Shaping nanoparticle fingerprints at the interface of cholesteric droplets

TL;DR

This paper demonstrates how tuning surfactants and chiral dopants in cholesteric liquid crystal emulsions enables dynamic, reconfigurable nanoparticle patterning at interfaces, with potential applications in optical and energy materials.

Contribution

It introduces a method to control nanoparticle assembly at liquid crystal interfaces through surfactant and dopant tuning, creating reconfigurable and shape-retaining nanostructures.

Findings

Nanoparticle patterns are tunable via surfactant and chiral dopant concentrations.

Particles can be crosslinked and manipulated to retain shape.

Interfacial assemblies are influenced by elastic patterns from geometric frustration.

Abstract

The ordering of nanoparticles into predetermined configurations is of importance to the design of advanced technologies. In this work, we moderate the surface anchoring against the bulk elasticity of liquid crystals to dynamically shape nanoparticle assemblies at a fluid interface. By tuning the degree of nanoparticle hydrophobicity with surfactants that alter the molecular anchoring of liquid crystals, we pattern nanoparticles at the interface of cholesteric liquid crystal emulsions. Adjusting the particle hydrophobicity more finely further modifies the rigidity of assemblies. We establish that patterns are tunable by varying both surfactant and chiral dopant concentrations. Since particle assembly occurs at the interface with the desired structures exposed to the surrounding phase, we demonstrate that particles can be readily crosslinked and manipulated, forming structures that retain their shape under external perturbations. This study establishes the templating of nanomaterials into reconfigurable arrangements. Interfacial assembly is tempered by elastic patterns that arise from the geometric frustration of confined cholesterics. This work serves as a basis for creating materials with chemical heterogeneity and with linear, periodic structures, essential for optical and energy applications.