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Association of imidazolium surfactants with poly(N-isopropylacrylamide)

Usma, Cesar L.; Lindman, Björn LU ; Alfredsson, Viveka LU ; Taboada, Pablo; Renamayor, Carmen S. and Pacios, Isabel E. (2018) In Journal of Molecular Liquids 265. p.46-52
Abstract

Most investigations about polymer and surfactant interactions are related to standard surfactants, while the scope of literature using imidazolium surfactants is limited. In this work, conductometric and calorimetric techniques have been combined to determine the interaction of poly(N-isopropylacrylamide) with two surfactants: 1-tetradecyl-3-methylimidazolium chloride and 1-hexadecyl-3-methylimidazolium chloride. The critical aggregation concentration and the polymer saturation point have been determined as a function of the polymer concentration. To explain the conductivity results, a new model has been proposed that considers the possibility of formation of free micelles before the polymer saturation. This model allows estimating the... (More)

Most investigations about polymer and surfactant interactions are related to standard surfactants, while the scope of literature using imidazolium surfactants is limited. In this work, conductometric and calorimetric techniques have been combined to determine the interaction of poly(N-isopropylacrylamide) with two surfactants: 1-tetradecyl-3-methylimidazolium chloride and 1-hexadecyl-3-methylimidazolium chloride. The critical aggregation concentration and the polymer saturation point have been determined as a function of the polymer concentration. To explain the conductivity results, a new model has been proposed that considers the possibility of formation of free micelles before the polymer saturation. This model allows estimating the fraction of surfactant molecules aggregated to the polymer and the ionization degree of them, as well as the fraction of surfactant in the form of free micelles. Isothermal titration calorimetry results reveal that the interaction between the polymer and both surfactants is driven by entropic processes and that the aggregation process is non-cooperative at the initial stages.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Conductivity, Critical aggregation concentration, Isothermal titration calorimetry, Poly(N-isopropylacrylamide), Surfactant imidazolium derivatives
in
Journal of Molecular Liquids
volume
265
pages
7 pages
publisher
Elsevier
external identifiers
  • scopus:85047930421
ISSN
0167-7322
DOI
language
English
LU publication?
yes
id
cd8cc649-ceb8-4dc6-a98f-21507c57c66c
date added to LUP
2018-06-11 10:57:06
date last changed
2018-06-11 10:57:06
@article{cd8cc649-ceb8-4dc6-a98f-21507c57c66c,
  abstract     = {<p>Most investigations about polymer and surfactant interactions are related to standard surfactants, while the scope of literature using imidazolium surfactants is limited. In this work, conductometric and calorimetric techniques have been combined to determine the interaction of poly(N-isopropylacrylamide) with two surfactants: 1-tetradecyl-3-methylimidazolium chloride and 1-hexadecyl-3-methylimidazolium chloride. The critical aggregation concentration and the polymer saturation point have been determined as a function of the polymer concentration. To explain the conductivity results, a new model has been proposed that considers the possibility of formation of free micelles before the polymer saturation. This model allows estimating the fraction of surfactant molecules aggregated to the polymer and the ionization degree of them, as well as the fraction of surfactant in the form of free micelles. Isothermal titration calorimetry results reveal that the interaction between the polymer and both surfactants is driven by entropic processes and that the aggregation process is non-cooperative at the initial stages.</p>},
  author       = {Usma, Cesar L. and Lindman, Björn and Alfredsson, Viveka and Taboada, Pablo and Renamayor, Carmen S. and Pacios, Isabel E.},
  issn         = {0167-7322},
  keyword      = {Conductivity,Critical aggregation concentration,Isothermal titration calorimetry,Poly(N-isopropylacrylamide),Surfactant imidazolium derivatives},
  language     = {eng},
  month        = {09},
  pages        = {46--52},
  publisher    = {Elsevier},
  series       = {Journal of Molecular Liquids},
  title        = {Association of imidazolium surfactants with poly(N-isopropylacrylamide)},
  url          = {http://dx.doi.org/},
  volume       = {265},
  year         = {2018},
}