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Polyelectrolytes on Surfaces and their Complexes with Surfactants, Thermodynamics versus kinetics

Samoshina, Yulia LU (2004)
Abstract
The interfacial properties of polyelectrolytes, mainly cationic with various content of amphiphilic groups, and their complexes with an oppositely charged surfactant, sodium dodecyl sulfate (SDS), have been investigated using time-resolved ellipsometry. This thesis focuses on the kinetics and reversibility aspects of polymer adsorption and the control of the adsorption by regulating the electrostatic interactions.



The formed structure of adsorbed layer was found to be dependent not only on the bulk conditions, but also on the pre-applied conditions, that is the path used to obtain a particular solution condition (e.g. by changing pH and concentration of salt, surfactant or polymer).



The results... (More)
The interfacial properties of polyelectrolytes, mainly cationic with various content of amphiphilic groups, and their complexes with an oppositely charged surfactant, sodium dodecyl sulfate (SDS), have been investigated using time-resolved ellipsometry. This thesis focuses on the kinetics and reversibility aspects of polymer adsorption and the control of the adsorption by regulating the electrostatic interactions.



The formed structure of adsorbed layer was found to be dependent not only on the bulk conditions, but also on the pre-applied conditions, that is the path used to obtain a particular solution condition (e.g. by changing pH and concentration of salt, surfactant or polymer).



The results indicate that polyelectrolyte adsorption appears only partially reversible, due to the high affinity to the surface, which slows down the rearrangement process. In general relaxation occurs more easily if the direction of the process is from low to the higher surface coverage.



By pre-applying certain bulk conditions, the desired conformation and enhanced (or reduced) concentration of the polymer in the interfacial layer can be achieved.



Association of the surfactant to the polymer seems to control the interfacial behavior, which depends on the surfactant concentration. In all cases, the maximum adsorption was obtained at a SDS concentration just before the expected phase separation region, while the complex in some cases could desorb from the surface at high SDS concentration (above the cmc).



Different results were obtained for coadsoption of amphiphilic polyelectrolytes when surfactant SDS was added to the preadsorbed layers and when complexes were preformed in the solution prior the adsorption. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Klitzing, Regine V, Kiel University, Germany
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Fysikalisk kemi, Polymer technology, Physical chemistry, SDS, amphiphilic polyelectrolytes, ellipsometry, reversibility, kinetics of adsorption, polyelectrolytes at solid-liquid interface, polyelectrolyte-oppositely charged surfactant complexes, biopolymers, Polymerteknik
pages
178 pages
publisher
Department of Physical Chemistry, Lund University
defense location
sal D, Chemical Center
defense date
2004-11-26 10:15
ISBN
91-7422-066-7
language
English
LU publication?
yes
id
7932bc29-9454-450c-90f2-1612a9e460cd (old id 467609)
date added to LUP
2007-10-13 15:07:44
date last changed
2016-09-19 08:45:13
@misc{7932bc29-9454-450c-90f2-1612a9e460cd,
  abstract     = {The interfacial properties of polyelectrolytes, mainly cationic with various content of amphiphilic groups, and their complexes with an oppositely charged surfactant, sodium dodecyl sulfate (SDS), have been investigated using time-resolved ellipsometry. This thesis focuses on the kinetics and reversibility aspects of polymer adsorption and the control of the adsorption by regulating the electrostatic interactions.<br/><br>
<br/><br>
The formed structure of adsorbed layer was found to be dependent not only on the bulk conditions, but also on the pre-applied conditions, that is the path used to obtain a particular solution condition (e.g. by changing pH and concentration of salt, surfactant or polymer).<br/><br>
<br/><br>
The results indicate that polyelectrolyte adsorption appears only partially reversible, due to the high affinity to the surface, which slows down the rearrangement process. In general relaxation occurs more easily if the direction of the process is from low to the higher surface coverage.<br/><br>
<br/><br>
By pre-applying certain bulk conditions, the desired conformation and enhanced (or reduced) concentration of the polymer in the interfacial layer can be achieved.<br/><br>
<br/><br>
Association of the surfactant to the polymer seems to control the interfacial behavior, which depends on the surfactant concentration. In all cases, the maximum adsorption was obtained at a SDS concentration just before the expected phase separation region, while the complex in some cases could desorb from the surface at high SDS concentration (above the cmc).<br/><br>
<br/><br>
Different results were obtained for coadsoption of amphiphilic polyelectrolytes when surfactant SDS was added to the preadsorbed layers and when complexes were preformed in the solution prior the adsorption.},
  author       = {Samoshina, Yulia},
  isbn         = {91-7422-066-7},
  keyword      = {Fysikalisk kemi,Polymer technology,Physical chemistry,SDS,amphiphilic polyelectrolytes,ellipsometry,reversibility,kinetics of adsorption,polyelectrolytes at solid-liquid interface,polyelectrolyte-oppositely charged surfactant complexes,biopolymers,Polymerteknik},
  language     = {eng},
  pages        = {178},
  publisher    = {ARRAY(0x9c50cb0)},
  title        = {Polyelectrolytes on Surfaces and their Complexes with Surfactants, Thermodynamics versus kinetics},
  year         = {2004},
}