A research team led by Professor Kwang‑woon Jeong at Jeonbuk National University (JBNU), Department of Polymer -Nano Science &Technology and Graduate School, Department of Nano Convergence Engineering, has synthesized a novel photoresponsive liquid‑crystal compound and elucidated its various optical behavior changes under UV irradiation. 

The synthesized photoresponsive liquid‑crystal compound can realize five distinct optical properties from a single dye molecule, raising strong expectations as a next‑generation encryption ink.

The research was recognized for its excellence and selected as the cover article of the renowned international materials‑science journal Advanced Science (IF=15.1, top 6.8%) on March 20, 2024.

The team proposed a liquid‑crystal molecule combining two chromophores—cyanostilbene, which enables photoisomerization and exhibits aggregation‑induced emission characteristics, and diacetylene. The molecule's optical properties changed via different photochemical reactions when exposed to two UV wavelengths, 254 nm and 365 nm. By applying the two UV sources sequentially or by a thermal stimulus, it was possible to realize additional optical properties.

Notably, the team leveraged these advantages to successfully demonstrate films patterned with multiple optical properties as well as encryption codes with various decoding pathways.

This study is significant because it demonstrates five optical properties from a single dye molecule, and it is garnering strong expectations as a next‑generation encryption ink.

Dr. Ja‑hyun Gu, the first author who led the study, said, "This research once again made me appreciate the subtleties of molecular design," adding, "I hope this technology will open new horizons in dye‑based optics." 

Meanwhile, this research was carried out with support from the Basic Research Laboratory Support Program and the Mid‑Career Researcher Support Program of the National Research Foundation of Korea.