929 cells. Ultimately, the potential of the infiltrated PVA tube for interventional intubation was demonstrated successfully using an in vivo rabbit model, providing a new idea for the follow-up development of interventional intubation tubes.
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Affiliation(s)
- Tongrui Zhang
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
| | - Kuo Gai
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
| | - Ruyi Li
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
| | - Yi Liang
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
| | - Li Li
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
| | - Junyu Chen
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
| | - Min Nie
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
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5
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Taylor NM, Pilkington GA, Snow T, Dowding PJ, Cattoz BN, Schwarz AD, Bikondoa O, Vincent B, Briscoe WH. Surface forces and friction between Langmuir-Blodgett polymer layers in a nonpolar solvent. J Colloid Interface Sci 2024; 653:1432-1443. [PMID: 37804612 DOI: 10.1016/j.jcis.2023.09.146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/28/2023] [Accepted: 09/24/2023] [Indexed: 10/09/2023]
Abstract
Optimization of boundary lubrication by tuning the confined molecular structures formed by surface-active additives such as surfactants and polymers is of key importance to improving energy efficiency in mechanical processes. Here, using the surface forces apparatus (SFA), we have directly measured the normal and shear forces between surface layers of a functionalised olefin copolymer (FOCP) in n-dodecane, deposited onto mica using the Langmuir-Blodgett (LB) technique. The FOCP has an olefin backbone decorated with a statistical distribution of polar-aromatic groups, with a structure that we term as "centipede". The effect of lateral confinement, characterised by the surface pressure, Πdep, at the air-water interface at which the LB films are transferred, was examined. Normal force profiles revealed that the thickness of the LB films increased significantly with Πdep, with the film thickness (t > 20 nm) inferring a multi-layered film structure, consistent with the interfacial characterisation results from synchrotron X-ray reflectivity (XRR) measurements. The coefficient of friction, µ, between the LB films spanned two orders of magnitude from superlubricity (µ ∼ 0.002) to much higher friction (µ > 0.1) depending nonlinearly on Πdep, with the lowest friction observed at the intermediate Πdep. Molecular arrangement upon LB compression leads to the multilayer film with a structure akin to an interfacial gel, with transient crosslinking facilitated by the intra- and inter-molecular interactions between the functional groups. We attribute the differences in frictional behaviour to the different prevalence of the FOCP functional groups at the lubricating interface, which depends sensitively on the degree of compression at the air-water interface prior to the LB deposition. The LB films remain intact after repeated compression (up to pressures of 10 MPa) and shear cycles, indicating strong surface anchorage and structural robustness as a load-bearing and shear-mediating boundary layer. These unprecedented results from the friction measurements between LB films of a statistical copolymer in oil point towards new strategies for tailoring macromolecular architecture for mediating efficient energy dissipation in oil-based tribological applications.
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Affiliation(s)
- Nicholas M Taylor
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Georgia A Pilkington
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Tim Snow
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Peter J Dowding
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Beatrice N Cattoz
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Andrew D Schwarz
- Infineum UK Ltd, Milton Hill Business and Technology Centre, Abingdon, Oxon OX13 6BB, UK
| | - Oier Bikondoa
- XMaS, The UK CRG Beamline, European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38043 Grenoble, France; Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Brian Vincent
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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6
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Mielke S, Sorkin R, Klein J. Effect of cholesterol on the mechanical stability of gel-phase phospholipid bilayers studied by AFM force spectroscopy. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:77. [PMID: 37672138 DOI: 10.1140/epje/s10189-023-00338-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/24/2023] [Indexed: 09/07/2023]
Abstract
The remarkably low sliding friction of articular cartilage in the major joints such as hips and knees, which is crucial for its homeostasis and joint health, has been attributed to lipid bilayers forming lubricious boundary layers at its surface. The robustness of such layers, and thus their lubrication efficiency at joint pressures, depends on the lipids forming them, including cholesterol which is a ubiquitous component, and which may act to strengthen of weaken the bilayer. In this work, a systematic study using an atomic force microscope (AFM) was carried out to understand the effect of cholesterol on the nanomechanical stability of two saturated phospholipids, DSPC (1,2-distearoyl-sn-glycero-3-phosphatidlycholine) and DPPC (1,2-dipalmitoyl-sn-glycero- phosphatidylcholine), that differ in acyl chain lengths. Measurements were carried out both in water and in phosphate buffer solution (PBS). The nanomechanical stability of the lipid bilayers was quantitatively evaluated by measuring the breakthrough force needed to puncture the bilayer by the AFM tip. The molar fractions of cholesterol incorporated in the bilayers were 10% and 40%. We found that for both DSPC and DPPC, cholesterol significantly decreases the mechanical stability of the bilayers in solid-ordered (SO) phase. In accordance with the literature, the strengthening effect of salt on the lipid bilayers was also observed. For DPPC with 10 mol % cholesterol, the effect of tip properties and the experimental procedure parameters on the breakthrough forces were also studied. Tip radius (2-42 nm), material (Si, Si3N4, Au) and loading rate (40-1000 nm/s) were varied systematically. The values of the breakthrough forces measured were not significantly affected by any of these parameters, showing that the weakening effect of cholesterol does not result from such changes in experimental conditions. As we have previously demonstrated that mechanical robustness improves the tribological performance of lipid layers, this study helps to shed light on the mechanism of physiological lubrication. Nanoindentation of SDPC bilayers.
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Affiliation(s)
- Salomé Mielke
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Raya Sorkin
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel.
| | - Jacob Klein
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 76100, Rehovot, Israel.
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7
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Beschorner KE, Randolph AB. Friction performance of resilient flooring under contaminant conditions relevant to healthcare settings. APPLIED ERGONOMICS 2023; 108:103960. [PMID: 36610081 DOI: 10.1016/j.apergo.2022.103960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/12/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
Flooring is among the factors known to influence slip and fall risk. Slips are common in the healthcare industry, where resilient flooring is prevalent. This study assessed coefficient of friction (COF) across resilient flooring products specific to conditions relevant to healthcare. The COF for eleven resilient flooring surfaces were tested in their dry condition and under six contaminant conditions. Data was analyzed using ANOVA and principal component analysis. The COF was strongly influenced by the contaminant condition (p < 0.001) with hand sanitizer and canola oil having the lowest COF values. COF was also influenced by the flooring product (p < 0.001) although to a lesser extent than the contaminant condition. The contaminants differentially affected the friction performance across the flooring products (interaction effect p < 0.001). These effects were described by the first two principal components. This study reveals high slipping potential for certain contaminants on resilient flooring and that flooring influences friction performance in contaminant-specific ways.
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Affiliation(s)
- Kurt E Beschorner
- Department of Bioengineering, University of Pittsburgh, 3700 O'Hara St., Pittsburgh, PA, 15213, USA.
| | - Anna B Randolph
- Department of Bioengineering, University of Pittsburgh, 3700 O'Hara St., Pittsburgh, PA, 15213, USA
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Cheng B, Li C, Zhang B, Liu J, Lu Z, Zhang P, Wei H, Yu Y. Customizable Low-Friction Tough Hydrogels for Potential Cartilage Tissue Engineering by a Rapid Orthogonal Photoreactive 3D-Printing Design. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 36893430 DOI: 10.1021/acsami.3c00065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Hydrogels have demonstrated wide applications in tissue engineering, but it is still challenging to develop strong, customizable, low-friction artificial scaffolds. Here, we report a rapid orthogonal photoreactive 3D-printing (ROP3P) strategy to achieve the design of high-performance hydrogels in tens of minutes. The orthogonal ruthenium chemistry enables the formation of multinetworks in hydrogels via phenol-coupling reaction and traditional radical polymerization. Further Ca2+-cross-linking treatment greatly improves their mechanical properties (6.4 MPa at a critical strain of 300%) and toughness (10.85 MJ m-3). The tribological investigation reveals that the high elastic moduli of the as-prepared hydrogels improve their lubrication (∼0.02) and wear-resistance performances. These hydrogels are biocompatible and nontoxic and promote bone marrow mesenchymal stem cell adhesion and propagation. The introduction of 1-hydroxy-3-(acryloylamino)-1,1-propanediylbisphosphonic acid units can greatly enhance their antibacterial property to kill typical Escherichia coli and Staphylococcus aureus. Moreover, the rapid ROP3P can achieve hydrogel preparation in several seconds and is readily compatible with making artificial meniscus scaffolds. The printed meniscus-like materials are mechanically stable and can maintain their shape under long-term gliding tests. It is anticipated that these high-performance customizable low-friction tough hydrogels and the highly efficient ROP3P strategy could promote further development and practical applications of hydrogels in biomimetic tissue engineering, materials chemistry, bioelectronics, and so on.
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Affiliation(s)
- Bo Cheng
- School of Mechanical Engineering, North University of China, Taiyuan 030051, China
| | - Chengpeng Li
- School of Mechanical Engineering, North University of China, Taiyuan 030051, China
| | - Bo Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610017, China
| | - Jupen Liu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Zhe Lu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Ping Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - Hongqiu Wei
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
| | - You Yu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China
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9
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Ikarashi T, Nakayama K, Nakajima N, Miyata K, Miyazawa K, Fukuma T. Visualizing Molecular-Scale Adsorption Structures of Anti-freezing Surfactants on Sapphire (0001) Surfaces at Different Concentrations by 3D Scanning Force Microscopy. ACS APPLIED MATERIALS & INTERFACES 2022; 14:44947-44957. [PMID: 36126145 DOI: 10.1021/acsami.2c10475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Anti-freezing surfactants form an adsorption layer at the solid-water interface to inhibit the nucleation and growth of ice. However, this mechanism has not been elucidated at the molecular scale because of the difficulties in visualizing such adsorption structures. In this study, we overcome this limitation by directly visualizing the three-dimensional (3D) adsorption structures of anti-freezing surfactants, hexadecyltrimethylammonium bromide (C16TABs), on sapphire (0001) surfaces through 3D scanning force microscopy. We present molecularly resolved two-dimensional/3D images of the adsorption structures in solutions of 1, 10, and 100 ppm. At 1 ppm, the molecules form a monolayer with a flat-lying configuration. At 10 ppm, the molecular orientation is closer to the upright configuration, with a relatively large tilt angle. At 100 ppm, the molecules form a bilayer with almost upright configurations, providing excellent screening of the sapphire surface from water. Owing to the steric and electrostatic repulsion between adjacent molecular head groups, the surface of the bilayer exhibits relatively large fluctuations, inhibiting the formation of stable ice-like structures. The understanding of molecular-level mechanisms provides important guidelines for improving the design of anti-freezing surfactants for practical applications such as car coolants.
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Affiliation(s)
- Takahiko Ikarashi
- Division of Nano Life Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
| | - Kyosuke Nakayama
- Division of Electrical Engineering and Computer Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
| | - Naoki Nakajima
- Division of Electrical Engineering and Computer Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
| | - Kazuki Miyata
- Division of Nano Life Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Division of Electrical Engineering and Computer Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Division of Frontier Engineering, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
| | - Keisuke Miyazawa
- Division of Electrical Engineering and Computer Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Division of Frontier Engineering, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
| | - Takeshi Fukuma
- Division of Nano Life Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Division of Electrical Engineering and Computer Science, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
- Division of Frontier Engineering, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa, Japan
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10
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Lin W, Kampf N, Klein J. Neutral polyphosphocholine-modified liposomes as boundary superlubricants. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129218] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Phospholipids and Hyaluronan: From Molecular Interactions to Nano- and Macroscale Friction. COLLOIDS AND INTERFACES 2022. [DOI: 10.3390/colloids6030038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Phospholipids and hyaluronan are two key biomolecules that contribute to the excellent lubrication of articular joints. Phospholipids alone and in combination with hyaluronan have also displayed low friction forces on smooth surfaces in micro- and nanosized tribological contacts. In an effort to develop aqueous-based lubrication systems, it is highly relevant to explore if these types of molecules also are able to provide efficient lubrication of macroscopic tribological contacts involving surfaces with roughness larger than the thickness of the lubricating layer. To this end, we investigated the lubrication performance of hyaluronan, the phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and mixtures of these two components using glass surfaces in a mini-traction machine. We compared our data with those obtained using flat silica surfaces in previous atomic force microscopy studies, and we also highlighted insights on hyaluronan–phospholipid interactions gained from recent simulations. Our data demonstrate that hyaluronan alone does not provide any lubricating benefit, but DPPC alone and in mixtures with hyaluronan reduces the friction force by an order of magnitude.
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12
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Moon HH, Choi EJ, Yun SH, Kim YC, Premkumar T, Song C. Aqueous lubrication and wear properties of nonionic bottle-brush polymers. RSC Adv 2022; 12:17740-17746. [PMID: 35765345 PMCID: PMC9199083 DOI: 10.1039/d2ra02711a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/09/2022] [Indexed: 11/21/2022] Open
Abstract
The usage of aqueous lubricants in eco-friendly bio-medical friction systems has attracted significant attention. Several bottle-brush polymers with generally ionic functional groups have been developed based on the structure of biological lubricant lubricin. However, hydrophilic nonionic brush polymers have attracted less attention, especially in terms of wear properties. We developed bottle-brush polymers (BP) using hydrophilic 2-hydroxyethyl methacrylate (HEMA), a highly biocompatible yet nonionic molecule. The lubrication properties of polymer films were analyzed in an aqueous state using a ball-on-disk, which revealed that BPHEMA showed a lower aqueous friction coefficient than linear poly(HEMA), even lower than hyaluronic acid (HA) and polyvinyl alcohol (PVA), which are widely used as lubricating polymers. Significantly, we discovered that the combination of HA, PVA, and BPHEMA is demonstrated to be essential in influencing the surface wear properties; the ratio of 1 : 2 (HA : BPHEMA) had the maximum wear resistance, despite a slight increase in the aqueous friction coefficient.
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Affiliation(s)
- Hwi Hyun Moon
- Department of Chemistry, Sungkyunkwan University Suwon Gyeonggi 16419 Republic of Korea
| | - Eun Jung Choi
- Department of Chemistry, Sungkyunkwan University Suwon Gyeonggi 16419 Republic of Korea
| | - Sang Ho Yun
- Department of Chemistry, Sungkyunkwan University Suwon Gyeonggi 16419 Republic of Korea
| | - Youn Chul Kim
- Department of Chemical Engineering, Sungkyunkwan University Suwon Gyeonggi 16419 Republic of Korea
| | - Thathan Premkumar
- Department of Chemistry, Sungkyunkwan University Suwon Gyeonggi 16419 Republic of Korea .,The University College, Sungkyunkwan University Suwon Gyeonggi 16419 Republic of Korea
| | - Changsik Song
- Department of Chemistry, Sungkyunkwan University Suwon Gyeonggi 16419 Republic of Korea
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13
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Shi J, Xu L, Qiu D. Effective Antifogging Coating from Hydrophilic/Hydrophobic Polymer Heteronetwork. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2200072. [PMID: 35285176 PMCID: PMC9109053 DOI: 10.1002/advs.202200072] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/21/2022] [Indexed: 05/20/2023]
Abstract
Fogging on optical devices may severely impair vision, resulting in unacceptable adverse consequences. Hydrophilic coatings can prevent surface fogging by instantly facilitating pseudo-film water condensation but suffer from short antifogging duration due to water film thickening with further condensation. Here, an innovative strategy is reported to achieve longer antifogging duration via thickening the robust bonded hydrophilic/hydrophobic polymer heteronetwork coating to enhance its water absorption capacity. The combination of strong interfacial adhesion and hydrophilic/hydrophobic heteronetwork structure is key to this approach, which avoids interfacial failure and swelling-induced wrinkles under typical fogging conditions. The developed antifogging coating exhibits prolonged antifogging durations over a wide temperature range for repetitious usages. Eyeglasses coated with this coating successfully maintained fog-free vision in two typical scenarios. Besides, the coating recipes developed in this study also have potential as underwater glues as they demonstrate strong adhesions to both glass and polymer substrates in wet conditions.
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Affiliation(s)
- Junhe Shi
- Beijing National Laboratory for Molecular SciencesCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing100190China
- University of Chinese Academy of SciencesBeijing100049China
| | - Liju Xu
- Beijing National Laboratory for Molecular SciencesCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing100190China
| | - Dong Qiu
- Beijing National Laboratory for Molecular SciencesCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing100190China
- University of Chinese Academy of SciencesBeijing100049China
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14
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Lin W, Goldberg R, Klein J. Poly-phosphocholination of liposomes leads to highly-extended retention time in mice joints. J Mater Chem B 2022; 10:2820-2827. [PMID: 35099493 PMCID: PMC9007059 DOI: 10.1039/d1tb02346b] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface-attached layers of phosphatidylcholine (PC) lipid vesicles (liposomes) may reduce the friction coefficient μ (= force-to-slide/load) between the sliding surfaces down to μ ≈ 10−3–10−4 up to tens of atm contact pressures, as high as those in the major joints (hips or knees). Such friction reduction is attributed to hydration lubrication by the highly-hydrated phosphocholine head-groups exposed at the outer vesicle surfaces. It has been suggested therefore that intra-articular (IA) administration of liposomes as potential boundary lubricants may alleviate degenerative, friction-associated joint conditions such as osteoarthritis (OA), which is associated with insufficient lubrication at the articular cartilage surface. To overcome the problem, common to all nanoparticles, of rapid removal by the mononuclear phagocyte system, as well as to ensure long-term colloidal stability during storage, functionalizing liposomes with poly(ethylene glycol) moieties, PEGylation, is often used. Here we describe a different liposome functionalization approach, using poly(2-methacryloyloxyethyl phosphorylcholine), PMPC, moieties (strictly, lipid–PMPC conjugates), and compare the retention time in mice joints of such PMPCylated liposomes with otherwise-identical but PEGylated vesicles following IA administration. We find, using fluorescence labeling and in vivo optical imaging, that when PMPC-stabilized liposomes are injected into mice knee joints, there is a massive increase of the vesicles’ retention half-life in the joints of about (4–5)-fold (ca. 300–400% increase in retention time) compared with the PEGylated liposomes (and some 100-fold longer than the retention time of intra-articularly injected hyaluronan or HA). Such PMPCylated liposomes are therefore promising candidates as potential long-lived boundary lubricants at the articular cartilage surface, with implication for friction-associated pathologies. Moreover, as lipid vesicles are well known to be efficient drug carriers, such long retention in the joints may enable analgesic or anti-inflammatory agents for joint pathologies to be more efficiently delivered via IA administration using PMPCylated liposomal vehicles relative to PEGylated ones. PMPCylated liposomes injected into mice joints show a massive increase in retention half-life compared with PEGylated liposomes (or hyaluronan, HA), making them promising candidates as boundary lubricants at articular cartilage, or as drug carriers.![]()
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Affiliation(s)
- Weifeng Lin
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Ronit Goldberg
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Jacob Klein
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel.
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15
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Boundary lubrication with aqueous solutions of silicone-based amphiphilic block copolymer aggregates: effect of concentration. Polym J 2021. [DOI: 10.1038/s41428-021-00515-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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17
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Burgess D, Li N, Rosik N, Fryer PJ, McRobbie I, Zhang H, Zhang ZJ. Surface-Grafted Poly(ionic liquid) that Lubricates in Both Non-polar and Polar Solvents. ACS Macro Lett 2021; 10:907-913. [PMID: 34306821 PMCID: PMC8296680 DOI: 10.1021/acsmacrolett.1c00174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/22/2021] [Indexed: 11/29/2022]
Abstract
![]()
We show that a surface-grafted
polymer brush, 1-n-butyl-3-vinyl imidazolium bromide-based
poly(ionic liquids), is
able to reduce the interfacial friction by up to 66% and 42% in dodecane
and water, respectively. AFM-based force spectroscopy reveals that
the polymer brush adopts distinctively different interfacial conformations:
swollen in water but collapsed in dodecane. Minimal surface adhesion
was observed with both polymer conformations, which can be attributed
to steric repulsion as the result of a swollen conformation in water
or surface solvation when the hydrophobic fraction of the polymer
was exposed to the dodecane. The work brings additional insight on
the polymer lubrication mechanism, which expands the possible design
of the polymer architecture for interfacial lubrication and modification.
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Affiliation(s)
- David Burgess
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Na Li
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, No. 122 Luoshi Road, Wuhan, 430070, People’s Republic of China
| | - Nicole Rosik
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Peter J. Fryer
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Ian McRobbie
- Innospec Inc., Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire, CH65 4EY, United Kingdom
| | - Haining Zhang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, No. 122 Luoshi Road, Wuhan, 430070, People’s Republic of China
| | - Zhenyu J. Zhang
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
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Cao H, Xu W, Guo X. The wormlike micelles formed using an ionic liquid surfactant and polar organic solvents at low temperature without additives and their lubricant properties. SOFT MATTER 2021; 17:1437-1444. [PMID: 33326550 DOI: 10.1039/d0sm01825b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Wormlike micelles (or reverse wormlike micelles) are flexible cylindrical chains that are normally formed in water (or a nonpolar organic solvent) at 25.0 °C or above; the formation of wormlike micelles at lower temperatures is rare. Here, we have reported wormlike micelles formed at low temperature using an ionic liquid surfactant (1-octadecyl-3-nonyl imidazolium bromide) in polar organic solvents (including 1,3-propanediol, 1,2-propylene glycol, N,N-dimethylformamide, and glycerol/1,2-propylene glycol mixture) in the absence of any additives. The viscoelasticity and morphology of the wormlike micelles were studied using rheology, small-angle X-ray scattering, and cryo-transmission electron microscopy. The viscoelastic properties of the wormlike micelles in polar solvents are affected by the solvent type (or the weight ratio of glycerol to 1,2-propylene glycol), surfactant concentration, and temperature. Moreover, the G' and G'' crossover twice in the dynamic curves, which is different from the case in water. The first crossover (at low frequency) corresponds to the relaxation time for the alkyl chains to disentangle from the transient network, and the second crossover (at high frequency) is related to the segmental motion of the chains. Furthermore, the tribological performance of these wormlike micelles is investigated at low temperature. It is found that the protective film (formed by the physical adhesion of the wormlike micelles on the surface of friction disk pair) and the tribochemical reaction together lead to good antifriction and antiwear performance, which indicates the application prospects of these wormlike micelles in low-temperature lubrication.
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Affiliation(s)
- Huijiao Cao
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, P. R. China.
| | - Wenlin Xu
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, P. R. China.
| | - Xia Guo
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, P. R. China.
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19
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Sułek MW, Bąk-Sowińska A, Przepiórka J. Ecological Cutting Fluids. MATERIALS 2020; 13:ma13245812. [PMID: 33352815 PMCID: PMC7765869 DOI: 10.3390/ma13245812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 11/18/2022]
Abstract
This study deals with metalworking fluids (MWFs). According to DIN 51385, depending on their base, the fluids are divided into oil and water fluids. The oil bases include, among others, mineral, synthetic, vegetable and paraffin oils. This division does not comprise surfactant solutions which can be successfully used in metalworking. Due to the fact that this type of fluid was not qualified, a new type of lubricant based on the aqueous solutions of surfactants has been proposed. Two new notions have been introduced: surfactant working fluids (SWFs) for working fluids and surfactant lubricants (SLs) for all kinds of lubricants as a broader term. The effect of the physicochemical properties of aqueous solutions of sodium lauroyl sarcosinate (SLS), also known as sodium N-dodecanoyl-N-methyl glycinate, on tribological properties determined using a four-ball machine (Tester T-02) (Łukasiewicz Research Network—The Institute for Sustainable Technologies, Radom, Poland) was analyzed. On the basis of aqueous SLS solutions a composition of working fluids was developed and their functional properties were verified by means of tribological and stand tests as well as during operation. The test results obtained clearly indicate that functional properties of 2% solutions of sodium lauroyl sarcosinate with a foam inhibitor (0.05%) and a biocide (0.1%) are comparable to those of a quality commercial hydraulic fluid.
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Affiliation(s)
| | | | - Jacek Przepiórka
- Faculty of Chemical Engineering and Commodity Science, Kazimierz Pulaski University of Technology and Humanities in Radom, 26-600 Radom, Poland;
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20
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Feng S, Liu Y, Li J, Wang H, Wen S. Insight into the Lubrication Behavior of Phospholipids Pre-adsorbed on Silica Surfaces at Different Adsorption Temperatures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13477-13484. [PMID: 33136405 DOI: 10.1021/acs.langmuir.0c02192] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phospholipids, as essential components in joint synovial fluid, play a dominant role in joint lubrication. In this study, atomic force microscopy was used to evaluate the normal and shear forces between two surfaces bearing three types of phospholipids with different acyl chain lengths, which were pre-adsorbed onto silica surfaces at different temperatures (25, 45, and 60 °C). When the pre-adsorption temperature was below the phospholipid phase transition temperature (Tm), a super-low friction coefficient [1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC): 0.002; 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC): 0.007] between two opposing silica surfaces in water was achieved because of the super-low shear strength of the hydration shell and robustness of the vesicle when the load was less than the critical value (DSPC: 500 nN; DPPC: 85 nN). However, when the pre-adsorption temperature exceeded Tm, the silica surface was covered by a bilayer structure with many defects, which exhibited poor adsorption density and low bearing capacity, resulting in a relatively high friction coefficient. This study gains insights into the influence of structure and temperature on the lubrication mechanism of phospholipids as biolubricants, providing guidance for the application of artificial joint synovial fluid.
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Affiliation(s)
- Shaofei Feng
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Jinjin Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Hongdong Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Shizhu Wen
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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21
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Bonyadi SZ, Demott CJ, Grunlan MA, Dunn AC. Cartilage-like tribological performance of charged double network hydrogels. J Mech Behav Biomed Mater 2020; 114:104202. [PMID: 33243694 DOI: 10.1016/j.jmbbm.2020.104202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/16/2020] [Accepted: 11/06/2020] [Indexed: 10/23/2022]
Abstract
A synthetic hydrogel material may offer utility as a cartilage replacement if it is able to maintain low friction in different sliding environments and achieve bulk mechanical properties to withstand the severe environment of the joint. In this work, we compared the tribological behavior of four double network (DN) hydrogels to that of fresh porcine cartilage in both water and fetal bovine serum (FBS). The DN hydrogels were comprised of a negatively charged 1st network and a 2nd network wherein comonomers of varying charge (i.e. neutral, positive, negative, and zwitterionic) were introduced at 10 wt% to an otherwise neutral network. A steel ball probe was used to perform microindentation tests to determine the surface elastic modulus of the samples and estimate their contact areas during sliding. Friction tests using a stationary probe with a stage that reciprocated at a range of speeds were performed to develop lubrication curves in both water and FBS. We found that the DN hydrogels with a neutral or zwitterionic 2nd network had the lowest friction and shear stresses, notably below that of cartilage. The differences in charge and structure of the samples were more evident in water than in FBS, as the lubrication responses for all the hydrogels spanned a wider range of values. In FBS, the lubrication responses were pushed towards elasto-hydrodynamics with nearly all friction coefficient values falling below 0.3. This indicates that the FBS interacts with the hydrogels and cartilage samples in a similar manner as that of cartilage by maintaining a robust layer of solution at the interface during sliding. These DN hydrogels prove to fulfill, and in some cases surpass, the lubrication demands for cartilage replacement in load bearing joints.
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Affiliation(s)
- Shabnam Z Bonyadi
- Department of Mechanical Science & Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Connor J Demott
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Melissa A Grunlan
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA; Department of Materials Science & Engineering, Texas A&M University, College Station, TX, USA; Department of Chemistry, Texas A&M University, College Station, TX, USA
| | - Alison C Dunn
- Department of Mechanical Science & Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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22
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Dong R, Bao L, Yu Q, Wu Y, Ma Z, Zhang J, Cai M, Zhou F, Liu W. Effect of Electric Potential and Chain Length on Tribological Performances of Ionic Liquids as Additives for Aqueous Systems and Molecular Dynamics Simulations. ACS APPLIED MATERIALS & INTERFACES 2020; 12:39910-39919. [PMID: 32804469 DOI: 10.1021/acsami.0c11016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
As pure lubricants, ILs performed very well by forming the classical self-assembly bilayer at the sliding interface. The interface mechanism is still not clear in a very polar, e.g., water-based lubricating system. In this work, the interfacial absorption and tribological behavior of carboxylic alkanolamine ionic liquids (CAILs) serving as aqueous lubricating additives were studied by applying positive and negative potentials on the friction pair, accompanied by the comprehensive discussion of data from critical micelle concentration, quartz crystal microbalance, ECR, and MD results. The results reveal that the adsorption behavior, unexpectedly, was affected by the high polarity of H2O, where a less dense double-layer structure is observed at the interface by model imitation. Conversely, the monomolecular adsorption layer constructed electrostatically between the polar head (-COO-) and the positive base dominates the tribofilm. Meanwhile, the cations are partially accumulating around anions in the presence of static electricity, which does not form a neat and dense one-to-one corresponding cation-anion pair. In the solution, the IL maintains a state of dissociation and minor agglomeration. Furthermore, an increase in alkyl chains contributes to the thickness of the protective film generated by CAILs on the sliding asperity. Eventually, the synergistic effect from physical adsorption and the tribochemical reaction is responsible for excellent lubricity and antiwear performance of CAILs.
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Affiliation(s)
- Rui Dong
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Luyao Bao
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Qiangliang Yu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yang Wu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Zhengfeng Ma
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Jiaying Zhang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meirong Cai
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Feng Zhou
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Weimin Liu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
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23
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Zander T, Garamus VM, Dédinaité A, Claesson PM, Bełdowski P, Górny K, Dendzik Z, Wieland DCF, Willumeit-Römer R. Influence of the Molecular Weight and the Presence of Calcium Ions on the Molecular Interaction of Hyaluronan and DPPC. Molecules 2020; 25:E3907. [PMID: 32867196 PMCID: PMC7504306 DOI: 10.3390/molecules25173907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/18/2020] [Accepted: 08/25/2020] [Indexed: 12/03/2022] Open
Abstract
Hyaluronan is an essential physiological bio macromolecule with different functions. One prominent area is the synovial fluid which exhibits remarkable lubrication properties. However, the synovial fluid is a multi-component system where different macromolecules interact in a synergetic fashion. Within this study we focus on the interaction of hyaluronan and phospholipids, which are thought to play a key role for lubrication. We investigate how the interactions and the association structures formed by hyaluronan (HA) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) are influenced by the molecular weight of the bio polymer and the ionic composition of the solution. We combine techniques allowing us to investigate the phase behavior of lipids (differential scanning calorimetry, zeta potential and electrophoretic mobility) with structural investigation (dynamic light scattering, small angle scattering) and theoretical simulations (molecular dynamics). The interaction of hyaluronan and phospholipids depends on the molecular weight, where hyaluronan with lower molecular weight has the strongest interaction. Furthermore, the interaction is increased by the presence of calcium ions. Our simulations show that calcium ions are located close to the carboxylate groups of HA and, by this, reduce the number of formed hydrogen bonds between HA and DPPC. The observed change in the DPPC phase behavior can be attributed to a local charge inversion by calcium ions binding to the carboxylate groups as the binding distribution of hyaluronan and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine is not changed.
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Affiliation(s)
- Thomas Zander
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht: Centre for Materials and Costal Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany; (T.Z.); (V.M.G.); (R.W.-R.)
| | - Vasil M. Garamus
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht: Centre for Materials and Costal Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany; (T.Z.); (V.M.G.); (R.W.-R.)
| | - Andra Dédinaité
- Department of Chemistry, Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-10044 Stockholm, Sweden; (A.D.); (P.M.C.)
- Division of Bioscience and Materials, RISE Research Institutes of Sweden, SE-114 86 Stockholm, Sweden
| | - Per M. Claesson
- Department of Chemistry, Surface and Corrosion Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-10044 Stockholm, Sweden; (A.D.); (P.M.C.)
- Division of Bioscience and Materials, RISE Research Institutes of Sweden, SE-114 86 Stockholm, Sweden
| | - Piotr Bełdowski
- Institue of Mathematics and Physics, UTP University of Science and Technology, al. Kaliskiego 7, 85-796 Bydgoszcz, Poland;
| | - Krzysztof Górny
- Faculty of Science and Technology, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland; (K.G.); (Z.D.)
| | - Zbigniew Dendzik
- Faculty of Science and Technology, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland; (K.G.); (Z.D.)
| | - D. C. Florian Wieland
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht: Centre for Materials and Costal Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany; (T.Z.); (V.M.G.); (R.W.-R.)
| | - Regine Willumeit-Römer
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht: Centre for Materials and Costal Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany; (T.Z.); (V.M.G.); (R.W.-R.)
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24
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Cisternas E, dos Santos GJ, Flores M, Vogel EE, Ramirez-Pastor AJ. Self-assembled monolayer formation of pentamers-like molecules onto FCC(111) surfaces: the case of curcuminoids onto Au(111) surface. NANO EXPRESS 2020. [DOI: 10.1088/2632-959x/ab8961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
The adsorption of rigid straight electrically polarized pentamers over a FCC(111) surface is studied. The model was inspired by the deposition of 2-thiophene molecules over the Au(111) surface, which was previously characterized by experimental techniques and simulated under the frame of the density functional theory. We now obtain and report the charge distribution of the molecule which allows to propose a deposition model followed by Monte Carlo simulations over an ad-hoc lattice gas model. We show that for a certain value of the chemical potential there exists an isotropic-nematic phase transition which can explain the formation of a self-assembled monolayer like the one observed in the transmission electron microscopy images. An order parameter is defined to characterize the transition which presents a step-like behavior at a critical chemical potential value. The possible nature of the nematic transition in conjunction with an ergodicity breakdown is discussed as future work by means of statistical physics techniques.
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Miyamoto T, Yamazaki N, Watanabe S, Yamada S. Aqueous Lubrication with the Molecularly Confined Films of Silicone-Based Amphiphilic Block Copolymer Aggregates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15784-15794. [PMID: 31656076 DOI: 10.1021/acs.langmuir.9b03212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The confined film structures and tribological properties of the dilute aqueous solution of a silicone-based amphiphilic block copolymer, bis-isobutyl poly(ethylene glycol) (PEG)-14/amodimethicone (BIPA) copolymer, between mica surfaces were investigated. The BIPA copolymer existed as positively charged water-soluble aggregates in the solution. The adsorption behavior of the BIPA copolymer aggregates on a mica surface from solution was studied using an atomic force microscope (AFM); the result showed the immediate formation of a uniform adsorbed BIPA copolymer layer, followed by the gradual deposition of BIPA aggregates on the top of the adsorbed layer. Friction measurements were carried out using the surface forces apparatus (SFA) for the confined films of BIPA copolymer solution between mica surfaces, which revealed two different sliding film structures depending on the elapsed time after surface preparation. The sliding film consisting of two adsorbed BIPA copolymer layers was obtained for a relatively short elapsed time (not longer than 3 h), which had an extremely low friction coefficient μ (of the order of 10-5). The sliding film on the following day (elapsed time of approximately 24 h) had the structure of a deposited/kinetically trapped BIPA aggregate layer confined between the opposing adsorbed layers, and the μ values were within the range from 10-4 to 10-3. Our results suggest that the different elapsed time ranges and resulting absence or presence of the intervening layer of trapped aggregates between the absorbed layers determine the tribological properties of the confined films. Molecular friction mechanisms are discussed for the two sliding structures, which give insight into using amphiphilic block copolymer aggregates for a new class of aqueous lubrication system to design extremely low friction interfaces.
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Affiliation(s)
- Takumi Miyamoto
- R&D - Analytical Science Research , Kao Corporation , 1334 Minato , Wakayama , Wakayama 640-8580 , Japan
| | - Naoyuki Yamazaki
- R&D - Hair Care Products Research , Kao Corporation , 2-1-3 Bunka , Sumida-ku , Tokyo 131-8501 , Japan
| | - Shunichi Watanabe
- R&D - Hair Care Products Research , Kao Corporation , 2-1-3 Bunka , Sumida-ku , Tokyo 131-8501 , Japan
| | - Shinji Yamada
- R&D - Analytical Science Research , Kao Corporation , 1334 Minato , Wakayama , Wakayama 640-8580 , Japan
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26
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Lin W, Klein J. Control of surface forces through hydrated boundary layers. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.10.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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27
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Zander T, Wieland DCF, Raj A, Salmen P, Dogan S, Dėdinaitė A, Garamus VM, Schreyer A, Claesson PM, Willumeit-Römer R. Influence of high hydrostatic pressure on solid supported DPPC bilayers with hyaluronan in the presence of Ca 2+ ions. SOFT MATTER 2019; 15:7295-7304. [PMID: 31483431 DOI: 10.1039/c9sm01066a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The molecular mechanisms responsible for outstanding lubrication of natural systems, like articular joints, have been the focus of scientific research for several decades. One essential aspect is the lubrication under pressure, where it is important to understand how the lubricating entities adapt under dynamic working conditions in order to fulfill their function. We made a structural investigation of a model system consisting of two of the molecules present at the cartilage interface, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and hyaluronan, at high hydrostatic pressure. Phospholipid layers are found at the cartilage surfaces and are able to considerably reduce friction. Their behavior under load and varied solution conditions is important as pressures of 180 bar are encountered during daily life activities. We focus on how divalent ions, like Ca2+, affect the interaction between DPPC and hyaluronan, as other investigations have indicated that calcium ions influence their interaction. It could be shown that already low amounts of Ca2+ strongly influence the interaction of hyaluronan with DPPC. Our results suggest that the calcium ions increase the amount of adsorbed hyaluronan indicating an increased electrostatic interaction. Most importantly, we observe a modification of the DPPC phase diagram as hyaluronan absorbs to the bilayer which results in an Lα-like structure at low temperatures and a decoupling of the leaflets forming an asymmetric bilayer structure.
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Affiliation(s)
- Thomas Zander
- Helmholtz-Zentrum Geesthacht, Centre for Materials and Costal Research, Institute of Materials Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany.
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28
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Kékicheff P. The long-range attraction between hydrophobic macroscopic surfaces. Adv Colloid Interface Sci 2019; 270:191-215. [PMID: 31277036 DOI: 10.1016/j.cis.2019.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 10/26/2022]
Abstract
Direct measurements of the long-range strongly attractive force observed between macroscopic hydrophobic surfaces across aqueous solutions are reexamined in light of recent experiments and theoretical developments. The focus is on systems in the absence of submicroscopic bubbles (preexistent or induced) to avoid capillary bridging forces. Other possible interferences to the measurements are also eliminated. The force-distance profiles are obtained directly (no contributions from electrical double layer or hydrodynamics) between symmetric identical hydrophobic surfaces, overall charge-neutral, at the thermodynamic equilibrium and in a quenched state. Therefore in the well-defined geometry of crossed-cylinders, sphere-flat, or sphere-sphere, there is no additional interaction to be considered except the ever-present dispersion forces, negligible at large separations. For the three main categories of substrates rendered hydrophobic, namely surfaces obtained with surfactant monolayers physically adsorbed from solution to deposited ones, and substrates coated with a hydrophobizing agent bonded chemically onto the surface, the interaction energy scales as A exp (-2κD)/2κD at large separations, with measured decay lengths in accord with theoretical predictions, simply being half the Debye screening length, κ-1/2, at least in non vanishing electrolyte. Taken together with the prefactor A scaling as the ionic strength, the interaction energy is demonstrated to have an electrostatic origin in all the systems. Thanks to our recent SFAX coupling force measurements with x-ray solution scattering under controlled nano-confinement, the microstructuration of the adsorbed film emerges as an essential feature in the molecular mechanism for explaining the observed attraction of larger magnitude than dispersion forces. The adsorption of pairs of positive and negative ions on small islands along the interface, the fluctuation of the surface charge density around a zero mean-value with desorption into or adsorption from the electrolyte solution, the correlations in the local surface ion concentrations along the surfaces, the redistribution of counterions upon intersurface variation, all contribute and are tuned finely by the inhomogeneities and defects present in the hydrophobic layers. It appears that the magnitude of the interacting energy can be described by a single master curve encompassing all the systems.
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Łysik D, Niemirowicz-Laskowska K, Bucki R, Tokajuk G, Mystkowska J. Artificial Saliva: Challenges and Future Perspectives for the Treatment of Xerostomia. Int J Mol Sci 2019; 20:ijms20133199. [PMID: 31261876 PMCID: PMC6651665 DOI: 10.3390/ijms20133199] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/21/2019] [Accepted: 06/28/2019] [Indexed: 12/16/2022] Open
Abstract
The chronic sensation of a dry mouth is a disease condition called xerostomia and affects a large part of the population. Xerostomia is associated with decreased secretion, or more often, qualitative changes in saliva proteins and immunoglobulin concentrations that develop as a result of salivary gland dysfunction. Several reasons causing dry mouth were described, and usually, they include taking medications, diseases or radiotherapy. In some situations, when it is difficult to use salivary stimulants or salivary gland damage is irreversible, the only option might seem to be saliva substitutes. The paper presents the most important aspects considering saliva preparations. The rheological and lubricating properties and the reconstruction of the complex saliva structure has been the main purpose of research. The biological properties of saliva preparations were also widely discussed. As part of the work, the antimicrobial effect of three commercial saliva preparations was tested. Finally, inadequate antimicrobial properties against the strains isolated from the oral cavity were demonstrated. The development of salivary substitutes, in particular, the improvement of antimicrobial properties, can be achieved using nanotechnology, including drug delivery systems containing nanocarriers.
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Affiliation(s)
- Dawid Łysik
- Department of Materials Engineering and Production, Bialystok University of Technology, Wiejska 45C, 15-351 Bialystok, Poland
| | | | - Robert Bucki
- Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2C, 15-222 Bialystok, Poland
| | - Grażyna Tokajuk
- Department of Integrated Dentistry, Medical University of Bialystok, M. Sklodowskiej-Curie 24a, 15-276 Bialystok, Poland
| | - Joanna Mystkowska
- Department of Materials Engineering and Production, Bialystok University of Technology, Wiejska 45C, 15-351 Bialystok, Poland.
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Kékicheff P, Contal C. Cationic-Surfactant-Coated Mica Surfaces below the Critical Micellar Concentration: 1. Patchy Structures As Revealed by Peak Force Tapping AFM Mode. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3087-3107. [PMID: 30691263 DOI: 10.1021/acs.langmuir.8b03781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The morphology and structure of the self-assembled surfactant aggregates at the solid-liquid interface remain controversial. For the well-studied system of cationic cetyltrimethylammonium bromide (C16TAB) adsorbed onto the opposite negatively charged, atomically smooth mica surface, a variety of surface aggregates have been previously reported: AFM imaging pointing to cylinders and surface micelles as opposed to mono/bilayer-like structures revealed by neutron and X-ray reflectometry, NMR, spectroscopic techniques, and numerical simulations. To reconcile with the latter results, we revisit the morphometry of the C16TAB-coated mica surfaces using the recent peak force tapping (PFT-AFM) mode that allows fragile structures to be imaged with the lowest possible applied force. The evolution of the structural organization at the mica-water interface is investigated above the Krafft boundary over a wide concentration range (from 1/1000 to 2 cmc) after long equilibration times to ensure thermodynamic equilibrium. A complex but fairly complete picture has emerged: At very low concentrations, the C16TAB surfactants adsorb as isolated molecules before forming small clusters. Above 1/140 cmc, monolayer-like stripes are formed. As the concentration is increased, a connected network of these patches progressively covers the mica substrate. Above 1/80 cmc, bilayer-like patches build on top of the underlying monolayer, and ultimately a complete bilayer (at about half the cmc) covers the entire mica substrate. Thanks to the less invasive PFT-AFM imaging mode, our observations not only agree with the theoretical predictions and numerical simulations but also reconcile, at last, the direct observations by means of the AFM imaging technique with the results obtained with other techniques.
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Affiliation(s)
- Patrick Kékicheff
- Université de Strasbourg, CNRS Institut Charles Sadron , 23 rue du Loess , 67034 Strasbourg Cedex 2, France
| | - Christophe Contal
- Université de Strasbourg, CNRS Institut Charles Sadron , 23 rue du Loess , 67034 Strasbourg Cedex 2, France
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31
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Sarkar A, Andablo-Reyes E, Bryant M, Dowson D, Neville A. Lubrication of soft oral surfaces. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.01.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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32
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Leivers M, Seddon JM, Declercq M, Robles E, Luckham P. Measurement of Forces between Supported Cationic Bilayers by Colloid Probe Atomic Force Microscopy: Electrolyte Concentration and Composition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:729-738. [PMID: 30562468 DOI: 10.1021/acs.langmuir.8b03555] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The interactions between supported cationic surfactant bilayers were measured by colloidal probe atomic force spectroscopy, and the effect of different halide salts was investigated. Di(alkylisopropylester)dimethylammonium methylsulfate (DIPEDMAMS) bilayers were fabricated by the vesicle fusion technique on muscovite mica. The interactions between the bilayers were measured in increasing concentrations of NaCl, NaBr, NaI, and CaCl2. In NaCl, the bilayer interactions were repulsive at all concentrations investigated, and the Debye length and surface potential were observed to decrease with increasing concentration. The interactions were found to follow the electrical double layer (EDL) component of DLVO theory well. However, van der Waals forces were not detected; instead, a strong hydration repulsion was observed at short separations. CaCl2 had a similar effect on the interactions as NaCl. NaBr and NaI were observed to be more efficient at decreasing surface potential than the chloride salts, with the efficacy increasing with the ionic radius.
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Affiliation(s)
- Matthew Leivers
- Department of Chemistry , Imperial College London , London SW7 2AZ , United Kingdom
- Department of Chemical Engineering , Imperial College London , London SW7 2AZ , United Kingdom
| | - John M Seddon
- Department of Chemistry , Imperial College London , London SW7 2AZ , United Kingdom
| | - Marc Declercq
- The Procter & Gamble Company, Brussels Innovation Center , 1853 Strombeek Bever Temselaan 100 , 1853 Grimbergen , Belgium
| | - Eric Robles
- The Procter & Gamble Company, Newcastle Innovation Center , Whitley Road , Longbenton, Newcastle-Upon-Tyne NE12 9TS , United Kingdom
| | - Paul Luckham
- Department of Chemical Engineering , Imperial College London , London SW7 2AZ , United Kingdom
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Bełdowski P, Weber P, Dėdinaitė A, Claesson PM, Gadomski A. Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment. SOFT MATTER 2018; 14:8997-9004. [PMID: 30394485 DOI: 10.1039/c8sm01388h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and the small world network approach to investigate dynamic couplings using a distance map applied to oxygen atoms in a chain of hyaluronic acid in the presence of phospholipids and water. The distance characterizing the coupling can be defined in various ways to bring out the most evident differences between various scenarios of the polymer chain conformation We show herein a physical distance understood as H-bond length and classes of these distances which are defined in a coarse-grained picture of the molecule. Simulation results indicate that addition of phospholipids has little influence on hyaluronic acid crosslinking. However, longer chains and addition of lipids promote appreciably long lasting (resilient) networks that may be of importance in biological systems. Specific sites for hydrogen bonding of phospholipids to hyaluronic acid have also been identified.
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Affiliation(s)
- Piotr Bełdowski
- Institute of Mathematics and Physics, UTP University of Science and Technology, al. Kaliskiego 7, 85-796 Bydgoszcz, Poland.
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34
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Yao H, Kang J, Li W, Liu J, Xie R, Wang Y, Liu S, Wang DA, Ren L. Novel
β
-TCP/PVA bilayered hydrogels with considerable physical and bio-functional properties for osteochondral repair. Biomed Mater 2017; 13:015012. [DOI: 10.1088/1748-605x/aa8541] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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35
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Ho TT, Selway N, Krasowska M, Yakubov GE, Stokes JR, Beattie DA. Formation and tribology of fucoidan/chitosan polyelectrolyte multilayers on PDMS substrates. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.biotri.2017.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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36
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Bartenstein JE, Liu X, Lange K, Claesson PM, Briscoe WH. Polymersomes at the solid-liquid interface: Dynamic morphological transformation and lubrication. J Colloid Interface Sci 2017; 512:260-271. [PMID: 29073467 DOI: 10.1016/j.jcis.2017.10.065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/13/2017] [Accepted: 10/16/2017] [Indexed: 10/18/2022]
Abstract
Polymersomes are hollow spheres self-assembled from amphiphilic block copolymers of certain molecular architecture. Whilst they have been widely studied for biomedical applications, relatively few studies have reported their interfacial properties. In particular, lubrication by polymersomes has not been previously reported. Here, interfacial properties of polymersomes self-assembled from poly(butadiene)-poly(ethylene oxide) (PBD-PEO; molecular weight 10,400 g mol-1) have been studied at both hydrophilic and hydrophobic surfaces. Their morphology at silica and mica surfaces was imaged with quantitative nanomechanical property mapping atomic force microscopy (QNM AFM), and friction and surface forces they mediate under confinement between two surfaces were studied using colloidal probe AFM (CP-AFM). We find that the polymersomes remained intact but adopted flattened conformation once adsorbed to mica, with a relatively low coverage. However, on silica these polymersomes were unstable, rupturing to form donut shaped residues or patchy bilayers. On a silica surface hydrophobized with a 19 nm polystyrene (PS) film, the polymer vesicles formed a more stable layer with a higher surface coverage as compared to the hydrophilic surface, and the interfacial structure also evolved over time. Moreover, friction was greatly reduced on hydrophobized silica surfaces in the presence of polymersomes, suggesting their potential as effective aqueous lubricants.
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Affiliation(s)
- Julia E Bartenstein
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Xiaoyan Liu
- Surface and Corrosion Science, Drottning Kristinas Väg 51, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Kathrin Lange
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Per M Claesson
- Surface and Corrosion Science, Drottning Kristinas Väg 51, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Wuge H Briscoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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Schlaich A, Kappler J, Netz RR. Hydration Friction in Nanoconfinement: From Bulk via Interfacial to Dry Friction. NANO LETTERS 2017; 17:5969-5976. [PMID: 28910108 DOI: 10.1021/acs.nanolett.7b02000] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The viscous properties of nanoscopically confined water are important when hydrated surfaces in close contact are sheared against each other. Numerous experiments have probed the friction between atomically flat hydrated surfaces in the subnanometer separation regime and suggested an increased water viscosity, but the value of the effective viscosity of ultraconfined water, the mechanism of hydration layer friction, and the crossover to the dry friction limit are unclear. We study the shear friction between polar surfaces by extensive nonequilibrium molecular dynamics simulations in the linear-response regime at low shearing velocity, which is the relevant regime for typical biological applications. With decreasing water film thickness we find three consecutive friction regimes: For thick films friction is governed by bulk water viscosity. At separations of about a nanometer the highly viscous interfacial water layers dominate and increase the surface friction, while at the transition to the dry friction limit interfacial slip sets in. Based on our simulation results, we construct a confinement-dependent friction model which accounts for the additive friction contributions from bulklike water, interfacial water layers, and interfacial slip and which is valid for arbitrary water film thickness.
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Affiliation(s)
- Alexander Schlaich
- Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany
| | - Julian Kappler
- Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany
| | - Roland R Netz
- Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany
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38
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Abstract
In living organisms the aqueous medium is used for providing low friction forces. This is achieved by synergistic actions of different biomolecules that together accomplish a high load bearing capacity and sustain an easily sheared water layer.
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Affiliation(s)
- Andra Dėdinaitė
- KTH Royal Institute of Technology
- School of Chemical Science and Engineering
- Department of Chemistry
- Division of Surface and Corrosion Science
- Drottning Kristinas väg 51
| | - Per M. Claesson
- KTH Royal Institute of Technology
- School of Chemical Science and Engineering
- Department of Chemistry
- Division of Surface and Corrosion Science
- Drottning Kristinas väg 51
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