Author: Sidney Michael KilbeyPublisher:
ISBN:
Category :
Languages : en
Pages : 352
Book Description
Dynamic Behavior of Block Copolymers
Author: Sidney Michael KilbeyPublisher:
ISBN:
Category :
Languages : en
Pages : 352
Book Description
Block Copolymers
Author: Nikos HadjichristidisPublisher: John Wiley & Sons
ISBN: 0471461342
Category : Technology & Engineering
Languages : en
Pages : 445
Book Description
Polymers may be classified as either homopolymers, consisting of one single repeating unit, or copolymers, consisting of two or more distinct repeating units. Block copolymers contain long contiguous blocks of two or more repeating units in the same polymer chain. Covering one of the hottest topics in polymer chemistry, Block Copolymers provides a coherent overview of the synthetic routes, physical properties, and applications of block copolymers. This pioneering text provides not only a guideline for developing synthetic strategies for creating block copolymers with defined characteristics, but also a key to the relationship between the physical properties of block copolymers and the structure and dynamics of materials. Covering features of the chemistry and physics of block copolymers that are not found in comparable texts, Block Copolymers illustrates the structure-activity relationship of block copolymers and offers suggestions for the design of specific applications. Divided into five sections-Block Copolymers includes chapters on: * Block Copolymers by Chemical Modification of Precursor Polymers * Nonlinear Block Copolymers * Adsorption of Block Copolymers at Solid-Liquid Interfaces * Theory of Block Copolymer Segregation * Phase Transformation Kinetics * Block Copolymer Morphology * Block Copolymer Dynamics Polymer chemists, physicists, chemical engineers, and materials scientists, as well as graduate students in polymer science, will find Block Copolymers to be an invaluable text.
Structure and Dynamic Properties of Interfacially Modified Block Copolymers from Molecular Dynamics Simulations
Author: Youngmi SeoPublisher:
ISBN:
Category : Block copolymers
Languages : en
Pages : 135
Book Description
Nanostructured diblock copolymers, in which one can take advantage of the different properties of two types of monomers, are of interest in transport applications such as battery electrolytes. One can modify structural properties of diblock copolymers by inserting a midblock with a different composition between the two pure blocks. We study linearly tapered block polymers (TBPs) which are AB diblock copolymers modified by adding a linear gradient region (taper) between the blocks in which composition varies from one species to the other. This gives an additional tuning parameter, the length of the taper, to control the microphase separation behavior, e.g. increased accessibility of the bicontinuous double gyroid phase, or dynamic properties potentially of interest in transport applications. Here, we use molecular dynamics (MD) simulations to investigate both the structural and dynamic properties of TBPs and related block polymer systems. The MD results are consistent with the theoretical results in which the double gyroid network structure is more accessible with a taper and both the effective segregation strength and domain spacing decrease. Interestingly, the inverse TBPs, which have the B-side of the taper bonded to the pure A block, have a significantly shorter domain spacing compared to the normal TBPs. This is related to the polymer conformations; in contrast to typical diblocks or normal TBPs, inverse tapered chains can exist in several distinct conformations. For instance, inverse tapered chains may fold back and forth across the interface, bridge between multiple domains, or stretch over two layers of lamellae depending on the taper length. This conformational behavior was quantitatively analyzed as a function of the taper length. Theoretical work had predicted that the 50% inverse TBPs have a unique phase diagram; the larger of the two pure end blocks can phase separate into double gyroid phases. The MD results also show such a double gyroid structure for the 50% inverse TBPs. To understand the potential impact of tapers on ion dynamics, we investigated the diffusion of a small amount of penetrants in both normal and inverse TBPs. We considered uncharged monomer-sized penetrants, which have favorable interactions with A monomers of a strength that is chosen to make an analogy with the solvation of ions in the higher dielectric microphase of certain experimentally relevant copolymers. With normal tapering, both polymer and penetrant diffusion parallel to the lamellae increases as taper length increases, but inverse tapers show a non-monotonic variation in polymer diffusion. This is explained by analyzing differences in dynamic behavior between inverse tapered polymers with different types of conformations. However, regardless of the type of the midblocks, the penetrants’ diffusion constant values generally collapsed on a single curve when plotted against blockiness (average block length as a fraction of chain length) or number of A-B bonds per chain which can represent the degree of local A-B mixing. This implies that the local A-B mixing of monomers (rather than polymer conformation) is the most important factor in determining penetrant diffusion. These insights may allow improved design of nanostructured membranes for small molecule transport.
Block Copolymers
Author: Francisco Balta CallejaPublisher: CRC Press
ISBN: 9780824703820
Category : Technology & Engineering
Languages : en
Pages : 604
Book Description
A summary of block copolymer chemical structures and synthesis. It discusses physical methods of characterization such as computer simulation, microhardness, dielectric spectroscopy, thermal mechanical relaxation, ultrasonic characterization, transmission electron microscopy, X-ray scattering, and NMR, among others. It also outlines rheological and processing parameters in the multiphase polymer systems with stable microstructures.
Structures and Dynamics of Block Copolymer Melts and Solutions
Author: Chang Yeol RyuAmphiphilic Block Copolymers
Author: P. AlexandridisPublisher: Elsevier
ISBN: 0080527108
Category : Science
Languages : en
Pages : 449
Book Description
It is the belief of the editors of this book that the recognition of block copolymers as being amphiphilic molecules and sharing common features with other well-studied amphiphiles will prove beneficial to both the surfactant and the polymer communities. An aim of this book is to bridge the two communities and cross-fertilise the different fields. To this end, leading researchers in the field of amphiphilic block copolymer self-assembly, some having a background in surfactant chemistry, and others with polymer physics roots, have agreed to join forces and contribute to this book.The book consists of four entities. The first part discusses theoretical considerations behind the block copolymer self-assembly in solution and in the melt. The second part provides case studies of self-assembly in different classes of block copolymers (e.g., polyethers, polyelectrolytes) and in different environments (e.g., in water, in non-aqueous solvents, or in the absence of solvents). The third part presents experimental tools, ranging from static (e.g., small angle neutron scattering) to dynamic (e.g., rheology), which can prove valuable in the characterization of block copolymer self-assemblies. The fourth part offers a sampling of current applications of block copolymers in, e.g., formulations, pharmaceutics, and separations, applications which are based on the unique self-assembly properties of block copolymers.
Block Copolymers
Author: Ashish Kumar KhandpurPublisher:
ISBN:
Category :
Languages : en
Pages : 434
Book Description
Block Copolymers
Author: Kenneth J. HanleyEquilibrium and dynamic phase behavior in thin films of cylinder forming block copolymers
Author: Armin KnollProcessing, Structure and Properties of Block Copolymers
Author: M.J. FolkesPublisher: Springer Science & Business Media
ISBN: 9400949367
Category : Technology & Engineering
Languages : en
Pages : 219
Book Description
Block copolymers represent an important class of multi-phase material, which have received very widespread attention, particularly since their successful commercial development in the mid-1960s. Much of the interest in these polymers has arisen because of their rather remarkable micro phase morphology and, hence, they have been the subject of extensive microstructural examination. In many respects, the quest for a comprehensive interpretation of their structure, both theoretically and experimentally, has not been generally matched by a corresponding enthusiasm for developing structure/property relationships in the context of their commercial application. Indeed, it has been left largely to the industrial companies involved in the development and utilization of these materials to fulfil this latter role. While it is generally disappointing that a much greater synergism does not exist between science and technology, it is especially sad in the case of block copolymers. Thus these materials offer an almost unique opportunity for the application of fundamental structural and property data to the interpretation of the properties of generally processed artefacts. Accordingly, in this book, the editor has drawn together an eminent group of research workers, with the specific intention of highlighting some of those aspects of the science and technology of block copolymers that are potentially important if further advances are to be made either in material formulation or utilization. For example, special consideration is given to the relationship between the flow properties of block copo lymers and their microstructure.