Author: Kehua Lin Publisher: ISBN: Category : Materials science Languages : en Pages : 94
Book Description
Polyelectrolyte and microgel were used as a model to investigate the structure and dynamics of complex liquid. In chapter 2, a coacervate system that is associated with net neutral polybetaine and cationic P2VP was applied in this research work as an environment for polyelectrolyte whose confirmation is characterized by fluorescence correlation spectroscopy. Surprisingly, the chain confirmation of the positive charged polyelectrolyte, P2VP, behaves oppositely compared to that in dilute solution. With the increased pH, the chain remains swollen upon coacervation or even slightly more expanded while the chain would collapse due to the low charge density at high pH. Schematic illustration of f-P2VP and the phase behavior is further investigated. In chapter 3 and 4, the spatial confinement of the microgel system suspension at near supercool region and supercool region under different confinement wall was investigated under confocal microscope and the dynamics was further extracted by image analysis. We found the softer wall can weaken the confinement effect and result in a higher mobility, even for the hard microgel suspension. The onsite height of confinement effect is increase with decreased stiffness of the wall. The mobile cluster which treated as dynamics structure and the pair correlation function under different surface confinement was further investigated. The size of mobile cluster decreased and a more disorder structure is observed when stiffness of the confinement wall reduced.
Author: Redouane Borsali Publisher: Springer Science & Business Media ISBN: 9401004420 Category : Science Languages : en Pages : 478
Book Description
This volume is based on lectures given at the NATO-Advanced Study Institute on Structure and Dynamics of Polymer and Colloid Systems held in Les Houches, France from September 14-24, 1999. The meeting arose from a perceived need to bring together scientists studying the polymer and colloid fields. Although these fields are intertwined and share many techniques (e. g. , light, neutron and x-ray scattering), it is remarkable how little the approaches and concepts used by the one field penetrate the other. For instance, the theory of spherical colloids is very highly developed and many of the concepts developed for these systems can be extended to those with non-spherical morphology, such as solutions of rigid rod polymers. In addition, mixtures of polymers and colloids, both in the bulk and at interfaces, are the basis for many industrial products. Methods are now rapidly being developed for understanding the structure and dynamics in polymer/colloid mixtures at the molecular level, but the point of view of the colloid scientist is often rather different from that of the polymer scientist. The NATO-ASI brought together polymer and colloid scientists, including many young researchers, who presented and discussed recent developments in these fields and the possibilities for cross-fertilization This volume contains articles on a wide variety of topics at the research forefront of the polymer and colloid fields by some of the world's foremost experts at a level accessible to graduate students, post-docs and researchers.
Author: Hamidreza Shojaei-Mahib Publisher: ISBN: Category : Languages : en Pages :
Book Description
Interaction of charged macromolecules among themselves and with charged interfaces in salty aqueous medium is a common phenomenon prevalent in biology and synthetic systems. We have addressed several inter-related issues in this general context. First we present a theory of adsorption of polyelectrolytes on the interior and exterior surfaces of a charged spherical vesicle. We derive the critical adsorption condition and the density profile of the polymer in terms of various characteristics of the polymer, vesicle, and the solution, such as the length and charge density of polymer, the radius and charge of the vesicle, the salt concentration of the solution, and the dielectric constant of the solvent. We have used the Wentzel-Kramers-Brillouin (WKB) method to solve the equation for the probability distribution function of the chain. For the polyelectrolyte inside the vesicle, the competition between the loss of conformational entropy and the attractive electrostatic energy between the vesicle and the polyelectrolyte, results in two different encapsulated states. By considering the adsorption from outside, we calculate the entropic and the energetic contributions to the free energy for the polymer being adsorbed in the interior and exterior states and the free energy penalty for the polyelectrolyte being expelled from the vesicle. The kinetics of the polyelectrolyte complexation have been studied using the Smoluchowski equation. We derive the mean distance between two oppositely charged polyelectrolytes and the reaction rate for the complexation in terms of the salt concentration and polyelectrolyte characteristics. We also calculate the half-time for the complexation process at different salt concentrations and initial distances.\\ For a vesicle, we have derived the free energy landscape of translocation through the pore by accounting for the energy penalty of bending and stretching the vesicle from due to deformation by pore. Using the Fokker-Planck formalism, we have calculated the average translocation time corresponding to the various free energy landscapes representing different parameter sets. We also discuss the dependencies of the average translocation time on the strength of the external force, vesicle size, bending and stretching moduli of the vesicle, and the radius and length of the pore. Finally, we formulate a theory of the effects of long-range interactions on surface tension and spontaneous curvature of proteinaceous shells based on the general Deryaguin-Landau-Verwey-Overbeek (DLVO) theory. we have derived the renormalized spontaneous curvature as a function of capsid's inner and outer charge density and solution properties.
Author: Visakh P. M. Publisher: Springer ISBN: 3319016806 Category : Technology & Engineering Languages : en Pages : 388
Book Description
This book offers a valuable reference source to graduate and post graduate students, engineering students, research scholars polymer engineers from industry. The book provides the reader with current developments of theoretical models describing the thermodynamics polyelectrolytes as well as experimental findings. A particular emphasis is put on the rheological description of polyelectrolyte solutions and hydrogels.
Author: Alberto Fernandez-Nieves Publisher: John Wiley & Sons ISBN: 3527633014 Category : Science Languages : en Pages : 475
Book Description
Providing a vital link between chemistry and physics on the nanoscale, this book offers concise coverage of the entire topic in five major sections, beginning with synthesis of microgel particles and continuing with their physical properties. The phase behavior and dynamics of resulting microgel suspensions feature in the third section, followed by their mechanical properties. It concludes with detailed accounts of numerous industrial, commercial and medical applications. Edited by David Weitz, Professor at Harvard and one of the world's pre-eminent experts in the field.
Author: Tsetska Radeva Publisher: CRC Press ISBN: 9780824704636 Category : Science Languages : en Pages : 910
Book Description
An examination of the fundamental nature of polyelectrolytes, static and dynamic properties of salt-free and salt-added solutions, and interactions with other charged and neutral species at interfaces with applications to industry and medicine. It applies the Metropolis Monte Carlo simulation to calculate counterion distributions, electric potentials, and fluctuation of counterion polarization for model DNA fragments.
Author: Kehua Lin
Author: Redouane Borsali
Author: Hamidreza Shojaei-Mahib
Author: Visakh P. M.
Author: Alberto Fernandez-Nieves
Author: Per Johan Råsmark
Author: Tsetska Radeva
Author: Amit Sehgal
Author: Aristeidis Papagiannopoulos
Author: Shih Ping Chen