Preparation of the Color Films from Cellulose Derivatives in a Diacrylate Liquid

In this study, we fabricated the multi-colored films of lyotropic cholesteric liquid crystals (CLCs) prepared from a hydroxypropyl cellulose (HPC) derivative by photopolymerization of a diacrylate liquid monomer for color image applications. When a hydroxypropyl cellulose derivative tethering propionyl side chains (HPC-PrE) was completely dissolved in a liquid monomer of 1,4-bis(acryloyloxy)butane (BAOB) to prepare lyotropic CLC (HPC-PrE_BAOB), we could observe Bragg reflection in the visible wavelength range at room temperature. Photopolymerization of BAOB in the lyotropic CLC mixture gave rise to fabrication of robust solid-state CLC films with reflection colors. Furthermore, we found that the reflection wavelength is tunable by controlling the light intensity of irradiation UV light, thereby enabling the facile fabrication of multi-colored films by the photolithographic technique. The present report opens promising ways to design and produce intriguing photonic devices by utilizing the environmentally-friendly and safe natural polymer of cellulose.