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Particle-induced phase separation in mixed polymer solutions

Olsson, Martin LU ; Joabsson, Fredrik and Piculell, Lennart LU (2005) In Langmuir 21(4). p.1560-1567
Abstract
The influence of added colloidal particles on the phase separation of mixed aqueous polymer solutions is investigated. Two types of particles (polystyrene latex or silica) and different combinations of segregating polymers (dextran of varying molar mass combined with poly(ethylene oxide) (PEO) of varying molar mass, or Ucon, a copolymer of ethylene oxide and propylene oxide) were used. All systems displayed particle-induced instability effects, but the extent of the effect varied strongly between the various combinations and with the amount of added salt. Very large instability effects were seen in certain mixtures. Two mechanisms, both relying on the adsorption of at least one of the polymers to the particle surface, seem to operate.... (More)
The influence of added colloidal particles on the phase separation of mixed aqueous polymer solutions is investigated. Two types of particles (polystyrene latex or silica) and different combinations of segregating polymers (dextran of varying molar mass combined with poly(ethylene oxide) (PEO) of varying molar mass, or Ucon, a copolymer of ethylene oxide and propylene oxide) were used. All systems displayed particle-induced instability effects, but the extent of the effect varied strongly between the various combinations and with the amount of added salt. Very large instability effects were seen in certain mixtures. Two mechanisms, both relying on the adsorption of at least one of the polymers to the particle surface, seem to operate. Close to the cloud-point curve of the particle-free polymer 1/polymer2/water mixture, adsorption of PEO or Ucon to the particles gives rise to a capillary-induced phase separation. Close to the dextran/water axis of the phase diagram, the adsorbing polymer gives rise to a surface modification of the particles, which then interacts repulsively with the surrounding dextran solution. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
21
issue
4
pages
1560 - 1567
publisher
The American Chemical Society
external identifiers
  • wos:000226962100060
  • pmid:15697308
  • scopus:14144255502
ISSN
0743-7463
DOI
10.1021/la047762i
language
English
LU publication?
yes
id
09412994-7be9-4fab-af4c-9bf050c57b3c (old id 157521)
date added to LUP
2007-07-12 09:10:19
date last changed
2017-10-01 03:40:15
@article{09412994-7be9-4fab-af4c-9bf050c57b3c,
  abstract     = {The influence of added colloidal particles on the phase separation of mixed aqueous polymer solutions is investigated. Two types of particles (polystyrene latex or silica) and different combinations of segregating polymers (dextran of varying molar mass combined with poly(ethylene oxide) (PEO) of varying molar mass, or Ucon, a copolymer of ethylene oxide and propylene oxide) were used. All systems displayed particle-induced instability effects, but the extent of the effect varied strongly between the various combinations and with the amount of added salt. Very large instability effects were seen in certain mixtures. Two mechanisms, both relying on the adsorption of at least one of the polymers to the particle surface, seem to operate. Close to the cloud-point curve of the particle-free polymer 1/polymer2/water mixture, adsorption of PEO or Ucon to the particles gives rise to a capillary-induced phase separation. Close to the dextran/water axis of the phase diagram, the adsorbing polymer gives rise to a surface modification of the particles, which then interacts repulsively with the surrounding dextran solution.},
  author       = {Olsson, Martin and Joabsson, Fredrik and Piculell, Lennart},
  issn         = {0743-7463},
  language     = {eng},
  number       = {4},
  pages        = {1560--1567},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Particle-induced phase separation in mixed polymer solutions},
  url          = {http://dx.doi.org/10.1021/la047762i},
  volume       = {21},
  year         = {2005},
}