Organized Self-Emulsification toward Structural Color

TL;DR

This paper presents a scalable method to create structurally colored materials by controlling water-in-oil-in-water emulsions with bottlebrush copolymers, enabling tunable bright colors through nanopore array formation.

Contribution

It introduces an organized self-emulsification mechanism using bottlebrush copolymers to produce tunable structural colors in a scalable way.

Findings

Nanoscale water droplets form ordered arrangements within oil droplets.

Solid microspheres with hexagonal nanopore arrays exhibit bright structural colors.

Color can be precisely tuned across the visible spectrum by adjusting molecular contour length.

Abstract

The formation of water-in-oil-in-water (W/O/W) double emulsions can be well-controlled through an organized self-emulsification mechanism in the presence of rigid bottlebrush amphiphilic block copolymers. Nanoscale water droplets with well-controlled diameters form ordered spatial arrangements within the micron-scale oil droplets. Upon solvent evaporation, solid microspheres with hexagonal close packed nanopore arrays are obtained resulting in bright structural colors. The reflected color is precisely tunable across the whole visible light range through tailoring contour length of the bottlebrush molecule. In-situ observation of the W/O interface using confocal laser scanning microscopy provides insights into the mechanism of the organized self-emulsification. This work provides a powerful strategy for the fabrication of structural colored materials in an easy and scalable manner.