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Phase Behavior of aqueous polyion-surfactant ion complex salts: Effects of polyion charge density

Norrman, Jens LU ; Lynch, Iseult and Piculell, Lennart LU (2007) In The Journal of Physical Chemistry Part B 111(29). p.8402-8410
Abstract
The effect of varying the fraction of charged monomer units of the polyion in aqueous polyion-oppositely charged surfactant complex salts has been investigated. The complex salts used were based on cetyltrimethylammonium (C(16)TA(+)) with three different polymeric counterions: poly(acrylate) (PA(-)) or poly(acrylate) copolymerized with either dimethylacrylamide (PA(-)/DAM) or N-isopropylamide (PA(-)/NIPAM). The charge density of the polyion was varied by either adding poly(acrylic) acid (PAA) to the C(16)TAPA complex salt (annealed charges) or by varying the fraction of uncharged units in the C(16)TAPA/DAM or C(16)TAPA/NIPAM complex salts (quenched charges). The formed phases were studied visually between crossed polarizers and by small... (More)
The effect of varying the fraction of charged monomer units of the polyion in aqueous polyion-oppositely charged surfactant complex salts has been investigated. The complex salts used were based on cetyltrimethylammonium (C(16)TA(+)) with three different polymeric counterions: poly(acrylate) (PA(-)) or poly(acrylate) copolymerized with either dimethylacrylamide (PA(-)/DAM) or N-isopropylamide (PA(-)/NIPAM). The charge density of the polyion was varied by either adding poly(acrylic) acid (PAA) to the C(16)TAPA complex salt (annealed charges) or by varying the fraction of uncharged units in the C(16)TAPA/DAM or C(16)TAPA/NIPAM complex salts (quenched charges). The formed phases were studied visually between crossed polarizers and by small angle X-ray scattering (SAXS). Both types of complex salts (annealed and quenched) formed hexagonal phases at high fractions of charged monomers and low water contents. Upon increasing the water content, a cubic phase of the Pm3n space group was found. Upon further addition of water, a miscibility gap with the cubic phase in equilibrium with pure water was found. Decreasing the fraction of charged monomers in the annealed complex salt resulted in an increase of the curvature of the surfactant aggregates. Only at very low (< 0.05) fractions of charged monomers did the packing of the surfactant aggregates lose long-range order, and eventually, the miscibility gap disappeared. For the quenched complex salts, the changes upon decreasing the fraction of charged monomers in the polyion were similar, but the loss of long-range order occurred at much higher fractions of charged monomers. The average surfactant aggregation number in the surfactant aggregates, which was similar for the annealed and quenched systems, decreased when the fraction of charged monomers was decreased. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part B
volume
111
issue
29
pages
8402 - 8410
publisher
The American Chemical Society
external identifiers
  • wos:000248121500011
  • scopus:34547661891
ISSN
1520-5207
DOI
10.1021/jp067303l
language
English
LU publication?
yes
id
72ab481d-5e8d-445b-8880-270a9fcdd28a (old id 646364)
date added to LUP
2007-12-14 10:56:02
date last changed
2017-10-01 04:52:54
@article{72ab481d-5e8d-445b-8880-270a9fcdd28a,
  abstract     = {The effect of varying the fraction of charged monomer units of the polyion in aqueous polyion-oppositely charged surfactant complex salts has been investigated. The complex salts used were based on cetyltrimethylammonium (C(16)TA(+)) with three different polymeric counterions: poly(acrylate) (PA(-)) or poly(acrylate) copolymerized with either dimethylacrylamide (PA(-)/DAM) or N-isopropylamide (PA(-)/NIPAM). The charge density of the polyion was varied by either adding poly(acrylic) acid (PAA) to the C(16)TAPA complex salt (annealed charges) or by varying the fraction of uncharged units in the C(16)TAPA/DAM or C(16)TAPA/NIPAM complex salts (quenched charges). The formed phases were studied visually between crossed polarizers and by small angle X-ray scattering (SAXS). Both types of complex salts (annealed and quenched) formed hexagonal phases at high fractions of charged monomers and low water contents. Upon increasing the water content, a cubic phase of the Pm3n space group was found. Upon further addition of water, a miscibility gap with the cubic phase in equilibrium with pure water was found. Decreasing the fraction of charged monomers in the annealed complex salt resulted in an increase of the curvature of the surfactant aggregates. Only at very low (&lt; 0.05) fractions of charged monomers did the packing of the surfactant aggregates lose long-range order, and eventually, the miscibility gap disappeared. For the quenched complex salts, the changes upon decreasing the fraction of charged monomers in the polyion were similar, but the loss of long-range order occurred at much higher fractions of charged monomers. The average surfactant aggregation number in the surfactant aggregates, which was similar for the annealed and quenched systems, decreased when the fraction of charged monomers was decreased.},
  author       = {Norrman, Jens and Lynch, Iseult and Piculell, Lennart},
  issn         = {1520-5207},
  language     = {eng},
  number       = {29},
  pages        = {8402--8410},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Phase Behavior of aqueous polyion-surfactant ion complex salts: Effects of polyion charge density},
  url          = {http://dx.doi.org/10.1021/jp067303l},
  volume       = {111},
  year         = {2007},
}