Optically Isotropic Liquid Crystal Mode Templated by Nanoporous Breath Figure Membrane. Issue 7 (27th January 2022)

• Record Type: Journal Article
• Authors: Shin, Young‐Chul; Park, Ji‐Sub; Joo, Kyung‐Il; Kim, Hyun Gyu; Manda, Ramesh; Choi, Jun‐Chan; Kim, Hak‐Rin
• Is Part Of: Advanced materials interfaces. Volume 9:Issue 7(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-27
• Subjects: depolarization effects -- displays -- liquid crystals -- nanodroplet liquid crystals -- optically isotropic mode; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202101919
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: In this study, a printing‐based scalable method is proposed for the higher density of a liquid crystal (LC) nanodroplet structure suitable for the optically isotropic LC mode where the LC nanodomains are accurately templated by a nanoporous breath figure (BF) membrane. The highly porous BF polymeric template structure is reliably obtained by utilizing self‐structured packing effects of the silica nanospheres achieved by doctor blade coating. A nanocomposite film with densely packed silica nanospheres encapsulated by the UV‐crosslinked polymer matrix is made by controlling the blade coating velocity and blade gap conditions. This provides a higher LC fill‐factor condition of the optically isotropic nanodroplet LC (OI‐NDLC) mode with filling the LCs into the nanopores obtained after selective silica etching. The OI‐NDLC structure templated by the nanoporous BF membrane made with the silica nanospheres of 300 nm can effectively resolve the scattering‐induced optical loss and depolarization issues observable in the OI‐NDLC mode prepared by conventional phase separation approaches due to the sufficiently reduced LC droplet size. The structure exhibits a much‐improved light leakage level in the field‐off optically isotropic state, a higher transmittance level as the field‐induced Kerr operation, and resultant improved contrast ratio properties. Abstract : An optically isotropic liquid crystal (LC) mode templated by a nanoporous breath figure membrane is presented by utilizing the self‐structured high density of nanosilica packing of doctor blade coating. Due to the high fill factor of the LC nanodroplets obtained at the sufficiently suppressed depolarization effects, high Kerr effects ( K Kerr = 5.75 × 10 −9 m V −2 ) are achievable at a contrast ratio of 208.6:1 with the scalable printing approach.