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Water-Insoluble Surface Coatings of Polyion−Surfactant Ion Complex Salts Respond to Additives in a Surrounding Aqueous Solution

Gustavsson, Charlotte LU ; Obiols-Rabasa, Marc LU and Piculell, Lennart LU (2015) In Langmuir 31(23). p.6487-6496
Abstract
Hydrated, but water-insoluble, “complex salts” (CS) composed of alkyltrimethylammonium surfactant ions with polyacrylate counterions are known to exhibit a rich phase behavior in bulk mixtures with water and have recently been shown to act as water-responsive surface coatings. Here it is shown, by SAXS measurements, that surface coatings of CS also respond to various added solutes in a surrounding aqueous solution, by altering their liquid crystalline structure. The obtained results provide new information on the phase behavior of CS in contact with water and aqueous solutions. Solutes such as acids, salts, excess ionic surfactant, or water-soluble polymers act on the CS by altering the polyion charge density, screening the electrostatic... (More)
Hydrated, but water-insoluble, “complex salts” (CS) composed of alkyltrimethylammonium surfactant ions with polyacrylate counterions are known to exhibit a rich phase behavior in bulk mixtures with water and have recently been shown to act as water-responsive surface coatings. Here it is shown, by SAXS measurements, that surface coatings of CS also respond to various added solutes in a surrounding aqueous solution, by altering their liquid crystalline structure. The obtained results provide new information on the phase behavior of CS in contact with water and aqueous solutions. Solutes such as acids, salts, excess ionic surfactant, or water-soluble polymers act on the CS by altering the polyion charge density, screening the electrostatic interaction, changing the curvature of the surfactant aggregate, or increasing the osmotic pressuring in the surrounding solution, all of which may result in a phase transition in the film. In water, all studied CS surface coatings had a micellar cubic structure, which could change to 2D hexagonal, HCP, or disordered micellar structure, depending on the identity of the CS and the identity and concentration of the added solute. For some systems, even dissolved CO2 from the ambient air was sufficient to induce a structural change in the film. Especially the films containing the long polyions remained intact even for large concentrations of solutes in the contacting solutions, and extensive washing in water resulted, in most cases, in films with the “original” structure found in water. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
31
issue
23
pages
6487 - 6496
publisher
The American Chemical Society
external identifiers
  • wos:000356755300025
  • scopus:84934945063
ISSN
0743-7463
DOI
10.1021/acs.langmuir.5b00831
language
English
LU publication?
yes
id
728ecbfc-e86e-40c4-b727-31bfd5ecff63 (old id 7439919)
date added to LUP
2015-06-24 16:24:24
date last changed
2017-10-01 03:28:39
@article{728ecbfc-e86e-40c4-b727-31bfd5ecff63,
  abstract     = {Hydrated, but water-insoluble, “complex salts” (CS) composed of alkyltrimethylammonium surfactant ions with polyacrylate counterions are known to exhibit a rich phase behavior in bulk mixtures with water and have recently been shown to act as water-responsive surface coatings. Here it is shown, by SAXS measurements, that surface coatings of CS also respond to various added solutes in a surrounding aqueous solution, by altering their liquid crystalline structure. The obtained results provide new information on the phase behavior of CS in contact with water and aqueous solutions. Solutes such as acids, salts, excess ionic surfactant, or water-soluble polymers act on the CS by altering the polyion charge density, screening the electrostatic interaction, changing the curvature of the surfactant aggregate, or increasing the osmotic pressuring in the surrounding solution, all of which may result in a phase transition in the film. In water, all studied CS surface coatings had a micellar cubic structure, which could change to 2D hexagonal, HCP, or disordered micellar structure, depending on the identity of the CS and the identity and concentration of the added solute. For some systems, even dissolved CO2 from the ambient air was sufficient to induce a structural change in the film. Especially the films containing the long polyions remained intact even for large concentrations of solutes in the contacting solutions, and extensive washing in water resulted, in most cases, in films with the “original” structure found in water.},
  author       = {Gustavsson, Charlotte and Obiols-Rabasa, Marc and Piculell, Lennart},
  issn         = {0743-7463},
  language     = {eng},
  number       = {23},
  pages        = {6487--6496},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Water-Insoluble Surface Coatings of Polyion−Surfactant Ion Complex Salts Respond to Additives in a Surrounding Aqueous Solution},
  url          = {http://dx.doi.org/10.1021/acs.langmuir.5b00831},
  volume       = {31},
  year         = {2015},
}