Multicomponent Diffusion and Phase Separation in Asymmetric Ternary Polymer Systems PDF Download

Author: Abdulrahman A. Alfarraj
Publisher: ProQuest
ISBN: 9780549286608
Category : Chemical and biological engineering
Languages : en
Pages : 214

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Book Description

Author: Gregory Foley
Publisher:
ISBN:
Category : Diffusion
Languages : en
Pages : 226

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Author: Chen Kuang
Publisher:
ISBN:
Category : Polymers
Languages : en
Pages : 154

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Book Description
Phase separation in complex fluids such as polymers has been the subject of several experimental and theoretical studies in recent years. Understanding the phase separation mechanisms and controlling morphological evolution are very important for designing various advanced materials with novel mechanical, optical, electrical, and transport properties. In polymer blends, dynamic asymmetry is induced by a large difference in glass transition temperature. In this work, phase separation behavior of ternary blends of polystyrene/poly(vinyl methyl ether)/polyisoprene, PS/PVME/PI, and polystyrene/poly(vinyl methyl ether)/poly(ethyl methacrylate), PS/PVME/PEMA are investigated. Ternary blends of PS/PVME/PI and PS/PVME/PEMA exhibit complex phase separation behavior since PS and PVME have a lower critical solution temperature (LCST) behavior, while PI and PS (or PVME), PEMA and PS (or PVME) have upper critical solution temperature (UCST) behavior. 2D and 3D phase diagrams for these two ternary systems were plotted by both Flory-Huggins incompressible and regular solution compressible models. Casting the solutions of PS/PVME/PI and PS/PVME/PEMA blends form two phase-separated domains in most compositions: (i) PI-rich or PEMA rich, and (ii) PS/PVME-rich. Post-annealing of such samples leads to the second-stage phase separation due to unfavorable interaction of PS and PVME at temperatures about 100°C. Such behavior that is observed for the first time provides a new potential method for making different morphologies with the same system by changing annealing parameters and composition. Washing one polymer at a time using a selective solvent is used to study the morphology of ternary blends. Optical microscopy and scanning electron microscopy are used to study the kinetics and morphology of viscoelastic phase separation (VPS) in ternary blends.

Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 902

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Author: Redouane Borsali
Publisher: Springer Science & Business Media
ISBN: 140204464X
Category : Science
Languages : en
Pages : 1490

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Book Description
This 2-volume set includes extensive discussions of scattering techniques (light, neutron and X-ray) and related fluctuation and grating techniques that are at the forefront of this field. Most of the scattering techniques are Fourier space techniques. Recent advances have seen the development of powerful direct imaging methods such as atomic force microscopy and scanning probe microscopy. In addition, techniques that can be used to manipulate soft matter on the nanometer scale are also in rapid development. These include the scanning probe microscopy technique mentioned above as well as optical and magnetic tweezers.

Author:
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 184

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Author: Rahul Saxena
Publisher:
ISBN:
Category :
Languages : en
Pages : 390

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Book Description

Author: Lawrence K. Wang
Publisher: Springer Science & Business Media
ISBN: 1597452785
Category : Science
Languages : en
Pages : 728

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Book Description
In this essential new volume, Volume 13: Membrane and Desalination Technologies, a panel of expert researchers provide a wealth of information on membrane and desalination technologies. An advanced chemical and environmental engineering textbook as well as a comprehensive reference book, this volume is of high value to advanced graduate and undergraduate students, researchers, scientists, and designers of water and wastewater treatment systems. This is an essential part of the Handbook of Environmental Engineering series, an incredible collection of methodologies that study the effects of pollution and waste in their three basic forms: gas, solid, and liquid. Chapters adopt the series format, employing methods of practical design and calculation illustrated by numerical examples, including pertinent cost data whenever possible, and exploring in great detail the fundamental principles of the field. Volume 13: Membrane and Desalination Technologies is an essential guide for researchers, highlighting the latest developments in principles of membrane technology, membrane systems planning and design, industrial and municipal waste treatments, desalination requirements, wastewater reclamation, biofiltration, and more.

Author: R. J. Roe
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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Book Description
In this project a number of polymer blend systems were studied to find the thermodynamic factors controlling the compatibility, such as the temperature, concentration, molecular weight and the copolymer composition, etc. Topics investigated include: The polymer-polymer interaction parameter between polystyrene and polybutadiene was determined, and the applicability of mean field theories (Flory-Huggins theory and the equation-of-state theory) to the polymer miscibility was ascertained. The feasibility of determining the thickness of interfaces between dissimilar polymers by means of small-angle X-ray scattering was critically examined. The occurrence of the order-disorder transition in block copolymer system were investigated. Light scattering and small-angle X-ray scattering were utilized to study the phase transition and phase separation behavior of mixtures of a homopolymer and a block copolymer, and this led to the construction of phase diagrams which exhibit many new features not found with other types of polymer blends. Deuteration of polystyrene was found not to influence its miscibility with polybutadiene. The effectiveness of a random or block copolymer as a compatibilizer of homopolymer blends was investigated. The effect of molecular weight polydipersity on the cloud point curves of polymeric blends was investigated.

Author: Hamidi Abdul Aziz
Publisher: IJSR Publications
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 243

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Book Description
As the global population grows and many developing countries modernize, the importance of water supply and wastewater treatment becomes a much greater factor in the welfare of nations. Clearly, in today’s world the competition for water resources coupled with the unfortunate commingling of wastewater discharges with freshwater supplies creates additional pressure on treatment systems. Recently, researchers focus on wastewater treatment by difference methods with minimal cost and maximum efficiency. This volume of the Wastewater Engineering: Advanced Wastewater Treatment Systems is a selection of topics related to physical-chemical and biological processes with an emphasis on their industrial applications. It gives an overview of various aspects in wastewater treatments methods including topics such as biological, bioremediation, electrochemical, membrane and physical-chemical applications. Experts in the area of environmental sciences from diverse institutions worldwide have contributed to this book, which should prove to be useful to students, teachers, and researchers in the disciplines of wastewater engineering, chemical engineering, environmental engineering, and biotechnology. We gratefully acknowledge the cooperation and support of all the contributing authors.