Hye-Yun Ko (PhD candidate), a researcher in the research team led by Professor Kwang‑Woon Jeong at Jeonbuk National University (JBNU) (College of Engineering, Department of Polymer -Nano Science &Technology; Graduate School, Department of Nano Convergence Engineering), has developed an encryption polymer film applicable to display and encryption-film fields and published a paper in a leading international journal.

The team led by Professor Kwang‑Woon Jeong developed an encryption polymer film capable of anisotropic biaxial optical absorption in a single layer, using a newly synthesized diacetylene-based material.

Optical films are typically produced by aligning dichroic molecules to impart polarization through differences in absorbance between the molecules' long and short axes. However, because the absorption axis of the aligned molecules exists in only one direction, the films only exhibit differences in color brightness depending on the polarization direction of light.

To realize polarization-dependent multicolor behavior in a single-layer polymer film, the team induced orthogonal orientation between the absorption axes of a host–guest complex and polydiacetylene, achieving biaxial anisotropic optical absorption.

This study was published in the Journal of the American Chemical Society (JACS, Impact Factor = 15.0), the flagship journal of the American Chemical Society. 

The polymer film produced in this study is expected to be applicable to multiplexed encryption systems and, as a thin film, to display and encryption-film applications through its biaxial anisotropic optical absorption.

Hye-Yun Ko, the lead author who led the research, said, 'We aimed to address the limitations of existing polarization materials from a new perspective,' and added, 'I hope this technology will contribute to the development of advanced optical materials.'

Meanwhile, this research was conducted with support from the U.S. Air Force Research Laboratory and through the Basic Research Laboratory Support Program and the Mid‑career Researcher Support Program of the National Research Foundation of Korea.