Light Scattering Studies of Molecular Dynamics in Molecular Crystals, Liquid Crystals and Polymers for Applications in Chemical Defense

Light Scattering Studies of Molecular Dynamics in Molecular Crystals, Liquid Crystals and Polymers for Applications in Chemical Defense PDF Author: Elliot R. Bernstein
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

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Book Description
A total of 16 papers have appeared in the literature dealing with both the theoretical and experimental (light scattering) investigation of phase transitions and critical phenomena in simple molecular solids. New Brillouin scattering data have been obtained for benzil single crystals near the phase transition at 83.5K. A mean field approach to the dynamics of structural phase transitions in molecular crystals has been developed. Brillouin scattering study of the successive phase transitions in methmmonium iron chloride. In addition to the magnetic transition at lwo temperature, this system also possesses successive structural phase transitions. These have been studied by means of lattice dynamics and far infrared spectroscopy, birefringenence, x-ray and neutron diffraction, specific heat and ultrasonic sound velocity measurements, and ultrasonic attentuation measurements. Also pursued were high pressure Raman, Brillouin, and Rayleigh scattering studies of benzene in a diamond anvil cell.

Light Scattering Studies of Molecular Dynamics in Molecular Crystals, Liquid Crystals and Polymers for Applications in Chemical Defense

Light Scattering Studies of Molecular Dynamics in Molecular Crystals, Liquid Crystals and Polymers for Applications in Chemical Defense PDF Author: Elliot R. Bernstein
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

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Book Description
A total of 16 papers have appeared in the literature dealing with both the theoretical and experimental (light scattering) investigation of phase transitions and critical phenomena in simple molecular solids. New Brillouin scattering data have been obtained for benzil single crystals near the phase transition at 83.5K. A mean field approach to the dynamics of structural phase transitions in molecular crystals has been developed. Brillouin scattering study of the successive phase transitions in methmmonium iron chloride. In addition to the magnetic transition at lwo temperature, this system also possesses successive structural phase transitions. These have been studied by means of lattice dynamics and far infrared spectroscopy, birefringenence, x-ray and neutron diffraction, specific heat and ultrasonic sound velocity measurements, and ultrasonic attentuation measurements. Also pursued were high pressure Raman, Brillouin, and Rayleigh scattering studies of benzene in a diamond anvil cell.

AFOSR Chemical & Atmospheric Sciences Program Review

AFOSR Chemical & Atmospheric Sciences Program Review PDF Author: United States. Air Force. Directorate of Chemical and Atmospheric Sciences
Publisher:
ISBN:
Category : Atmospheric chemistry
Languages : en
Pages : 126

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Light Scattering from Macromolecular Systems - Molecular Crystals and Polymers

Light Scattering from Macromolecular Systems - Molecular Crystals and Polymers PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 32

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The research objectives of this grant are to (1) characterize phase transitions theoretically and experimentally in molecular crystal systems, (2) use the above understanding gained by light scattering studies and theoretical interpretation to apply to the more complex system of lyotropic liquid crystals, and (3) knowledge gained on the model systems of increasing complexity is then applied to polymer liquid crystals and solid polymers as observed by laser light scattering techniques. Objective one has been definitely achieved as can be seen from the number of papers written in the last few years. Systems to have been experimentally and theoretically discussed are: trioxane, triazine, benzil, and chloranil. Others still to be investigated are: biphenyl, urea, thiourea, and hexamethyl benzene. Studies of lyotropic liquid crystals (sodium decyl sulfate, sodium sulfate, decanol, water) have been progressed to the point at which we will be reporting this data shortly. The major findings are: a number of phase transitions occur between 20 and 60 C; these transitions evidence strong critical behavior and long correlation times for fluctuations; and liquid crystals can be studied by light scattering in a unique and meaningful manner. Finally, some polymer studies were started which will be continued into the coming contract period. Spectra of solid powders, ribbons, and liquid crystals of PBT and solid PBO were obtained.

Applications of Dynamic Light Scattering in Chemical Engineering

Applications of Dynamic Light Scattering in Chemical Engineering PDF Author: Kirtland L. Linegar
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Dynamic Light Scattering

Dynamic Light Scattering PDF Author: Bruce J. Berne
Publisher: Courier Corporation
ISBN: 0486320243
Category : Science
Languages : en
Pages : 482

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Book Description
Lasers play an increasingly important role in a variety of detection techniques, making inelastic light scattering a tool of growing value in the investigation of dynamic and structural problems in chemistry, biology, and physics. Until the initial publication of this work, however, no monograph treated the principles behind current developments in the field.This volume presents a comprehensive introduction to the principles underlying laser light scattering, focusing on the time dependence of fluctuations in fluid systems; it also serves as an introduction to the theory of time correlation functions, with chapters on projection operator techniques in statistical mechanics. The first half comprises most of the material necessary for an elementary understanding of the applications to the study of macromolecules, or comparable sized particles in fluids, and to the motility of microorganisms. The study of collective (or many particle) effects constitutes the second half, including more sophisticated treatments of macromolecules in solution and most of the applications of light scattering to the study of fluids containing small molecules.With its wide-ranging discussions of the many applications of light scattering, this text will be of interest to research chemists, physicists, biologists, medical and fluid mechanics researchers, engineers, and graduate students in these areas.

Light Scattering in Liquids and Macromolecular Solutions

Light Scattering in Liquids and Macromolecular Solutions PDF Author: V. Degiorgio
Publisher: Springer Science & Business Media
ISBN: 1461591856
Category : Science
Languages : en
Pages : 293

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Book Description
This volume contains most of the papers presented at the "Workshop on Quasielastic Light Scattering Studies of Fluids and Macromolecular Solutions" held at CISE, Segrate (Milano), Italy, from 11 to 13 May, 1979. Quasielastic light scattering (also called self-beating spectroscopy or intensity correlation spectroscopy) is the technique, introduced by Benedek and coworkers and by Cummins and coworkers about 15 years ago, by which dynamical information about a scattering medium is obtained through the measurement of the power spectrum (or the intensity correlation function) of the laser light scattered from the medium. The technique received in the early seventies a considerable impulse from the development of real-time fast digital correlators. The aim of the Workshop was to bring together a selected number of researchers in order to discuss recent developments in quasielastic light scattering and related optical methods and to report about new applications of the technique in physics, chemistry and biology. The first two days of the meeting were devoted to the oral presentations of papers. In the third day an informal session was held which included a very lively and thorough discussion of the highlights of the Workshop. Most part of the technical problems were debated during the informal session and during the subsequent visits to the light scattering laboratory in CISE.

Government Reports Announcements & Index

Government Reports Announcements & Index PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1796

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Introduction to Dynamic Light Scattering by Macromolecules

Introduction to Dynamic Light Scattering by Macromolecules PDF Author: Kenneth S Schmitz
Publisher: Elsevier
ISBN: 0323140351
Category : Science
Languages : en
Pages : 470

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Book Description
An Introduction to Dynamic Light Scattering by Macromolecules provides an introduction to the basic concepts of dynamic light scattering (DLS), with an emphasis on the interpretation of DLS data. It presents the appropriate equations used to interpret DLS data. The material is presented in order of increasing complexity of the systems under examination, ranging from dilute solutions of noninteracting particles to concentrated multicomponent solutions of strongly interacting particles and gels. Problems are presented at the end of each chapter to emphasize these concepts. Since a major emphasis of this textbook is the interpretation of DLS data obtained by polarized light scattering studies on macromolecular solutions, the results of complementary experimental techniques are also presented in order to gain insight into the dynamics of these systems. This textbook is intended for (1) advanced undergraduate students and graduate students in the chemical, physical, and biological sciences; (2) scientists who might wish to apply DLS methods to systems of interest to them but who have no formal training in the field of DLS; and (3) those who are simply curious as to the type of information that might be obtained from DLS techniques.

Dynamic Light Scattering

Dynamic Light Scattering PDF Author: R. Pecora
Publisher: Springer Science & Business Media
ISBN: 1461323894
Category : Science
Languages : en
Pages : 429

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Book Description
In the twenty years since their inception, modern dynamic light-scattering techniques have become increasingly sophisticated, and their applications have grown exceedingly diverse. Applications of the techniques to problems in physics, chemistry, biology, medicine, and fluid mechanics have prolifer ated. It is probably no longer possible for one or two authors to write a monograph to cover in depth the advances in scattering techniques and the main areas in which they have made a major impact. This volume, which we expect to be the first of aseries, presents reviews of selected specialized areas by renowned experts. It makes no attempt to be comprehensive; it emphasizes a body of related applications to polymeric, biological, and colloidal systems, and to critical phenomena. The well-known monographs on dynamic light scattering by Berne and Pecora and by Chu were published almost ten years ago. They provided comprehensive treatments of the general principles of dynamic light scat tering and gave introductions to a wide variety of applications, but natu rally they could not treat the new applications and advances in older ones that have arisen in the last decade. The new applications include studies of interacting particles in solution (Chapter 4); scaling approaches to the dynamics of polymers, including polymers in semidilute solution (Chapter 5); the use of both Fabry-Perot interferometry and photon correlation spectroscopy to study bulk polymers (Chapter 6); studies of micelIes and microemulsions (Chapter 8); studies of polymer gels (Chapter 9).

Light Scattering Studies of Molecular Dynamics in Solutions and Liquids

Light Scattering Studies of Molecular Dynamics in Solutions and Liquids PDF Author: M. Whittle
Publisher:
ISBN:
Category :
Languages : en
Pages :

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