Download or read book Characterization of Polymer Interphases Using Surface Enhanced Raman Scattering written by F. J. Boerio and published by . This book was released on 1990 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-enhanced Raman scattering (SERS) and reflection-absorption infrared spectroscopy (RAIR) were used to determine the molecular structure of interphases between polymers and metal substrates. An interesting example was provided by pyromellitic diimide (PMDI), a model compound for polyimides, and silver substrates. Normal Raman spectra of PMDI were characterized by strong bands near 1772, 1370, 760, and 655 1/cm and medium intensity bands near 1630 and 1205 1/cm were weak in SERS spectra obtained from films of PMDI spin-coated onto silver island films while those near 1370 and 1205 1/cm and a new band near 685 1/cm were strongest. Differences between the normal Raman and SERS spectra were related to orientation effects indicating that PMDI was absorbed onto silver with a vertical conformation in which the rings were perpendicular to the surface and one imide group was in contact with the surface. Keywords: Polymer interphases, Surface enhanced raman scattering, Molecular structures, Thin films, RAIR, SERS, DD Form 1473, Spectroscopy. (JG).
Download or read book Non Destructive Characterization of Polymer Interphases and In Situ Polymerization Using Surface Enhanced Raman Scattering written by and published by . This book was released on 1992 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The molecular structure of interphases between substrates such as metals and graphite and polymer systems cured against them was determined using surface analysis techniques such as reflection-absorption infrared spectroscopy, X-ray photoelectron spectroscopy, and surface enhanced Raman scattering. It was found that the substrates had a significant effect on the molecular structure of the interphase and that the molecular structure of the interphase was significantly different from that of the bulk polymers. In some cases, there was a vigorous reaction between components of the polymer system and the substrate. Thus, when an acrylic adhesive was cured against silver substrates, o-benzoic sulfimide, a component of the curing system, segregated to the interface and reacted with metal ions to form salts. The salts reacted with a peroxide in the curing system to form radicals which initiated polymerization. In other cases, components of the polymer preferentially adsorbed onto the substrate. Thus the curing agent dicyandiamide was adsorbed at the interface between an epoxy and silver. The behavior of polyamic acids was strongly affected by substrates they were deposited on.
Download or read book Non Destructive Characterization of Polymer Metal Interphases Using Surface Enhanced Raman Scattering written by F. J. Boerio and published by . This book was released on 1990 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhanced Raman scattering (SERS) is an analytical technique in which the Raman scattering cross sections of molecules adsorbed onto the roughened surfaces of certain metals are enhanced by as much as six orders of magnitude compared to their value for normal Raman scattering. The mechanisms are associated with the large electric fields that can be induced at the surfaces of metal particles having small radii of curvature and with formation of charge transfer complexes between the adsorbed molecules and the substrate. Enhancement due to the charge transfer mechanism is obtained only for molecules immediately adjacent to the surface but enhancement due to the electromagnetic mechanism may extend several monolayers away from the surface. Since normal Raman scattering by polymers is weak and scattering by molecules adjacent to the substrate is strongly enhanced, SERS can be used for nondestructive characterization of interfaces between polymer films and metals. Silver, Polymers, Materials, Acrylic monomer, Cumene, Hydroperoxide(CHP), Acetylphenylhydrazine(APH), Saccharin, Adhesives, Pyromellitic diimide (PMDI), Surface properties. (JG).
Download or read book Characterization of Polymer Surfaces and Interfaces Using Surface enhanced Raman Scattering written by Pel-Pel Hong and published by . This book was released on 1992 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Interfaces Between Polymers and Substrates Using Surface enhanced Raman Scattering written by Wen-Hsien Tsai and published by . This book was released on 1991 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non Destructive Characterization of Polymer Metal Interfaces Using Surface Enhanced Raman Scattering SERS written by F. J. Boerio and published by . This book was released on 1990 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-enhanced Raman scattering (SERS) is an analytical technique in which the Raman scattering cross-sections of molecules adsorbed onto the roughened surfaces of certain metals are enhanced by as much as six orders of magnitude compared to their value for normal Raman scattering. Many models have been proposed to explain SERS, but it is now considered that most of the enhancement is related to two mechanisms. The first is associated with the large electric fields that can be induced at the surfaces of metal particles having small radii of curvature. The second is associated with formation of charge-transfer complexes between the adsorbed molecules and the substrate. Enhancement due to the charge transfer mechanism is obtained only for molecules immediately adjacent to the surface, but enhancement due to electromagnetic mechanism may extend several monolayers away from the surface. Considering that normal Raman scattering by polymers is weak and that scattering by molecules adjacent to the substrate is strongly enhanced, it is evident that SERS can be used for non-destructive characterization of interfaces between polymer films and metals as long as the films are not so thick that scattering by the bulk of the film is comparable in intensity to SERS from the interface. Keywords: DD Form 1473, Nondestructive characterization, Polymer/Metal interfaces, Surface-enhanced raman scattering, SERS, Adsorption, Silver, Acrylic adhesive system.
Download or read book Characterization of Interphases Between PMDA 4 BDAF Polyimides and Silver Substrates Using Surface Enhanced Raman Scattering and Reflection Absorption Infrared Spectroscopy written by and published by . This book was released on 1990 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-enhanced Raman scattering (SERS) and reflection-absorption infrared spectroscopy (RAIR) were used to determine the molecular structure of interphases formed by curing the polyamic acid of pyromellitic dianhydride (PMDA) and 2,2-BIS(4-(4-aminophenoxy)-phenyl)-hexafluoropropane (4-BDAF) against silver substrates. SERS spectra of the cured polymer were more simular to the SERS spectra of the polyamic acid than to the normal Raman spectrum of the polymide, indicating that curing of the polymer was inhibited by interaction of the polyamic acid with the substrate. Thus, the strongest band in the normal RAMAN spectrum of the polymide was near 1406 cm-1 and was assigned to the CNC axial stretching mode.
Download or read book Structure and Properties of Polymer Interphases written by F. James Boerio and published by . This book was released on 1988 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The molecular structure of interphases between polymer systems and metal substrates was determined by using x-ray photoelectron spectroscopy (XPS), reflection-absorption infrared spectroscopy (RAIR), and attenuated total-reflection infrared spectroscopy (ATR) to characterize the failure surfaces of double cantilever beam adhesive joints prepared by curing beams of epoxies against metal beams. The structure of the interphases depended strongly on the curing agent, metal substrate, and use of a silane primer on the substrate. When joints were prepared by curing an epoxy with a tertiary amine curing agent at 75 C against a steel substrate primed with a dilute aqueous solution of gamma-aminopropyltriethoxy-silane, there was little reaction between the primer and adhesive and failure occurred near the primer/adhesive interface. The interphase consisted of low molecular weight siloxane oligomers in which the amino groups formed bicarbonates with water and carbon dioxide absorbed from the atmosphere. When similar joints were cured at 150 C, the bicarbonates dissociated, enabling the adhesive and primer to react, and shifting the locus of failure near the primer/adherend interface or into the epoxy. The use of surface-enhanced Raman scattering (sers) for non-destructive characterization of interphases between polymers and metals was demonstrated. (aw).
Download or read book Non destructive Characterization of Polyimide silver Interphases Using Surface enhanced Raman Scattering written by Jin-Ter Young and published by . This book was released on 1990 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Surfaces and Interfaces Characterization Modification and Application written by Kash L. Mittal and published by CRC Press. This book was released on 2023-01-06 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymeric materials are used for a legion of applications in a wide array of technological areas, and their proper surface/interface characteristics are of cardinal importance for their applications. Therefore, the need to characterize polymer surfaces/interfaces and their suitable modification to impart desired characteristics is quite patent. This book chronicles the proceedings of the Symposium on Polymer Surfaces and Interfaces: Characterization, Modification and Application held as a part of the Society of Plastics Engineers Annual Technical Conference, Boston, May 7--11, 1995. The articles in this book address many aspects of polymer surfaces and interfaces. Topics covered include: various ways (chemical, photochemical, laser, flame, corona) to modify polymer surfaces; modification of contact lens surfaces; various ways to analyze/characterize polymer surfaces; metal/polymer interfaces; metal/polyimide adhesion; metal/self-assembled organic monolayer interfaces; polymer alignment layers for liquid crystals; alignment of liquid crystal surfaces; polyimide alignment layers; molecular re-orientation of polymer surfaces; plasma polymerized organic coatings; epoxy/fiber interphase; epoxy underfill materials for packaging integrated circuits; transport in polymers; polymer miscibility; and cell adhesion.
Download or read book Non Destructive Characterization of Polyimide Copper and Polyimide Gold Interphases Using Surface Enhanced Raman Scattering and Reflection Absorption Infrared Spectroscopy written by and published by . This book was released on 1992 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The molecular structure of interfaces formed by curing the polyamic acid of pyromellitic dianhydride (PMDA) and oxydianiline (ODA) against copper and gold substrates was determined using surface-enhanced Raman scattering (SERS) and reflection-absorption infrared spectroscopy (RAIR). It was found that acid groups of the polyamic acid reacted with metal ions on the substrates to form carboxylate salts when the polyamic acid was spin coated onto metal substrates. Formation of carboxylates on the copper surface extended several hundred angstroms into the polyamic acid films, while only trace levels of carboxylates were formed on the gold surface. Formation of carboxylate salts suppressed the curing of polyamic acid on copper substrates. However, the degree of curing of the polyamic acid was high on gold surfaces. These results were compared to our previous work concerned with the molecular structure of interfaces between PMDA/ODA.
Download or read book Polymer Characterization Interdisciplinary Approaches written by Clara D. Craver and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical and spectroscopic methods have been used jointly for characterization of polymers for at least four decades. Yet, new techniques permit increasingly refined determination of polymer chemistry and morphol ogy_ The correlation of this knowledge with physical properties of polymers is helpful to planned synthesis of new products. The most prominent spectroscopic techniques through the forties and fifties were infrared and ultraviolet spectroscopy. Nuclear magnetic resonance, electron spin resonance and MOssbauer spectroscopy started making sig nificant contributions to polymer chemistry in the early sixties. Still more recently fluorescence spectroscopy and laser Raman spectroscopy have become readily appli cable to polymers and are contributing significantly to the understanding of the relationship between polymer structure and properties. Determination of the distribution of monomer se quences by molecular size has become possible through combined gel permeation chromatography and spectroscopic analysis. Fragments of polymers from chemical break down or from pyrolysis are further fractionated and structurally analyzed. The relationship between the chemistry of polymers and performance can be determined from changes in chemical structure and orientation after curing, degradation, or physical or thermal manipulation of the polymers.
Download or read book Polymer Inorganic Interfaces Volume 304 written by Robert L. Opila and published by . This book was released on 1993-09-17 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MRS Symposium Proceeding series is an internationally recognised reference suitable for researchers and practitioners.
Download or read book Interface Interphase in Polymer Nanocomposites written by Anil N. Netravali and published by John Wiley & Sons. This book was released on 2016-11-29 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant research has been done in polymeric nanocomposites and progress has been made in understanding nanofiller-polymer interface and interphase and their relation to nanocomposite properties. However, the information is scattered in many different publication media. This is the first book that consolidates the current knowledge on understanding, characterization and tailoring interfacial interactions between nanofillers and polymers by bringing together leading researchers and experts in this field to present their cutting edge research. Eleven chapters authored by senior subject specialists cover topics including: Thermodynamic mechanisms governing nanofiller dispersion, engineering of interphase with nanofillers Role of interphase in governing the mechanical, electrical, thermal and other functional properties of nanocomposites, characterization and modelling of the interphase Effects of crystallization on the interface, chemical and physical techniques for surface modification of nanocellulose reinforcements Electro-micromechanical and nanoindentation techniques for interface evaluation, molecular dynamics (MD) simulations to quantify filler-matrix adhesion and nanocomposite mechanical properties.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1990 with total page 1120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopic Techniques for Polymer Characterization written by Yukihiro Ozaki and published by John Wiley & Sons. This book was released on 2022-03-14 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: An insightful exploration of cutting-edge spectroscopic techniques in polymer characterization In Spectroscopic Techniques for Polymer Characterization: Methods, Instrumentation, Applications, a team of distinguished chemists delivers a comprehensive exploration of the vast potential of spectroscopic characterization techniques in polymer research. The book offers a concise outline of the principles, advantages, instrumentation, experimental techniques, and noteworthy applications of cutting-edge spectroscopy. Covering a wide range of polymers, from nylon to complex polymeric nanocomposites, the author presents recent developments in polymer science to polymer, analytical, and material chemists, assisting them in keeping track of the progress in modern spectroscopy. Spectroscopic Techniques for Polymer Characterization contains contributions from pioneers in modern spectroscopic techniques from around the world. The included materials bridge the gap between spectroscopists, polymer scientists, and engineers in academia and industry. The book also offers: A thorough introduction to the progress in spectroscopic techniques, including polymer spectroscopy and near-infrared spectroscopy Comprehensive explorations of topical polymers studied by spectroscopy, including polymer thin films, fluoropolymers, polymer solutions, conductive polymers Practical discussions of infrared imaging, near-infrared imaging, two-dimensional correlation spectroscopy, and far-ultraviolet spectroscopy In-depth examinations of spectroscopic studies of weak hydrogen bonding in polymers Spectroscopic Techniques for Polymer Characterization: Methods, Instrumentation, Applications is a must-read reference for polymer, analytical, and physical chemists, as well as materials scientists and spectroscopists seeking a one-stop resource for polymer characterization using spectroscopic analyses.
