Eur. Phys. J. E 3, 259-271
Adhesion-induced lateral phase separation in membranes
1 Department of Materials and Interfaces,
Weizmann Institute of Science,
Rehovot 76100, Israel
2 School of Physics and Astronomy,
Raymond and Beverly Sackler Faculty of Exact Sciences,
Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
Received 12 January 2000 and Received in final form 15 May 2000
Abstract
Adhesion between membranes is studied using a phenomenological model,
where the inter-membrane distance is coupled to the
concentration of sticker molecules on the membranes.
The model applies to both adhesion of two flexible membranes and
to adhesion of one flexible membrane onto a second membrane
supported on a solid substrate.
We mainly consider the case where the sticker molecules form bridges
and adhere directly to both membranes.
The calculated mean-field phase diagrams show an upward shift of the
transition temperature indicating that the lateral phase separation
in the membrane is enhanced due to the coupling effect.
Hence the possibility of adhesion-induced lateral phase separation
is predicted.
For a particular choice of the parameters, the model exhibits a
tricritical behavior.
We also discuss the non-monotonous shape of the inter-membrane
distance occurring when the lateral phase separation takes place.
The inter-membrane distance relaxes to the bulk values with two
symmetric overshoots.
Adhesion mediated by other types of stickers is also considered.
PACS
87.16.-b Subcellular structure and processes -
68.10.-m Fluid surfaces and fluid-fluid interfaces -
82.70.-y Disperse systems
Copyright EDP Sciences, Società Italiana di Fisica, Springer-Verlag
