The effect of domain size polydispersity on the structural properties of lipid monolayers

ELENA RUFEIL FIORI

Trieste

Encuentro; Joint QLS-CMSP Virtual Summer Retreat on Heat, Water, Noise, and Life; 2020

INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS ; THE ABDUS SALAM

In lipid monolayers with phase coexistence, domains of the liquid-condensed phase always present size polydispersity. Because of the difference in surface densities, domains have excess dipolar density with respect to the surrounding liquid expanded phase, originating a dipolar inter-domain interaction. This interaction depends on the domain area, and hence the presence of a domain size distribution is associated with interaction polydispersity. By means of Brownian dynamics simulations, we study the radial distribution function (RDF) and the average time-dependent self-diffusion coefficient of lipid monolayers with normally distributed size domains. For this purpose, we vary the relevant system parameters, polydispersity and interaction strength, within a range of experimental interest. We also analyze the consequences of using a monodisperse model to determine the interaction strength from an experimental RDF.