Structural coloration in textiles

Abstract

Conventional textile coloration is a wet process involving high levels of water and chemicals consumption and wastewater generation. However, colour in textiles can also be generated by other mechanisms such as: absorption, emission, diffraction, interference and photochromism. Chromotropic effect refers to reversible colour transformation due to external chemical or physical influence. Photonic crystals are an important class of chromotropic materials. Colloidal crystals with a periodicity on the scale of half the wavelength of visible light exhibit structural colours similar to natural opals due to a diffraction effects that result in the appearance of a photonic band gap that forbids propagation of certain wavelengths. Structural colouration is emerging as an innovative technology to produce colourful textiles materials. Various colours impossible to reproduce by chemical coloration can be created by modifying the periodicity of the nanostructures or the environmental conditions using a single material. Photonic crystals can be applied on textile fabrics by colloid self-assembly and the structural colours can be controlled by adjusting the microspheres size and the viewing angles.