液晶与显示2024，Vol.39Issue(12)：1679-1688,10.DOI:10.37188/CJLCD.2024-0207
蓝相液晶逐层相变过程的表征与机理探究
Characterization and mechanism investigation of layer-by-layer phase transition process in blue phase liquid crystals
摘要
Abstract
Blue-phase liquid crystals are self-assembled three-dimensional soft photonic crystals with a wide range of applications in the fields of sensing and display,information encryption,anti-counterfeiting,and optical devices.However,the research on the blue-phase phase transition is not sufficient.In this paper,phase transition process was investigated for the single-domain BPⅡ to BPⅠ(a wide temperature interval 2.5℃)based on optical and structural features,and the mechanism of phase transition behaviors at each stage was elucidated by using the crystal nucleation and growth theory.BPⅡ-BPⅠ coexistence stage was proved by the bimodal peaks of the reflectance spectra and the superposition of circles and quadruple arcs in the Kossel diffraction pattern,which indicated simple superposition of the BPⅡ and BPⅠphase state.The lamellar growth structures of the BPⅡ,BPⅡ-BPⅠ,and BPⅠ phases were observed using polarized light microscopy and low-voltage scanning electron microscopy.BPⅠ was found to nucleate and grow epitaxially from the edge dislocations of BPⅡ,and its phase transition process transformed layer by layer from top to bottom of the cell.The edge dislocations and screw dislocations moved and merged at the BPⅠ stage,transforming the texture into a concentric ring.This study is of great significance both for enrich the theory of blue phase transition and guiding the preparation of large-area single-domain blue phases.关键词
蓝相/相变/层状结构/晶体成核生长/位错Key words
blue phase/phase transition/laminar structure/crystal nucleation growth/dislocations分类
数理科学引用本文复制引用
郑成林,孙莉,王京霞,江雷..蓝相液晶逐层相变过程的表征与机理探究[J].液晶与显示,2024,39(12):1679-1688,10.基金项目
国家自然科学基金(No.52373001,No.51873221,No.52073292,No.51673207,No.51373183,No.21988102) Supported by National Natural Science Foundation of China(No.52373001,No.51873221,No.52073292,No.51673207,No.51373183,No.21988102) （No.52373001,No.51873221,No.52073292,No.51673207,No.51373183,No.21988102）
