Self-diffusion in bicontinuous cubic phases, L sub 3 phases, and microemulsions
- Univ. of Lund (Sweden)
The authors derive analytical and numerical results for the geometric obstruction factor in the case of self-diffusion within model cubic-phase microstructures and apply the results to the analysis of literature self-diffusion data in cubic phases, bicontinuous microemulsions, and L{sub 3} (or L*) phases. Each model microstructure is defined by a dividing surface, which divides the polar regions - surfactant head groups, and usually water - from the nonpolar regions - surfactant tails and possibly oil. The polar-apolar dividing surfaces treated are (1) interconnected cylinders, and (2) smooth surfaces of constant mean curvature, recently computed by one of the authors, which are generalizations of periodic minimal surfaces of identically zero mean curvature. The surfactant self-diffusion can often be modeled as diffusion of a particle confined to the polar-apolar dividing surface, with a constant diffusion coefficient D{sub 0}. Self-diffusion within the labyrinthine subvolumes created by each dividing surface is solved by a three-dimensional finite element calculation, yielding curves of {beta} = D{sub eff}/D{sub 0} (the obstruction factor) versus volume fraction.
- OSTI ID:
- 6067486
- Journal Information:
- Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:24; ISSN 0022-3654; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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