Tunable and saturated structural colors from carbon nanotubes incorporated highly ordered photonic opals

TL;DR

This paper presents the fabrication of high-quality 3D photonic opals with tunable and saturated structural colors achieved by incorporating a tiny amount of carbon nanotubes, enabling potential applications in sensing and structural health monitoring.

Contribution

It introduces a novel method of incorporating carbon nanotubes into photonic opals to produce tunable, saturated colors without disrupting lattice order, enhancing their functional applications.

Findings

Carbon nanotubes induce dramatic color changes at 0.01% incorporation.

Color tunability correlates with incident angle following Bragg-Snell law.

Photonic opals demonstrate mechanochromic sensing capabilities.

Abstract

Synthetic opals, based on self-assembly of polymeric nanoparticles generally produces fainted/pale structural colors due to too many lattice flaws in the structures. Here we produces carbon nanotubes (CNTs) incorporated high quality 3D photonic opals (PC-CNT) by evaporative self-assembly. Although the CNTs make up only 0.01% of the fabricated photonic opal, their controlled incorporation has dramatic effect to change the color of the photonic crystals from milky white to intense red. Microscopic study suggest that CNT incorporation did not affect the lattice ordering of the photonic crystals. The tunability of structural colors, as a function of incident angle, were tested and varied against Bragg-Snell law. Furthermore, we tested mechanochromic sensing of the photonic opals, demonstrating their potential as visual indicators. This tunable PC-CNT brings many possibilities including strain sensing or structural health care monitoring, as well as being of fundamental interest.