Competitive adsorption of amphiphilic molecules and the stability of water-swollen micelles in oil.

Langmuir

Departments of Materials and Interfaces, Weizmann Institute of Science, PO Box 26, Rehovot 76100, Israel.

Published: August 2005

Motivated by recent attempts to confine biochemical processes inside water-in-oil microemulsions, we studied the composition and stability of mixed-amphiphile water-swollen micelles in oil from a theoretical point of view. A novel adsorption model demonstrates how the micellar contents (DNA, proteins, etc.) can dramatically affect the composition of the amphiphilic film and the resulting distribution of micelles. Special attention is given to the effect of electrostatic interactions within the micelles as well as between different ones. Since in a low dielectric medium charge fluctuations can lead to long-range intermicellar attractions, we suggest that the presence of amphiphilic polymers in the surfactant film may be needed to stabilize such microemulsions.

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http://dx.doi.org/10.1021/la0471036DOI Listing

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