Structure, dynamics and phase behavior of short rod inclusions dissolved in a colloidal membrane

TL;DR

This study investigates how short rod inclusions behave within colloidal membranes, revealing phase separation and complex structure formation driven by membrane-mediated interactions.

Contribution

It introduces a detailed analysis of short rod dynamics and phase behavior in colloidal membranes, highlighting new assembly mechanisms and interaction insights.

Findings

Short rods phase separate at higher concentrations.

Bilayer droplets enriched in short rods form within membranes.

Membrane-mediated interactions influence assembly processes.

Abstract

Inclusions dissolved in an anisotropic quasi-2D membrane acquire new types of interactions that can drive assembly of complex structures and patterns. We study colloidal membranes composed of a binary mixture of long and short rods, such that the length ratio of the long to short rods is approximately two. At very low volume fractions, short rods dissolve in the membrane of long rods by strongly anchoring to the membrane polymer interface. At higher fractions, the dissolved short rods phase separate from the background membrane, creating a composite structure comprised of bilayer droplets enriched in short rods that coexist with the background monolayer membrane. These results demonstrate that colloidal membranes serve as a versatile platform for assembly of soft materials, while simultaneously providing new insight into universal membrane-mediated interactions.