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Oil-continuous microemulsions mixed with an amphiphilic graft copolymer or with the parent homopolymer - Polymer-droplet interactions as revealed by phase behavior

Holmberg, Anna ; Piculell, Lennart LU ; Schurtenberger, P and Olsson, Ulf LU (2004) In Colloids and Surfaces A: Physicochemical and Engineering Aspects 250(1-3). p.325-336
Abstract
Polymer-droplet interactions have been Studied in AOT/water/isooctane oil-continuous microemulsions mixed with an amphiphilic graft copolymer. or with the parent homopolymer (AOT = sodium bis(2-ethylhexyl) sulfosuccinate). The graft copolymer has an oil-soluble poly(dodecyl methacrylate) backbone and water-soluble poly(ethylene glycol) side chains. Pseudo-ternary polymer/droplet/isooctane phase diagrams have been established for both the parent homopolymer and the graft copolymer, and the two types of mixture display entirely different phase behavior. The homopolymer-droplet interaction is repulsive, and a segregative phase separation occurs at high droplet concentrations. By contrast, the graft copolymer droplet interaction is attractive:... (More)
Polymer-droplet interactions have been Studied in AOT/water/isooctane oil-continuous microemulsions mixed with an amphiphilic graft copolymer. or with the parent homopolymer (AOT = sodium bis(2-ethylhexyl) sulfosuccinate). The graft copolymer has an oil-soluble poly(dodecyl methacrylate) backbone and water-soluble poly(ethylene glycol) side chains. Pseudo-ternary polymer/droplet/isooctane phase diagrams have been established for both the parent homopolymer and the graft copolymer, and the two types of mixture display entirely different phase behavior. The homopolymer-droplet interaction is repulsive, and a segregative phase separation occurs at high droplet concentrations. By contrast, the graft copolymer droplet interaction is attractive: the polymer is insoluble in the pure oil, but dissolves in the microemulsion. A comparatively high concentration of droplets is required to solubilize even small amounts of polymer. Static and dynamic light scattering has been performed in order to obtain information on structure and dynamics in the two types Of mixture. For optically matched microemulsions, with a vanishing excess polarizability of the droplets, the polymer dominates the intensity of scattered light. The absolute intensity of scattered light increases as phase separation is approached owing to large-scale concentration fluctuations. Dynamic light scattering shows two populations of diffusion coefficients; one Population originates from "free" microemulsion droplets and the other from the polymer (for homopolymer Mixtures) or from polymer-droplet aggregates (for mixtures with the graft copolymer). The graft copolymer forms lame polymer-droplet aggregates with a broad size distribution, which coexist with a significant fraction of free droplets. (C) 2004 Elsevier B.V. All rights reserved. (Less)
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publishing date
type
Contribution to journal
publication status
published
subject
in
Colloids and Surfaces A: Physicochemical and Engineering Aspects
volume
250
issue
1-3
pages
325 - 336
publisher
Elsevier
external identifiers
  • wos:000226157000044
  • scopus:10044284515
ISSN
0927-7757
DOI
10.1016/j.colsurfa.2004.06.040
language
English
LU publication?
yes
id
1d7cca5c-0c54-43d3-a233-6a54dcebf5d9 (old id 154111)
date added to LUP
2016-04-01 15:48:42
date last changed
2022-01-28 07:16:50
@article{1d7cca5c-0c54-43d3-a233-6a54dcebf5d9,
  abstract     = {{Polymer-droplet interactions have been Studied in AOT/water/isooctane oil-continuous microemulsions mixed with an amphiphilic graft copolymer. or with the parent homopolymer (AOT = sodium bis(2-ethylhexyl) sulfosuccinate). The graft copolymer has an oil-soluble poly(dodecyl methacrylate) backbone and water-soluble poly(ethylene glycol) side chains. Pseudo-ternary polymer/droplet/isooctane phase diagrams have been established for both the parent homopolymer and the graft copolymer, and the two types of mixture display entirely different phase behavior. The homopolymer-droplet interaction is repulsive, and a segregative phase separation occurs at high droplet concentrations. By contrast, the graft copolymer droplet interaction is attractive: the polymer is insoluble in the pure oil, but dissolves in the microemulsion. A comparatively high concentration of droplets is required to solubilize even small amounts of polymer. Static and dynamic light scattering has been performed in order to obtain information on structure and dynamics in the two types Of mixture. For optically matched microemulsions, with a vanishing excess polarizability of the droplets, the polymer dominates the intensity of scattered light. The absolute intensity of scattered light increases as phase separation is approached owing to large-scale concentration fluctuations. Dynamic light scattering shows two populations of diffusion coefficients; one Population originates from "free" microemulsion droplets and the other from the polymer (for homopolymer Mixtures) or from polymer-droplet aggregates (for mixtures with the graft copolymer). The graft copolymer forms lame polymer-droplet aggregates with a broad size distribution, which coexist with a significant fraction of free droplets. (C) 2004 Elsevier B.V. All rights reserved.}},
  author       = {{Holmberg, Anna and Piculell, Lennart and Schurtenberger, P and Olsson, Ulf}},
  issn         = {{0927-7757}},
  language     = {{eng}},
  number       = {{1-3}},
  pages        = {{325--336}},
  publisher    = {{Elsevier}},
  series       = {{Colloids and Surfaces A: Physicochemical and Engineering Aspects}},
  title        = {{Oil-continuous microemulsions mixed with an amphiphilic graft copolymer or with the parent homopolymer - Polymer-droplet interactions as revealed by phase behavior}},
  url          = {{http://dx.doi.org/10.1016/j.colsurfa.2004.06.040}},
  doi          = {{10.1016/j.colsurfa.2004.06.040}},
  volume       = {{250}},
  year         = {{2004}},
}