Preparation of TiN-PVP/Polymer-Dispersed Liquid Crystal Composite Films and Studies on Electro-Optical Properties and Optical Modulation

Polymer-dispersed liquid crystals (PDLCs) exhibiting electro-optical (E-O) conversion capabilities facilitate modulation across the ultraviolet (UV) to infrared (IR) spectrum. In this study, a bilayer TiN-PVP/PDLC composite film device was prepared by utilizing commercially available polymers and nanoparticles to enhance UV and IR shielding efficacy. By optimizing the ratio of polymer monomers to liquid crystals within the PDLC layer, superior E-O characteristics were achieved, which were further augmented through the incorporation of a TiN-PVP film. The results showed that the TiN-PVP/PDLC composite films had the maximum contrast ratio when the TiN doping content was 1.5 wt %. Notably, the TiN-PVP/PDLC composite film demonstrated significant thermal and UV shielding performance under IR and UV irradiation, with thermal shielding efficiencies exceeding 60% in both the off and on states, while UV shielding exhibited commendable values of 96.8% and 56.9% in the corresponding states. This facilely synthesized TiN-PVP/PDLC composite film holds significant promise for passive cooling applications in smart window technologies and architectural structures.