Download or read book Surface Enhanced Raman Scattering and Electrochemical Characterization of Metal Electrode electrolyte Interfaces in Nonaqueous Systems PHD written by Aijin Shen and published by . This book was released on 1996 with total page 0 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 Dissertation Abstracts International written by and published by . This book was released on 1997 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrochemical Interfaces written by Héctor D. Abruña and published by . This book was released on 1991 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of the Electrochemical Interface by Surface Enhanced Raman Scattering written by Dipankar Roy and published by . This book was released on 1986 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tip enhanced Raman Spectroscopy on Electrochemical Systems written by Thomas Touzalin and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The in situ investigation of electrochemical interfaces structures at the nanoscale is a key element in the understanding of charge and electron transfer mechanisms e.g. in the fields of energy storage or electrocatalysis. This thesis introduces the implementation of tip-enhanced Raman spectroscopy (TERS) in liquid and in electrochemical conditions enabling the nanoscale analysis of electrified solid/liquid interfaces through the strong and local electric field enhancement at gold or silver scanning tunneling microscopy (STM) probes. The ability of TERS to image inhomogeneities in the coverage density of a self-assembled monolayer (SAM) through a layer of organic solvent on gold was demonstrated. A TERS-inspired analytical tool was also developed, based on a TERS tip used simultaneously as a single-hot spot surface-enhanced Raman spectroscopy (SERS) platform and as a microelectrode (EC tip SERS). The reduction of an electroactive SAM could then be monitored by electrochemical and in situ SERS measurements. In situ electrochemical STM-TERS was also evidenced through the imaging of local variations of the electric field enhancement on peculiar sites of a gold electrode with a lateral resolution lower than 8 nm. Finally TERS also demonstrated to be efficient in investigating the structure of organic layers grafted either by electrochemical reduction or spontaneously. This work is therefore a major advance for the analysis of functionalized surfaces.
Download or read book Surface Enhanced Raman Spectroscopy of Electrochemically Characterized Interfaces Transition Metal Isothiocyanate Adsorbates at Silver Adsorbates written by M. A. Tadayyoni and published by . This book was released on 1984 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-enhanced Raman (SER) spectra have been obtained at the silver-aqueous interface for nine Cr III, Co III, Ru II, and Rh III ammine or ethylenediamine complexes containing one or more thiocyanates as surface bridging groups. These complexes provide stereochemically well-defined adsorbates having at least one sulfur surface binding site but with electronic properties that differ substantially from thiocyanate itself. The dependence of the SER spectra were examined in each case over a potential range where the complexes are stable with respect to reduction or oxidation, and where the adsorbate coverage remained close to a monolayer. The adsorbate coverage could be evaluated in several cases from the faradaic charge required for one-electron reduction. SER spectra were obtained using a spectrograph-optical multichannel analyzer (OMA) as well as a conventional scanning spectrometer. This enabled the rapid reversible component of the SERS potential dependence to be separated from the irreversible signal decay associated with surface rearrangement. SERS bands due to metal ammine and internal ammine vibrations were observed in addition to those associated with internal thiocyanate and ligand-surface vibrations.
Download or read book Surface Enhanced Raman Spectroscopy of Electrochemically Characterized Interfaces Relations Between Raman Scattering Intensity and Surface Coverage for Simple Anionic Adsorbates written by M. J. Weaver and published by . This book was released on 1983 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-Enhanced Raman Scattering (SERS) obtained as a function of electrode potential for chloride, bromide, iodide, thiocyanate, azide, and cyanide adsorbed at roughened silver electrodes are compared with corresponding surface concentration-potential data extracted from differential capacitance measurements in order to examine the relation between SERS and surface coverage for these structurally simple adsorbates. After generating SERS by means of an oxidation-reduction cycle, it was found that altering the potential to a more negative value, where the adsorbate coverage fell below a monolayer, corresponded closely in most cases to the onset of a potential-dependent decay in the SERS intensity. Monitoring the potential dependence of the Raman intensity with an Optical Multi-channel Analyzer as well as with a conventional scanning spectrometer allowed a rapid reversible component of the potential dependence to be separated from an additional irreversible signal decay associated with the loss of Raman-active sites. The present results suggest that the adsorption energetics of the Raman-active surface sites do not differ substantially from those for the sites occupied by the majority of the adsorbate.
Download or read book Surface Enhanced Raman Scattering written by Ujjal Kumar Sur and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The steady and fast development of surface and interfacial science have set up innovative openings for new diagnostic probes for analytical characterization of the adsorbates and determination of the microscopic structure of surfaces and interfaces. Regrettably Raman spectroscopy, being a weak scattering surface phenomenon, had seized no part in it, until the discovery and development of Surface Enhanced Raman Scattering (SERS) in the early 1970's that has opened up broad research fields both in the physics and chemistry of interfaces. The discovery of SERS by Fleischmann and coworkers in 1974 at the University of Southampton, United Kingdom is closely connected with the electrochemical systems. They reported an extraordinary million-fold enhancement of weak Raman signal from pyridine molecules adsorbed onto electrochemically roughened silver electrode compared to that from free molecules in liquid environment. In early 1976, Richard P. Van Duyne and David Jeanmaire at Northwestern University observed the effect and in early 1977, M. G. Albrecht and J. A. Creighton reported similar observation. This review article deals with the development of SERS research with special importance is given to the fabrication of various SERS-active substrates, mechanism of SERS effect and its various potential applications ranging from sensors to biomedical applications.
Download or read book Spectroscopic Tools for the Analysis of Electrochemical Systems written by James McBreen and published by The Electrochemical Society. This book was released on 2002 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Enhanced Raman Scattering New Theoretical Approaches Materials and Strategies written by Ivano Alessandri and published by Frontiers Media SA. This book was released on 2020-03-25 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Surface Enhanced Raman Spectroscopic Study of the Electrode electrolyte Interface written by R. B. Lowry and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Enhanced Raman Scattering written by Richard Chang and published by Springer. This book was released on 2012-11-25 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would lead to a new understanding about the chemical identity, geome try, and bonding of adsorbed material at a level previously unacces sible. It is for these reasons that the last few years have brought an explosion of activity surrounding the exploitation of SERS. The search for the origines) of the anomalous enhancement has given rise to a research sub-activity of its own. Efforts to explain the en hancement have led to an increased understanding of the whole range of phenomena associated with the interaction of photons with adsor bates and metal surfaces.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1980 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Frontiers of Surface Enhanced Raman Scattering written by Yukihiro Ozaki and published by John Wiley & Sons. This book was released on 2014-02-19 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive presentation of Surface-Enhanced Raman Scattering (SERS) theory, substrate fabrication, applications of SERS to biosystems, chemical analysis, sensing and fundamental innovation through experimentation. Written by internationally recognized editors and contributors. Relevant to all those within the scientific community dealing with Raman Spectroscopy, i.e. physicists, chemists, biologists, material scientists, physicians and biomedical scientists. SERS applications are widely expanding and the technology is now used in the field of nanotechnologies, applications to biosystems, nonosensors, nanoimaging and nanoscience.
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observation of Surface Enhanced Raman Scattering for Transition Metal Hexaammine Cations at the Outer Helmholtz Plane Implications for Enhancement Mechanisms at Electrochemical Interfaces written by M. A. Tadayyoni and published by . This book was released on 1983 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent observation of surface-enhanced Raman scattering (SERS) for a variety of adsorbates at silver in electrochemical and gas-phase environments has generated a plethora of theoretical models to account for the remarkable (ca. 1,000,000 fold) observed enhancement of the Raman scattering intensities. These models can be divided into those demanding only the presence of the Raman scatterer at or close to the metal surface ('physical models'), and those requiring specific adsorbate-surface interactions ('chemical models'). Prompted in part by the especially intense SERS seen for specifically adsorbed species at silver electrodes, a widely held viewpoint is that the enhancement is due in part to chemical interactions between the Raman scatterer and the metal surface, possibly involving as adsorbate-adatom 'complex'. The report examines SERS of inorganic adsorbates at silver-aqueous interfaces. One objective is to examine systematically how the SER spectra are influenced by the nature of the adsorbate-surface interactions. A valuable class of adsorbates for this purpose is provided by substitutionally-inert Cr(III), Co(III), Ru(III) and Os(III) ammine complexes containing ligands such as thiocyanate, bromide, or pyrazine that bind strongly to silver electrodes.
