Light Intensity-Selective Photopolymerization and Photoisomerization for Creating Colorful Polymer-Stabilized Cholesteric Liquid Crystal Patterns

Autor: Runwei Yu, Yu Cao, Kai Chen, Yi Li, Wei Liu, Baozong Li, Hongkun Li, Yonggang Yang
Rok vydání: 2022
Předmět:
Zdroj: ACS Applied Materials & Interfaces. 14:38228-38234
ISSN: 1944-8252
1944-8244
DOI: 10.1021/acsami.2c10763
Popis: Polymer-stabilized cholesteric liquid crystal (PSCLC) films have been widely studied for their application as sensors, polarizers, and reflective windows. However, the preparation of programmable and colorful patterns based on the structural color is still challenging. Herein, the photochromic CLC mixtures were prepared by adding a photoisomerizable chiral additive (CA) and a photoinitiator in the nematic liquid crystal LC242. Under UV irradiation with weak intensity, photoisomerization of the CA was carried out and photopolymerization was suppressed by oxygen inhibition. With extending the irradiation time, the helical pitch of the CLC film increased and the selective Bragg reflection band tended to redshift. Under strong UV irradiation, oxygen inhibition was overcome and photopolymerization dominates the reaction. Therefore, the colorful-patterned PSCLC films were able to be prepared using masks. The results shown here not only give us a better understanding of the effect of oxygen inhibition but also lay the foundations for practical applications such as decoration and optical devices.
Databáze: OpenAIRE