Depletion Interactions in Model Microemulsions
(2004) In Langmuir 20(8). p.3080-3089- Abstract
- The effects of temperature changes and polymer addition on the behavior of droplet microemulsions of
nonionic surfactant, water, and decane are reported and analyzed within polymer depletion theory. Dilution
viscometry and dynamic light scattering were used to confirm that these microemulsions behave essentially
as hard-sphere dispersions, providing us with an ideal reference system. Addition of poly(ethylene glycol)
(PEG) lowers the emulsification failure boundary, where excess oil is expelled, which can be qualitatively
understood by an analysis of the available volume for the polymer. Sufficient addition of PEG causes a
fluid-fluid phase separation in qualitative accord with... (More) - The effects of temperature changes and polymer addition on the behavior of droplet microemulsions of
nonionic surfactant, water, and decane are reported and analyzed within polymer depletion theory. Dilution
viscometry and dynamic light scattering were used to confirm that these microemulsions behave essentially
as hard-sphere dispersions, providing us with an ideal reference system. Addition of poly(ethylene glycol)
(PEG) lowers the emulsification failure boundary, where excess oil is expelled, which can be qualitatively
understood by an analysis of the available volume for the polymer. Sufficient addition of PEG causes a
fluid-fluid phase separation in qualitative accord with experiments on mixtures of rigid colloidal hard
spheres and nonadsorbing polymer. Addition of PEG or raising the temperature causes the collective
diffusion coefficient DC to decrease. From theory, the initial linear slope of DC versus droplet concentration
can be used to discriminate between attractions and repulsions. The measured DC data for the droplets
in the presence of PEG are modeled using the Asakura-Oosawa theory of depletion. Fitting the theory
to the measured DC data permits for extracting the only unknown parameter, the polymer radius of
gyration. Quantitative agreement is found with literature data, demonstrating that polymer depletion
occurs in the system and that the Asakura-Oosawatheory provides a faithful description of the phenomenon. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3363698
- author
- Zackrisson Oskolkova, Malin LU ; Andersson, Robert and Bergenholtz, Johan
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- depletion interactions, microemulsions, hard sphere interactions, collective diffusion
- in
- Langmuir
- volume
- 20
- issue
- 8
- pages
- 3080 - 3089
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:2342432787
- ISSN
- 0743-7463
- DOI
- 10.1021/la036132y
- language
- English
- LU publication?
- no
- id
- 21065006-d95d-4d10-aa8a-18716136ac7c (old id 3363698)
- date added to LUP
- 2016-04-01 12:02:30
- date last changed
- 2022-01-26 21:56:18
@article{21065006-d95d-4d10-aa8a-18716136ac7c,
abstract = {{The effects of temperature changes and polymer addition on the behavior of droplet microemulsions of<br/><br>
nonionic surfactant, water, and decane are reported and analyzed within polymer depletion theory. Dilution<br/><br>
viscometry and dynamic light scattering were used to confirm that these microemulsions behave essentially<br/><br>
as hard-sphere dispersions, providing us with an ideal reference system. Addition of poly(ethylene glycol)<br/><br>
(PEG) lowers the emulsification failure boundary, where excess oil is expelled, which can be qualitatively<br/><br>
understood by an analysis of the available volume for the polymer. Sufficient addition of PEG causes a<br/><br>
fluid-fluid phase separation in qualitative accord with experiments on mixtures of rigid colloidal hard<br/><br>
spheres and nonadsorbing polymer. Addition of PEG or raising the temperature causes the collective<br/><br>
diffusion coefficient DC to decrease. From theory, the initial linear slope of DC versus droplet concentration<br/><br>
can be used to discriminate between attractions and repulsions. The measured DC data for the droplets<br/><br>
in the presence of PEG are modeled using the Asakura-Oosawa theory of depletion. Fitting the theory<br/><br>
to the measured DC data permits for extracting the only unknown parameter, the polymer radius of<br/><br>
gyration. Quantitative agreement is found with literature data, demonstrating that polymer depletion<br/><br>
occurs in the system and that the Asakura-Oosawatheory provides a faithful description of the phenomenon.}},
author = {{Zackrisson Oskolkova, Malin and Andersson, Robert and Bergenholtz, Johan}},
issn = {{0743-7463}},
keywords = {{depletion interactions; microemulsions; hard sphere interactions; collective diffusion}},
language = {{eng}},
number = {{8}},
pages = {{3080--3089}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Langmuir}},
title = {{Depletion Interactions in Model Microemulsions}},
url = {{http://dx.doi.org/10.1021/la036132y}},
doi = {{10.1021/la036132y}},
volume = {{20}},
year = {{2004}},
}