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Association Phenomena in Aqueous Solutions of Surfactants and Hydrophobically Modified Polymers

Nilsson, Susanne LU (1999)
Abstract
Interactions between ionic surfactants (sodium dodecyl sulfate and dodecyltrimethylammonium chloride) and nonionic polymers ((hydroxyethyl)cellulose, ethyl(hydroxyethyl)cellulose and their hydrophobically modified analogous) have been studied by means of rheology, pulsed field gradient nuclear magnetic resonance (PFG NMR), time-resolved fluorescence quenching (TRFQ), dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM). In all experiments surfactants have been added in various amounts to polymer solutions at fixed concentrations. The concentration of mixed micelles formed by surfactant molecules and hydrophobic tails of the polymer, binding isotherms, aggregation numbers and polymer self-diffusion... (More)
Interactions between ionic surfactants (sodium dodecyl sulfate and dodecyltrimethylammonium chloride) and nonionic polymers ((hydroxyethyl)cellulose, ethyl(hydroxyethyl)cellulose and their hydrophobically modified analogous) have been studied by means of rheology, pulsed field gradient nuclear magnetic resonance (PFG NMR), time-resolved fluorescence quenching (TRFQ), dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM). In all experiments surfactants have been added in various amounts to polymer solutions at fixed concentrations. The concentration of mixed micelles formed by surfactant molecules and hydrophobic tails of the polymer, binding isotherms, aggregation numbers and polymer self-diffusion coefficients have been obtained and correlated to viscosity. The viscosity increases where the number of mixed micelles is nearly unchanged but their aggregation number increases due to added surfactant, resulting in slower rheological and dynamic relaxation processes. The viscosity decrease occurs when the mixed micelles are dominated by surfactant molecules. Here, there is a strong increase in the number of mixed micelles and the number of hydrophobic tails per mixed micelle decreases. Under these circumstances when there are few polymer hydrophobic tails per mixed micelle, a high viscosity can be regained if the aggregation number increases, resulting in more polymer hydrophobic tails per mixed micelle. The aggregation number can be increased, by adding an oppositely charged surfactant or a screening electrolyte. The polymer-surfactant network undergo structural rearrangements from a heterogeneous structure at low surfactant concentration to a homogeneous structure at high levels of surfactant addition. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • van Stam, Jan, Docent, Physical Chemistry, Karlstad University, 651 88 Karlstad, Sweden
organization
publishing date
type
Thesis
publication status
published
subject
keywords
self-diffusion, rheology, cellulose ethers, associating polymers, polymer-surfactant interactions, polymer network, Fysikalisk kemi, Physical chemistry
pages
162 pages
publisher
Physical Chemistry 1, Lund University
defense location
N/A
defense date
1999-11-12 10:15
external identifiers
  • Other:ISRN: LUNKDL/NFK--99/1050--SE
ISBN
91-628-3818-0
language
English
LU publication?
yes
id
df31a372-936f-492f-947b-45aa09b65737 (old id 39973)
date added to LUP
2007-08-02 08:39:53
date last changed
2016-09-19 08:45:01
@misc{df31a372-936f-492f-947b-45aa09b65737,
  abstract     = {Interactions between ionic surfactants (sodium dodecyl sulfate and dodecyltrimethylammonium chloride) and nonionic polymers ((hydroxyethyl)cellulose, ethyl(hydroxyethyl)cellulose and their hydrophobically modified analogous) have been studied by means of rheology, pulsed field gradient nuclear magnetic resonance (PFG NMR), time-resolved fluorescence quenching (TRFQ), dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM). In all experiments surfactants have been added in various amounts to polymer solutions at fixed concentrations. The concentration of mixed micelles formed by surfactant molecules and hydrophobic tails of the polymer, binding isotherms, aggregation numbers and polymer self-diffusion coefficients have been obtained and correlated to viscosity. The viscosity increases where the number of mixed micelles is nearly unchanged but their aggregation number increases due to added surfactant, resulting in slower rheological and dynamic relaxation processes. The viscosity decrease occurs when the mixed micelles are dominated by surfactant molecules. Here, there is a strong increase in the number of mixed micelles and the number of hydrophobic tails per mixed micelle decreases. Under these circumstances when there are few polymer hydrophobic tails per mixed micelle, a high viscosity can be regained if the aggregation number increases, resulting in more polymer hydrophobic tails per mixed micelle. The aggregation number can be increased, by adding an oppositely charged surfactant or a screening electrolyte. The polymer-surfactant network undergo structural rearrangements from a heterogeneous structure at low surfactant concentration to a homogeneous structure at high levels of surfactant addition.},
  author       = {Nilsson, Susanne},
  isbn         = {91-628-3818-0},
  keyword      = {self-diffusion,rheology,cellulose ethers,associating polymers,polymer-surfactant interactions,polymer network,Fysikalisk kemi,Physical chemistry},
  language     = {eng},
  pages        = {162},
  publisher    = {ARRAY(0x8e729c8)},
  title        = {Association Phenomena in Aqueous Solutions of Surfactants and Hydrophobically Modified Polymers},
  year         = {1999},
}