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Fluctuation induced interactions between domains in membranes

D. S. Dean·M. Manghi
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Abstract

We study a model lipid bilayer composed of a mixture of two incompatible lipid types which have a natural tendency to segregate in the absence of membrane fluctuations. The membrane is mechanically characterized by a local bending rigidity $κ(ϕ)$ which varies with the average local lipid composition $ϕ$. We show, in the case where $κ$ varies weakly with $ϕ$, that the effective interaction between lipids of the same type can either be everywhere attractive or can have a repulsive component at intermediate distances greater than the typical lipid size. When this interaction has a repulsive component, it can prevent macro-phase separation and lead to separation in mesophases with a finite domain size. This effect could be relevant to certain experimental and numerical observations of mesoscopic domains in such systems.

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D. S. Dean, M. Manghi. 2006-09-06. Fluctuation induced interactions between domains in membranes. https://doi.org/10.1103/physreve.74.021916

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