Light- and Humidity-Responsive Chiral Nematic Photonic Crystal Films Based on Cellulose Nanocrystals

• DOI: 10.1021/acsami.0c05139
• Publication Date: 2020-05-04T07:49:42Z
• Authors: Huanghuang Chen; Aiqin Hou; Changwu Zheng; Jing Tang; Kongliang Xie; Aiqin Gao
• Keywords: Structural Coloration

Light- and humidity-responsive chiral nematic photonic crystal (PC) films containing cellulose nanocrystals (CNCs) were fabricated. A photoactive polymer with hydrophilic groups, poly-(3,3'-benzophenone-4,4'-dicarboxylic acid dicarboxylate polyethylene glycol) ester, was coassembled CNCs to form flexible iridescent a tunable order. In the coassembly process, intermolecular hydrogen bonds of weakened, which facilitated fine regulation PC nanostructure. The displayed sensitive responses both light humidity. With increasing humidity from 30 100%, helix pitch increased 328 422 nm. color changed blue green, yellow, orange, dark red relative Over 15 min irradiation, absorption intensity gradually. reversible. maintained their variable cholesteric liquid texture helical lamellar structure after irradiation at different humidities. These are expected be useful in intelligent coatings 3D printing.