UV-Triggered Optical Asymmetry Modification of Gold Nanorods Helical Assemblies in a Cholesteric Liquid Crystal Host

The creation and modulation of chirality innanomaterials is a well-established and widely applied concept. Nevertheless, the direct approach of dynamically tuning their morphological asymmetry at thenanoscale to reveal their optical asymmetry variations is yet less well-implemented. The helical templating of nanomaterials within a cholesteric liquidcrystal (CLC) host and the exploitation of their optical asymmetry change inconjunction with the host represent a means of circumventing technological limitations. In this study, a blending approach is employed to investigate the helical assemblies of gold nanorods (Au NRs) within a photo-tunable CLC host, followed by their morphological asymmetry modulation through the use of UV irradiation. The results demonstrated that the optical asymmetry of the Au NR shelical assemblies increased in response to a reduction in pitch and the distance between the Au NRs, regardless of the azimuthal variations.Furthermore, the Au NRs blended with CLCs exhibited excellent and stable reflective properties comparable to those of conventional CLCs. Additionally,they can modulate the light flux of incident light at NIR wavelengths. The integrated modulation of reflection and transmission by Au NRs helical assemblies and CLC hosts represents a promising avenue for future research inthe field of multi-level information encryption. This work employs a blending approach to study the helical assemblies of gold nanorods (Au NRs) within a phototunable cholesteric liquid crystal (CLC) host and demonstrates the modulation of their morphological asymmetry by the use of UV irradiation and discusses the resulting optical asymmetry changes in extinction spectra, CD spectra, near-field enhancement distributions and g-factor. image