Theoretical calculation of the phase behavior of colloidal membranes

TL;DR

This paper develops a density functional theory to predict phase behavior in colloidal membranes, identifying conditions for stability and aligning with experimental findings.

Contribution

It introduces a theoretical framework for understanding phase stability in colloidal membranes, emphasizing the role of aspect ratio and undulation effects.

Findings

Minimum rod aspect ratio needed for membrane stability

Protrusion undulations stabilize colloidal membranes

Qualitative agreement with experiments and simulations

Abstract

We formulate a density functional theory that describes the phase behavior of hard rods and depleting polymers, as realized in recent experiments on suspensions of \emph{fd} virus and non-adsorbing polymer. The theory predicts the relative stability of nematic droplets, stacked smectic columns, and a recently discovered phase of isolated monolayers of rods, or colloidal membranes. We find that a minimum rod aspect ratio is required for stability of colloidal membranes and that collective protrusion undulations are the dominant effect that stabilizes this phase. The theoretical predictions are shown to be qualitatively consistent with experimental and computational results.