新的SmCG阶段在结合的曲核心液晶中,具有分支的西洛末端组
Wei-Hong Chen1, Wei-Tsung Chuang, U-Ser Jeng
1Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, 30049, Taiwan.
Journal of the American Chemical Society
|August 30, 2011
概括
这项研究揭示了新的曲核心液晶相 (SmCG),由结合和单元诱导. 这些相表现出独特的二维结构和铁电-抗铁电切换行为,提供了新的材料可能性.
科学领域:
- 材料科学 材料科学 材料科学
- 有机化学 有机化学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 曲核心分子以独特的液晶相而闻名.
- 结合和终端组显著影响等态性质.
- 锡洛干单元可以引入特定的结构和电子特征.
研究的目的:
- 合成和研究新型曲核心分子与键和共价键素单元.
- 探索结和分支的素终端单元对等态性质的影响.
- 描述由此产生的液晶相及其结构排序.
主要方法:
- 三种类似的曲核分子的合成:H-SiO,C-SiO和H-Alk.
- 使用差分扫描热量测量和极化光学显微镜等技术进行半态性属性调查.
- 使用现场广角X射线散射 (WAXS) 的结构分析.
- 光谱分析 (FTIR,拉曼) 了解分子相互作用.
- 通过切换电流测量对电光学属性的研究.
主要成果:
- H-SiO 呈现了具有高度排序的 2D 结构的新型一般倾斜 smectic (SmCG) 阶段,与 C-SiO 和 H-Alk.的典型 SmCP 阶段不同.
- SmCG阶段过渡涉及从2D调制的带转变为高度排序的层,由增加键强度驱动.
- 电场对齐显示了倾斜角度的降低,这归因于竞争的键和素微分离.
- 在SmCG阶段观察到铁电到反铁电到铁电的过渡,表明集体极转换.
结论:
- 具有高度排序的2D结构的新型SmCG阶段在曲核心与结合液晶复合体 (H-SiO) 中成功诱导.
- 键和分支的素单元之间的相互作用对于形成这些独特的中相相至关重要.
- 观察到的铁电-反铁电切换机制为复杂的液晶系统的极性行为提供了洞察力.
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