Growth kinetics of circular liquid domains on vesicles by diffusion-controlled coalescence

TL;DR

This paper develops a theoretical model for the growth kinetics of liquid domains on vesicles, incorporating spherical geometry and diffusion-controlled coalescence, to better understand experimental observations in multi-component membranes.

Contribution

It introduces an analytical framework that accounts for vesicle shape and domain size dependence in domain coalescence growth kinetics, advancing prior flat membrane models.

Findings

Derived an analytical expression for domain growth kinetics on vesicles.

Demonstrated the importance of spherical geometry in steady-state coalescence rates.

Analyzed size dependence of diffusion coefficients for large domains.

Abstract

Motivated by recent experiments on multi-component membranes, the growth kinetics of domains on vesicles is theoretically studied. It is known that the steady-state rate of coalescence cannot be obtained by taking the long-time limit of the coalescence rate when the membrane is regarded as an infinite two-dimensional (2D) system. The steady-state rate of coalescence is obtained by explicitly taking into account the spherical vesicle shape. Using the expression of the 2D diffusion coefficient obtained in the limit of small domain size, an analytical expression for the domain growth kinetics is obtained when the circular shape is always maintained. For large domains, the growth kinetics is discussed by investigating the size dependence of the coalescence rate using the expression for the diffusion coefficient of arbitrary domain size.