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Structure and transport properties of a charged spherical microemulsion system

Evilevitch, Alex LU ; Lobaskin, V.; Linse, Per LU ; Olsson, Ulf LU and Schurtenberger, Peter (2001) In Langmuir 17(4). p.1043-1053
Abstract
Structure and transport properties of an oil-in-water microemulsion of weakly charged spherical micelles were studied experimentally using viscosity, NMR self-diffusion, and static and dynamic light scattering as well as theoretically by Brownian dynamics and Monte Carlo simulations and the Poisson-Boltzmann equation. The micelles contain decane covered by the nonionic surfactant pentaethylene glycol dodecyl ether (C12E5) and the ionic surfactant sodium dodecyl sulfate. The system has a constant surfactant-to-oil ratio, and the total volume fraction of surfactant and oil, , is varied between 0.01 0.46. The micelles were made weakly charged by replacing a small fraction (0.01, 0.04, and 0.06) of the nonionic surfactant with ionic... (More)
Structure and transport properties of an oil-in-water microemulsion of weakly charged spherical micelles were studied experimentally using viscosity, NMR self-diffusion, and static and dynamic light scattering as well as theoretically by Brownian dynamics and Monte Carlo simulations and the Poisson-Boltzmann equation. The micelles contain decane covered by the nonionic surfactant pentaethylene glycol dodecyl ether (C12E5) and the ionic surfactant sodium dodecyl sulfate. The system has a constant surfactant-to-oil ratio, and the total volume fraction of surfactant and oil, , is varied between 0.01 0.46. The micelles were made weakly charged by replacing a small fraction (0.01, 0.04, and 0.06) of the nonionic surfactant with ionic surfactant, retaining the micellar size. Comparison between self-diffusion and viscosity coefficients measured as a function of concentration showed that the system obeys the generalized Stokes-Einstein relation at lower micellar concentrations. At higher micellar concentrations, a slightly modified equation can be used upon the addition of an extra frictional factor due to stronger interactions. The collective diffusion coefficient shows a maximum as a function of the volume fraction. This result is in good agreement with predictions based on a charged hard-sphere model with hydrodynamic interactions. Other static and dynamic properties such as osmotic pressure, osmotic compressibility, and self-diffusion coefficient were obtained theoretically from simulations based on a charged-sphere model. The static and dynamic properties of the charged hard-sphere model qualitatively describe the behavior of the charged microemulsion micelles. At high volume fractions, > 0.1, the agreement is quantitative, but at < 0.1 the effect of the charge is smaller than what is predicted from the model. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
17
issue
4
pages
1043 - 1053
publisher
The American Chemical Society
external identifiers
  • scopus:0035249617
ISSN
0743-7463
DOI
10.1021/la0011883
language
English
LU publication?
yes
id
6a40c61b-f98d-4c51-9d16-5be663981f7a (old id 947791)
date added to LUP
2008-01-24 17:35:28
date last changed
2018-05-29 10:04:39
@article{6a40c61b-f98d-4c51-9d16-5be663981f7a,
  abstract     = {Structure and transport properties of an oil-in-water microemulsion of weakly charged spherical micelles were studied experimentally using viscosity, NMR self-diffusion, and static and dynamic light scattering as well as theoretically by Brownian dynamics and Monte Carlo simulations and the Poisson-Boltzmann equation. The micelles contain decane covered by the nonionic surfactant pentaethylene glycol dodecyl ether (C12E5) and the ionic surfactant sodium dodecyl sulfate. The system has a constant surfactant-to-oil ratio, and the total volume fraction of surfactant and oil, , is varied between 0.01 0.46. The micelles were made weakly charged by replacing a small fraction (0.01, 0.04, and 0.06) of the nonionic surfactant with ionic surfactant, retaining the micellar size. Comparison between self-diffusion and viscosity coefficients measured as a function of concentration showed that the system obeys the generalized Stokes-Einstein relation at lower micellar concentrations. At higher micellar concentrations, a slightly modified equation can be used upon the addition of an extra frictional factor due to stronger interactions. The collective diffusion coefficient shows a maximum as a function of the volume fraction. This result is in good agreement with predictions based on a charged hard-sphere model with hydrodynamic interactions. Other static and dynamic properties such as osmotic pressure, osmotic compressibility, and self-diffusion coefficient were obtained theoretically from simulations based on a charged-sphere model. The static and dynamic properties of the charged hard-sphere model qualitatively describe the behavior of the charged microemulsion micelles. At high volume fractions, &gt; 0.1, the agreement is quantitative, but at &lt; 0.1 the effect of the charge is smaller than what is predicted from the model.},
  author       = {Evilevitch, Alex and Lobaskin, V. and Linse, Per and Olsson, Ulf and Schurtenberger, Peter},
  issn         = {0743-7463},
  language     = {eng},
  number       = {4},
  pages        = {1043--1053},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Structure and transport properties of a charged spherical microemulsion system},
  url          = {http://dx.doi.org/10.1021/la0011883},
  volume       = {17},
  year         = {2001},
}