Fabrication of Reflective Color Films from Cellulose Derivatives

In this study, we fabricated the reflective color films of lyotropic cholesteric liquid crystals (CLCs) by using a hydroxypropyl cellulose (HPC) derivative and water. When HPC derivatives possessing acryloyl esters in the side chains (HPC-AcE) were completely dissolved in water to form the lyotropic CLC (HPC-AcE_H2O), we could observe Bragg reflection in the visible wavelength range at room temperature. Furthermore, after the lyotropic CLC mixtures were irradiated with UV light, the reflection colors could be preserved at room temperature. This report has established an important guideline to fabricate the colored CLC cellulose films with safety and low risks for both human being and global environment from naturally occurring polymers and water.