Effects of an amphiphilic graft copolymer on an oil-continuous microemulsion. Molecular self-diffusion and viscosity
(2002) In The Journal of Physical Chemistry Part B 106(10). p.2533-2544- Abstract
- Mixtures of an amphiphilic graft copolymer in water/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/cyclohexane oil-continuous microemulsions are studied by the PGSE NMR technique and by viscometry. The graft copolymer has an oil-soluble poly(dodecyl methacrylate) backbone and water-soluble poly(ethylene glycol) side chains. Water, surfactant, and polymer self-diffusion coefficients can be measured individually by PGSE NMR. The water and the surfactant self-diffusion coefficients are equal, and both monitor the overall diffusion of the water droplets of the microemulsion. The graft copolymer enhances the microemulsion viscosity (relative increase = 2000), and large viscosifying effects are promoted by increased degrees of grafting, increased... (More)
- Mixtures of an amphiphilic graft copolymer in water/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/cyclohexane oil-continuous microemulsions are studied by the PGSE NMR technique and by viscometry. The graft copolymer has an oil-soluble poly(dodecyl methacrylate) backbone and water-soluble poly(ethylene glycol) side chains. Water, surfactant, and polymer self-diffusion coefficients can be measured individually by PGSE NMR. The water and the surfactant self-diffusion coefficients are equal, and both monitor the overall diffusion of the water droplets of the microemulsion. The graft copolymer enhances the microemulsion viscosity (relative increase = 2000), and large viscosifying effects are promoted by increased degrees of grafting, increased polymer concentration, and large water droplets. Systems with high viscosities always display slow polymer self-diffusion. The droplet diffusion is always much more rapid than the polymer diffusion; thus, the polymer molecules do not immobilize the droplets. The results give the following microscopic picture of the mixtures. Polydisperse, but mostly finite, polymer-droplet aggregates coexist with a large fraction (30%) of "free" droplets. The aggregate size varies strongly with the polymer concentration, but only at the highest polymer concentration investigated (28 g/dm(3)) is there evidence of a fraction of very large (possibly infinite) aggregates. If the polymer/droplet ratio is increased, or if the mixture is diluted by oil, the system responds by inserting more polymer side chains per bound droplet, thus maintaining a high free-droplet concentration. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/342016
- author
- Holmberg, A ; Piculell, Lennart LU and Nyden, M
- organization
- publishing date
- 2002
- type
- Contribution to journal
- publication status
- published
- subject
- in
- The Journal of Physical Chemistry Part B
- volume
- 106
- issue
- 10
- pages
- 2533 - 2544
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000174369400017
- scopus:0037075814
- ISSN
- 1520-5207
- DOI
- 10.1021/jp0139235
- language
- English
- LU publication?
- yes
- id
- a33f5035-6c7d-4b5a-8e2a-fcbc4e23558f (old id 342016)
- date added to LUP
- 2016-04-01 15:52:14
- date last changed
- 2022-02-12 18:11:07
@article{a33f5035-6c7d-4b5a-8e2a-fcbc4e23558f,
abstract = {{Mixtures of an amphiphilic graft copolymer in water/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/cyclohexane oil-continuous microemulsions are studied by the PGSE NMR technique and by viscometry. The graft copolymer has an oil-soluble poly(dodecyl methacrylate) backbone and water-soluble poly(ethylene glycol) side chains. Water, surfactant, and polymer self-diffusion coefficients can be measured individually by PGSE NMR. The water and the surfactant self-diffusion coefficients are equal, and both monitor the overall diffusion of the water droplets of the microemulsion. The graft copolymer enhances the microemulsion viscosity (relative increase = 2000), and large viscosifying effects are promoted by increased degrees of grafting, increased polymer concentration, and large water droplets. Systems with high viscosities always display slow polymer self-diffusion. The droplet diffusion is always much more rapid than the polymer diffusion; thus, the polymer molecules do not immobilize the droplets. The results give the following microscopic picture of the mixtures. Polydisperse, but mostly finite, polymer-droplet aggregates coexist with a large fraction (30%) of "free" droplets. The aggregate size varies strongly with the polymer concentration, but only at the highest polymer concentration investigated (28 g/dm(3)) is there evidence of a fraction of very large (possibly infinite) aggregates. If the polymer/droplet ratio is increased, or if the mixture is diluted by oil, the system responds by inserting more polymer side chains per bound droplet, thus maintaining a high free-droplet concentration.}},
author = {{Holmberg, A and Piculell, Lennart and Nyden, M}},
issn = {{1520-5207}},
language = {{eng}},
number = {{10}},
pages = {{2533--2544}},
publisher = {{The American Chemical Society (ACS)}},
series = {{The Journal of Physical Chemistry Part B}},
title = {{Effects of an amphiphilic graft copolymer on an oil-continuous microemulsion. Molecular self-diffusion and viscosity}},
url = {{http://dx.doi.org/10.1021/jp0139235}},
doi = {{10.1021/jp0139235}},
volume = {{106}},
year = {{2002}},
}