Electrically responsive structural colors from colloidal crystal arrays of PS@PANI core–shell nanoparticles

Photonic display cell that produce structural colors over a wide visible spectrum have been self-assembled from core–shell PS@PANI nanoparticles using a natural sedimentation method. A series of core–shell PS@PANI nanoparticles were prepared by deposition of PANI shells on the surfaces of the PS cores through an in situ polymerization of aniline monomers. The thickness of PANI shells can be well controlled by changing the weight ratio of aniline and PS nanoparticles . The response structure color characteristics of photonic display cell were investigated under different electric field. The position of these reflection peaks varied with the change of the external electric field in wide visible spectrum. The structurally colored materials exhibited colors resulting from the combined effects of the ordered colloidal crystal arrays and the electrochromism of PANI shell.