Download or read book Study of transport properties and structure of extended chain polymers written by R. Edward Barker (Jr) and published by . This book was released on 1985 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: The broad objective of the work was to relate charge, heat, and mass transport in the Air Force's extended chain polymers (especially poly-para-phenylene benzobisthiazole PBT) to other electrical, thermal, mechanical nad microstructural properties of the polymers and also to compare these very unusual, highly anisotropic Air Force materials with other materials when it is scientifically relevant or when potential applications may be involved. Special techniques were developed for making transport-property determinations on samples in the form of thin fibers and small area films. Two types of miniature cells were developed in the study of PBT transport properties. A very promising area of the research relates to an anisotropic version of the Barker-Sharbaugh weak electrolyte model for ionic conduction in polymers. A new technique which has been termed the diffusion controlled-differential current (DCDC) method evolved from experiments related to the weak electrolyte model. This DCDC-technique looks promising as a new analytical tool. The results for PBT turned out to be especially interesting because the ratio of ionic conductivities parallel and perpendicular to the chain axis was very large (100,000 at 300 K) and temperature dependent (smaller ratio at a higher temperature). Special techniques for the thermal conductivity allowed the axial and perpendicular thermal conductivities to be determined.
Download or read book Study of Transport Properties and Structure of Extended Chain Polymers Diffusion and Solubility of Gases written by R. Edward Barker (Jr) and published by . This book was released on 1985 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of the transport properties in extended chain polymers has added to the understanding of relations between their macroscopic and microscopic properties. There was a need to determine the extent to which a new class of high strength extended chain polymers absorb various vapors and how the vapor moves within the materials, which have a highly anisotropic fibrous morphology. The main polymer studied as a representative of the class is poly p-phenylene benzobisthiazole (PPBT). An abnormally large heat of sorption (solution) and paradoxical data from two experimental systems with somewhat different conditions are attributed to a large volume fraction of microcavities in PPBT. This hypothesis was shown to be consistent by using the theory of dual sorption. A statistical mechanical model due to diBenedetto was modified to correlate the activation energy with rotation energy and to make possible the prediction of the parallel diffusion coefficient.
Download or read book Study of transport properties and structure of extended chian polymers written by R. Edward Barker and published by . This book was released on 1985 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of transport preperties and structure of extended chain polymers written by R. Edward Barker and published by . This book was released on 1985 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure And Transport Properties In Organized Polymeric Materials written by Emo Chiellini and published by World Scientific. This book was released on 1998-03-19 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This multi-authored book includes selected contributions reviewing the results achieved in the synthesis and characterization of organized polymeric materials. The focus is on competitive materials with liquid crystalline or electroconductive properties. The fine tuning of the properties offered by advanced chemical synthesis has been investigated by a large number of state-of-the-art techniques, including both microscopic (ESR, NMR, dielectrometry, fluorescence, IR, Raman spectroscopy) and macroscopic (calorimetric, mechanical) methodologies. The book also provides an updated coverage of the most challenging applications of organized polymers as functional materials in the fields of electrooptical devices, information retrieval and organic electroconductors.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AFOSR Chemical Atmospheric Sciences Program Review written by United States. Air Force. Directorate of Chemical and Atmospheric Sciences and published by . This book was released on with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical techniques for the study of sorption electrical properties and interfacial effects in ordered polymers written by R. Edward Barker and published by . This book was released on 1986 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Transport Properties in Organized Polymeric Materials written by Emo Chiellini and published by World Scientific. This book was released on 1997 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This multi-authored book includes selected contributions reviewing the results achieved in the synthesis and characterization of organized polymeric materials. The focus is on competitive materials with liquid crystalline or electroconductive properties. The fine tuning of the properties offered by advanced chemical synthesis has been investigated by a large number of state-of-the-art techniques, including both microscopic (ESR, NMR, dielectrometry, fluorescence, IR, Raman spectroscopy) and macroscopic (calorimetric, mechanical) methodologies. The book also provides an updated coverage of the most challenging applications of organized polymers as functional materials in the fields of electrooptical devices, information retrieval and organic electroconductors.
Download or read book Transport Properties in Polymers written by Jiri Stastna and published by CRC Press. This book was released on 1995-03-01 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the Authors Introduction Diffusion is one of the few manageable nonequilibrium pro- cesses during which matter is transported through a system. Traditionally, diffusion is studied in physical chemistry; however, the fundamental understanding of diffusion processes is not possible without involving statistical physics. Diffusion in disordered systems, such as in polymers, has sometimes unexpected features, the nature of which has not yet been determined. Since modern technology involves more and more complex materials which rely on a subtle balance of microscopic effects, the understanding of diffusion processes in these materials is of paramount importance from the practical point of view. A renewed interest in the basic principles of diffusion is a direct result of new experimental data. This was a contributing factor in the preparation of this text. In the first chapter, the phenomenological thermodynamic basics of diffusion is reviewed, and the diffusion equation is derived from the principles of irreversible thermodynamics. The basic mathematical apparatus for solving diffusion equations is reviewed in the second chapter. The third chapter deals mainly with the vast amount of experimental data dealing with diffusion in polymers. . . . A reader interested in particular polymeric systems can use the . . . material as a useful introduction. The last chapter contains basic information concerning random walks and their application to the diffusion in disordered systems. The theory of random walks is widely used in polymer physics where it is usually combined with statistical mechanics to formulate various models of polymeric systems. Finally, useful mathematical formulas and references to the original sources of some mathematical methods are [provided] in the appendices. Some physical constants associated with several polymer solvent systems are also presented.
Download or read book Recent Research Accomplishments of the Air Force Office of Scientific Research written by United States. Air Force. Office of Scientific Research and published by . This book was released on 1989 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Air Force Research Objectives written by United States. Air Force. Office of Aerospace Research and published by . This book was released on with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials and Methods for Industrial Wastewater and Groundwater Treatment written by S. K. Nataraj and published by John Wiley & Sons. This book was released on 2024-09-18 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: An expert synthesis of the latest materials and methods with applications for groundwater and wastewater treatment Materials and Methods for Industrial Wastewater and Groundwater Treatment delivers an up-to-date discussion of the materials and methods being used to address the problem of pollutants in industrial wastewaters and groundwater. The book describes innovative new materials with significant potential to emerge as a next-generation solution in the water treatment space. Cutting-edge research is synthesized into these novel materials and methods and case studies demonstrate real-world applications of new solutions for water treatment. Readers will also find: A thorough introduction to new materials and techniques for treating wastewater and groundwater to remove pollutants Comprehensive explorations of the latest research on commercially viable methods for treating wastewater and groundwater Case studies highlighting the practical application of novel methods and materials as next-generation solutions for water treatment Perfect for industrial chemists, environmental and material researchers and supervisors, and consulting and design engineers in wastewater treatment plants, Materials and Methods for Industrial Wastewater and Groundwater Treatment will also benefit design professionals, materials scientists, and environmental engineers with an interest in nanomaterial applications to wastewater treatments.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1986 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book OAR written by and published by . This book was released on 1969 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Chains written by Régine Penzkofer and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physical properties of a polymer are strongly dependent on the size or length of the polymer chain. As chain length is increased, melting and boiling temperatures increase quickly. Impact resistance also tends to increase with chain length, as does the viscosity, or resistance to flow, of the polymer in its melted state. In this book, the authors present topical research in the study of the structure, physical properties and industrial uses of polymer chains. Topics discussed include the flexibility of polyheteroarylenes and the effect on several physical properties of these polymers; aliphatic polyester-based nanocomposites; bioplastic-based blends; interactions in small permeants in polymeric matrices; the role of polymer chain ends in plasma surface modification and pre-ceramic polymer chains.
Download or read book Structure and Dynamics of Confined Polymers written by John J. Kasianowicz and published by Springer Science & Business Media. This book was released on 2002-07-31 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are essential to biology because they can have enough stable degrees of freedom to store the molecular code of heredity and to express the sequences needed to manufacture new molecules. Through these they perform or control virtually every function in life. Although some biopolymers are created and spend their entire career in the relatively large free space inside cells or organelles, many biopolymers must migrate through a narrow passageway to get to their targeted destination. This suggests the questions: How does confining a polymer affect its behavior and function? What does that tell us about the interactions between the monomers that comprise the polymer and the molecules that confine it? Can we design and build devices that mimic the functions of these nanoscale systems? The NATO Advanced Research Workshop brought together for four days in Bikal, Hungary over forty experts in experimental and theoretical biophysics, molecular biology, biophysical chemistry, and biochemistry interested in these questions. Their papers collected in this book provide insight on biological processes involving confinement and form a basis for new biotechnological applications using polymers. In his paper Edmund DiMarzio asks: What is so special about polymers? Why are polymers so prevalent in living things? The chemist says the reason is that a protein made of N amino acids can have any of 20 different kinds at each position along the chain, resulting in 20 N different polymers, and that the complexity of life lies in this variety.
