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Yamazaki R, Karyu N, Noda M, Fujii S, Nakamura Y. Quantitative measurement of physisorbed silane on a silica particle surface treated with silane coupling agents by thermogravimetric analysis. J Appl Polym Sci 2015. [DOI: 10.1002/app.43256] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ryota Yamazaki
- Department of Applied Chemistry; Osaka Institute of Technology; 5-16-1 Ohmiya Asahi-Ku, Osaka 535-8585 Japan
| | - Nozomi Karyu
- Department of Applied Chemistry; Osaka Institute of Technology; 5-16-1 Ohmiya Asahi-Ku, Osaka 535-8585 Japan
| | - Masayo Noda
- Department of Applied Chemistry; Osaka Institute of Technology; 5-16-1 Ohmiya Asahi-Ku, Osaka 535-8585 Japan
| | - Syuji Fujii
- Department of Applied Chemistry; Osaka Institute of Technology; 5-16-1 Ohmiya Asahi-Ku, Osaka 535-8585 Japan
| | - Yoshinobu Nakamura
- Department of Applied Chemistry; Osaka Institute of Technology; 5-16-1 Ohmiya Asahi-Ku, Osaka 535-8585 Japan
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Fukuda T, Fujii S, Nakamura Y, Sasaki M. Mechanical properties of silica particle-filled styrene-butadiene rubber composites containing polysulfide-type silane coupling agents: Influence of loading method of silane. J Appl Polym Sci 2013. [DOI: 10.1002/app.39175] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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An Q, Rider AN, Thostenson ET. Hierarchical composite structures prepared by electrophoretic deposition of carbon nanotubes onto glass fibers. ACS APPLIED MATERIALS & INTERFACES 2013; 5:2022-2032. [PMID: 23379418 DOI: 10.1021/am3028734] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Carbon nanotube/glass fiber hierarchical composite structures have been produced using an electrophoretic deposition (EPD) approach for integrating the carbon nanotubes (CNTs) into unidirectional E-glass fabric, followed by infusion of an epoxy polymer matrix. The resulting composites show a hierarchical structure, where the structural glass fibers, which have diameters in micrometer range, are coated with CNTs having diameters around 10-20 nm. The stable aqueous dispersions of CNTs were produced using a novel ozonolysis and ultrasonication technique that results in dispersion and functionalization in a single step. Ozone-oxidized CNTs were then chemically reacted with a polyethyleneimine (PEI) dendrimer to enable cathodic EPD and promote adhesion between the CNTs and the glass-fiber substrate. Deposition onto the fabric was accomplished by placing the fabric in front of the cathode and applying a direct current (DC) field. Microscopic characterization shows the integration of CNTs throughout the thickness of the glass fabric, where individual fibers are coated with CNTs and a thin film of CNTs also forms on the fabric surfaces. Within the composite, networks of CNTs span between adjacent fibers, and the resulting composites exhibit good electrical conductivity and considerable increases in the interlaminar shear strength, relative to fiber composites without integrated CNTs. Mechanical, chemical and morphological characterization of the coated fiber surfaces reveal interface/interphase modification resulting from the coating is responsible for the improved mechanical and electrical properties. The CNT-coated glass-fiber laminates also exhibited clear changes in electrical resistance as a function of applied shear strain and enables self-sensing of the transition between elastic and plastic load regions.
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Affiliation(s)
- Qi An
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, USA
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Diebold RM, Clarke DR. Smooth, aggregate-free self-assembled monolayer deposition of silane coupling agents on silicon dioxide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15513-15520. [PMID: 23066941 DOI: 10.1021/la303377w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Silane coupling agents (SCAs) are notorious for aggregating during deposition on oxide substrates, leading to nonuniform surface morphologies. To ameliorate this problem, we describe a vapor-phase deposition technique for silane coupling agents employing a spin-coated perfluoropolyether (PFPE) diffusion barrier that facilitates the formation of smooth, aggregate-free self-assembled monolayers (SAMs). Samples fabricated using PFPE barrier layers yielded SAMs exhibiting similar water contact angles, reduced water contact angle hysteresis, and a 2-fold reduction in rms roughness relative to those without a barrier. X-ray photoelectron spectroscopy confirms that the barrier layer can be completely removed after deposition, leaving behind a smooth monolayer. A basic analysis of the agglomerate separation ability of the barrier layers is discussed to understand the critical parameters involved. Generalized guidelines for selecting barrier materials are presented.
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Affiliation(s)
- Roger M Diebold
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
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Knorr DB, Jaye C, Fischer DA, Shoch AB, Lenhart JL. Manipulation of interfacial amine density in epoxy-amine systems as studied by near-edge X-ray absorption fine structure (NEXAFS). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15294-15304. [PMID: 23013540 DOI: 10.1021/la3033786] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this work, we investigate the ability to tune the quantity of surface amine functional groups in the interfacial region of epoxy-diamine composites using NEXAFS, a technique that is extremely sensitive to surface composition. Thereby, we employ a model surface (silicon wafer with the native oxide present) and, after deposition of an epoxy functionalized silane, we immersed the wafers in various diamines, followed by reaction with a diepoxy acting as a molecular probe. These results show that the number of available surface amines depends on the diamine chosen, wherein smaller molecular weight diamines provide more reaction sites. Subsequent experiments with mixtures of diamines undergoing competitive adsorption show that the amine quantity can be tailored by choice of the diamine mixture. Further experiments of diamine treated 3-(glycidoxypropyl) trimethoxysilane layers in a reacting epoxy/diamine showed that the surface reaction site density differences observed for adsorption experiments persisted in the reacting epoxy, implying that the surface reaction rate (and by extension, the surface amine concentration) dictate interfacial cross-link density up to the point of gelation.
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Affiliation(s)
- Daniel B Knorr
- U.S. Army Research Laboratory , Aberdeen Proving Ground, Maryland, United States
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Nakamura Y, Nishida Y, Fukuda T, Fujii S, Sasaki M. Mechanical properties of silane-treated silica particle-filled polyisoprene composites: Influence of the alkoxy group mixing ratio in silane coupling agent containing mercapto group. J Appl Polym Sci 2012. [DOI: 10.1002/app.38442] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Longley JE, Chaudhury MK. Determination of the Modulus of Thin Sol−Gel films Using Buckling Instability. Macromolecules 2010. [DOI: 10.1021/ma100642z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jonathan E. Longley
- Department of Chemical Engineering, Lehigh University, Bethlehem, Pennsylvania 18015
| | - Manoj K. Chaudhury
- Department of Chemical Engineering, Lehigh University, Bethlehem, Pennsylvania 18015
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Ismail AE, Grest GS, Heine DR, Stevens MJ, Tsige M. Interfacial Structure and Dynamics of Siloxane Systems: PDMS−Vapor and PDMS−Water. Macromolecules 2009. [DOI: 10.1021/ma802805y] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Gary S. Grest
- Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - David R. Heine
- Sandia National Laboratories, Albuquerque, New Mexico 87185
| | | | - Mesfin Tsige
- Department of Physics, Southern Illinois University, Mail Code 4401, Carbondale, Illinois 62901
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Jerman I, Vuk AS, Kozelj M, Orel B, Kovac J. A structural and corrosion study of triethoxysilyl functionalized POSS coatings on AA 2024 alloy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:5029-5037. [PMID: 18351793 DOI: 10.1021/la7037262] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A novel bifunctional polyhedral oligomeric silsesquioxane (POSS) based silane precursor R(x)R'(y)(SiO(3/2))(8), (x + y = 8), bearing 3-(N-(3-triethoxysilylpropyl)ureido)propyl (ureasil - U) and isooctyl (IO) groups (i.e., U(2)IO(6) POSS) was synthesized, and the corresponding coatings, prepared under the acid hydrolysis conditions, were studied in order to assess their corrosion inhibition of the AA 2024-T3 alloy. The U(2)IO(6) POSS precursor was made in two steps: in the first, an appropriate stoichiometric (2:6) mixture of 3-aminopropyltriethoxysilane (AP(2)) and isooctyltrimethoxysilane (IO(6)) was autoclaved under basic hydrolysis conditions giving AP(2)IO(6)(SiO(3/2))(8) cubes, which were reacted in the second step with 3-isocyanatopropyltriethoxysilane (ICPTES), leading to the bis end-capped sol-gel precursor U(2)IO(6) POSS having a cube-like structure. Coatings were made from sols catalyzed with acidified water. IR and (29)Si NMR spectroscopic studies combined with mass spectrometric measurements were employed to confirm the cube-like structure of AP(2)IO(6) and U(2)IO(6) POSS. The structure and morphology of the U(2)IO(6) POSS coatings were studied with the help of infrared reflection-absorption (IR RA) spectroscopic measurements combined with XPS and AFM measurements, providing information about the formation of partially self-assembled coatings. The degree of corrosion inhibition was assessed from the potentiodynamic measurements showing around 10 times smaller current densities for the coatings only 30-40 nm thick. Ex situ IR RA spectroelectrochemical measurements were performed by consecutive measurements of the IR RA spectra of U(2)IO(6) POSS coatings which were chronocoulometrically charged at different potentials. At potentials more positive than the corrosion potential (E(corr) approximately -0.5 V), the amide I bands shifted, indicating the formation of new urea-urea aggregations and associations, with the newly formed strong band at 1680-1690 cm(-1) suggesting the formation of amidonium ions. These results showed that the urea groups represented the weakest part of the coatings due to their tendency to protonation.
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Affiliation(s)
- Ivan Jerman
- National Institute of Chemistry, Hajdrihova 19, and JoZef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
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Dohi H, Horiuchi S. Locating a silane coupling agent in silica-filled rubber composites by EFTEM. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:12344-12349. [PMID: 17941652 DOI: 10.1021/la701537k] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A silane coupling agent (SA) was added to silica/rubber composites at different mixing temperatures and the formation of a coupling layer at the silica/rubber interface was investigated by energy-filtering transmission electron microscopy. Bis(triethoxysilypropyl)tetrasulfane (TESPT), which was used as the SA, reacted with the silanol groups on the silica surface and with styrene-butadiene rubber to form an interfacial coupling layer. The silicon and sulfur elemental distributions were analyzed by electron energy loss spectroscopy (EELS) and elemental mapping. The amount of TESPT trapped in the rubber matrix could be qualitatively estimated by EELS, and the in situ formed coupling layer could be characterized by elemental mapping. The result indicated that the formation of the coupling layer was affected by the mixing temperature. The technique described here will contribute to the study of interface-property relationships and the evaluation of the role of SAs in polymeric composites.
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Affiliation(s)
- Hidehiko Dohi
- SRI Research & Development Ltd., 2-1-1, Tsutsui-cho, Chuo-ku, Kobe 651-0071, Japan
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Reed J, Mishra B, Pittenger B, Magonov S, Troke J, Teitell MA, Gimzewski JK. Single molecule transcription profiling with AFM. NANOTECHNOLOGY 2007; 18:44032. [PMID: 20721301 PMCID: PMC2922717 DOI: 10.1088/0957-4484/18/4/044032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Established techniques for global gene expression profiling, such as microarrays, face fundamental sensitivity constraints. Due to greatly increasing interest in examining minute samples from micro-dissected tissues, including single cells, unorthodox approaches, including molecular nanotechnologies, are being explored in this application. Here, we examine the use of single molecule, ordered restriction mapping, combined with AFM, to measure gene transcription levels from very low abundance samples. We frame the problem mathematically, using coding theory, and present an analysis of the critical error sources that may serve as a guide to designing future studies. We follow with experiments detailing the construction of high density, single molecule, ordered restriction maps from plasmids and from cDNA molecules, using two different enzymes, a result not previously reported. We discuss these results in the context of our calculations.
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Affiliation(s)
- Jason Reed
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095, USA
| | - Bud Mishra
- Department of Computer Science and Mathematics, Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
| | | | | | - Joshua Troke
- Department of Pathology and the Center for Cell Control, an NIH Nanomedicine Development Center, UCLA, Los Angeles, CA 90095, USA
| | - Michael A Teitell
- Department of Pathology and the Center for Cell Control, an NIH Nanomedicine Development Center, UCLA, Los Angeles, CA 90095, USA
- California Nanosystems Institute (CNSI), Los Angeles, CA 90095, USA
| | - James K Gimzewski
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095, USA
- California Nanosystems Institute (CNSI), Los Angeles, CA 90095, USA
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Uenishi K, Morikawa H, Sudo A, Endo T. Cascade chemical transformation of five-membered cyclic dithiocarbonate in a networked polysiloxane layer on a silicate surface. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/pola.21859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Monticelli F, Osorio R, Toledano M, Tay FR, Ferrari M. In Vitro Hydrolytic Degradation of Composite Quartz Fiber-post Bonds Created by Hydrophilic Silane Couplings. Oper Dent 2006; 31:728-33. [PMID: 17153984 DOI: 10.2341/05-151] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Silane-based composite bonds are susceptible to hydrolytic degradation: interfacial water sorption induced by hydrolytic couplings may adversely affect their strength.
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Affiliation(s)
- Francesca Monticelli
- Department of Restorative Dentistry and Dental Materials, Policlinico Le Scotte, University of Siena, Siena, Italy.
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Yim H, Kent MS, Tallant DR, Garcia MJ, Majewski J. Hygrothermal degradation of (3-glycidoxypropyl)trimethoxysilane films studied by neutron and X-ray reflectivity and attenuated total reflection infrared spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:4382-92. [PMID: 16032851 DOI: 10.1021/la0474870] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Thin films of organosilanes have great technological importance in the areas of adhesion promotion, durability, and corrosion resistance. However, it is well-known that water can degrade organosilane films, particularly at elevated temperatures. In this work, X-ray and neutron reflectivity (XR and NR) were combined with attenuated total reflection infrared (ATR-IR) spectroscopy to study the chemical and structural changes within thin films of (3-glycidoxypropyl)trimethoxysilane (GPS) after exposure for various periods of time to air saturated with either D2O or H2O at 80 degrees C. For NR and XR, ultrathin (approximately 100 A) films were prepared by spin-coating. Both D2O and H2O provide neutron scattering contrast with GPS. Variations in the neutron scattering length density (SLD) profiles (a function of mass density and atomic composition) with conditioning time were measured after drying the samples out and also swelled with H2O or D2O vapor at room temperature. For samples that were dried out prior to measurement, little or no change was observed for H2O conditioning up to 3.5 days, but large changes were observed after 30 days of conditioning. The range of conditioning time for this structural change was narrowed to between 4 and 10 days with XR. The SLD profiles indicated that the top portion of the GPS film was transformed into a thick low-density layer after conditioning, but the bottom portion showed little structural change. A previous NR study of as-prepared GPS films involving swelling with deuterated nitrobenzene showed that the central portion of the film has much lower cross-link density than the region nearest the substrate. The present data show that the central portion also swells to a much greater extent with water and hydrolyzes more rapidly. The chemical degradation mechanism was identified by IR as hydrolysis of siloxane bonds. For ATR-IR, GPS films were prepared by dip-coating, which resulted in a greater and more variable thickness than for the spin-coated samples. The IR spectra revealed an increase in vicinal silanol generation over the first 3 days of conditioning followed by geminal silanol generation. Thus, the structural change detected by NR and XR roughly coincided with the onset of geminal silanol generation. Finally, little change in the reflectivity data was observed for films conditioned with D2O at 80 degrees C for 1 month. This indicates that hydrolysis of Si-O-Si is much slower with D2O than with H2O.
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Affiliation(s)
- H Yim
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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