Advanced

Theoretical and Experimental Studies of Polymer Adsorption and Polymer Mediated Interactions

Xie, Fei LU (2016)
Abstract
Polyelectrolyte adsorption and polymer mediated interactions in different colloidal polymer systems have been studied in this work. Theoretical methods and experimental techniques are combined, in order to obtain more general reliable results, as well as a deep understanding of the molecular mechanisms that are responsible for the observed behaviors. Two different types of highly charged cationic polyions have been used to explore the adsorption onto oppositely charged surfaces. The adsorption varies with concentration of simple salt and the adsorption dependence on molecular weight have been considered. Polymer density functional theory and null ellipsometry have been utilized to study the adsorption. Various colloidal polymer systems... (More)
Polyelectrolyte adsorption and polymer mediated interactions in different colloidal polymer systems have been studied in this work. Theoretical methods and experimental techniques are combined, in order to obtain more general reliable results, as well as a deep understanding of the molecular mechanisms that are responsible for the observed behaviors. Two different types of highly charged cationic polyions have been used to explore the adsorption onto oppositely charged surfaces. The adsorption varies with concentration of simple salt and the adsorption dependence on molecular weight have been considered. Polymer density functional theory and null ellipsometry have been utilized to study the adsorption. Various colloidal polymer systems have also been investigated in order to scrutinize polymer mediated interactions. For systems containing charged colloidal particles and non-adsorbing polyethylene oxide (PEO) chains, we studied gelation and constructed a coarse-grained model, to quantitatively compare predicted structure factors with corresponding experimental data. We have devoted some extra efforts to predict and understand the temperature response of polymer mediated interactions, in systems where the pure polymer solution display an local critical solution temperature (LCST). This has, for instance, resulted in predictions that such colloidal particle + polymer dispersions can display a phase behavior that responds on a nonmonotonic manner to temperature change (specifically: flocculated - dispersed - flocculated). these predictions are in qualitative agreement with experiments, and achieved without any assumptions of temperature-dependent
interactions. Another prediction from our studies on LCST polymer solutions, is that these may undergo phase separations in porous environments, even though there is only one phase for all compositions in the bulk solution. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Leermakers, Frans, Wageningen University, the Netherlands
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Polyelectrolyte , Adsorption, Colloid, Polymer, Dispersion, Interation, Ellipsometry, Monte Carlo Simulation, Classical Density Functional Theory
pages
180 pages
defense location
Hörsal B, Kemicentrum, Naturvetarvägen 14, Lund
defense date
2016-04-22 10:30
ISBN
978-91-7422-434-4
language
English
LU publication?
yes
id
a8f932fb-d483-4ba6-930c-b559fe6c3eff (old id 8871145)
date added to LUP
2016-04-17 20:12:58
date last changed
2017-01-13 15:53:27
@phdthesis{a8f932fb-d483-4ba6-930c-b559fe6c3eff,
  abstract     = {Polyelectrolyte adsorption and polymer mediated interactions in different colloidal polymer systems have been studied in this work. Theoretical methods and experimental techniques are combined, in order to obtain more general reliable results, as well as a deep understanding of the molecular mechanisms that are responsible for the observed behaviors. Two different types of highly charged cationic polyions have been used to explore the adsorption onto oppositely charged surfaces. The adsorption varies with concentration of simple salt and the adsorption dependence on molecular weight have been considered. Polymer density functional theory and null ellipsometry have been utilized to study the adsorption. Various colloidal polymer systems have also been investigated in order to scrutinize polymer mediated interactions. For systems containing charged colloidal particles and non-adsorbing polyethylene oxide (PEO) chains, we studied gelation and constructed a coarse-grained model, to quantitatively compare predicted structure factors with corresponding experimental data. We have devoted some extra efforts to predict and understand the temperature response of polymer mediated interactions, in systems where the pure polymer solution display an local critical solution temperature (LCST). This has, for instance, resulted in predictions that such colloidal particle + polymer dispersions can display a phase behavior that responds on a nonmonotonic manner to temperature change (specifically: flocculated - dispersed - flocculated). these predictions are in qualitative agreement with experiments, and achieved without any assumptions of temperature-dependent<br/>interactions. Another prediction from our studies on LCST polymer solutions, is that these may undergo phase separations in porous environments, even though there is only one phase for all compositions in the bulk solution.},
  author       = {Xie, Fei},
  isbn         = {978-91-7422-434-4},
  keyword      = {Polyelectrolyte ,Adsorption,Colloid,Polymer,Dispersion,Interation,Ellipsometry,Monte Carlo Simulation,Classical Density Functional Theory},
  language     = {eng},
  month        = {12},
  pages        = {180},
  school       = {Lund University},
  title        = {Theoretical and Experimental Studies of Polymer Adsorption and Polymer Mediated Interactions},
  year         = {2016},
}