Smectic Polymer Vesicles

TL;DR

This paper reports the creation of glassy smectic polymer vesicles with ordered stripe patterns, topological defects, and potential for functionalization, advancing the understanding of matter organization on curved surfaces.

Contribution

It introduces a new type of smectic polymer vesicle with liquid crystalline properties and describes their structure, defects, and potential for functionalization.

Findings

Vesicles exhibit two-dimensional smectic order.

Vesicles are ellipsoidal with defects at the poles.

Potential for vesicle budding at defect sites.

Abstract

Polymer vesicles are stable robust vesicles made from block copolymer amphiphiles. Recent progress in the chemical design of block copolymers opens up the exciting possibility of creating a wide variety of polymer vesicles with varying fine structure, functionality and geometry. Polymer vesicles not only constitute useful systems for drug delivery and micro/nano-reactors but also provide an invaluable arena for exploring the ordering of matter on curved surfaces embedded in three dimensions. By choosing suitable liquid-crystalline polymers for one of the copolymer components one can create vesicles with smectic stripes. Smectic order on shapes of spherical topology inevitably possesses topological defects (disclinations) that are themselves distinguished regions for potential chemical functionalization and nucleators of vesicle budding. Here we report on glassy striped polymer vesicles formed from amphiphilic block copolymers in which the hydrophobic block is a smectic liquid crystal polymer containing cholesteryl-based mesogens. The vesicles exhibit two-dimensional smectic order and are ellipsoidal in shape with defects, or possible additional budding into isotropic vesicles, at the poles.