具有"de Vries-like"特性的液晶设计:SmA和SmC促进元素之间的挫折
Jeffrey C Roberts1, Nadia Kapernaum, Qingxiang Song
1Chemistry Department, Queen's University, Kingston, Ontario K7L 3N6, Canada.
Journal of the American Chemical Society
|December 10, 2009
概括
合成了新的有机纤维素介质素,以实现"de Vries-like"液晶特性,在相位过渡期间显示最小的层收缩. 这些材料具有较低的定向和高的转化顺序,与已知的德弗里斯材料相比.
科学领域:
- 材料科学 材料科学 材料科学
- 液晶是一种液晶.
- 有机化学 有机化学
背景情况:
- 在SmA-SmC相位过渡过程中,De Vries类液晶在SmA-SmC相位过渡过程中表现出极小的层收缩 (<1%).
- 设计这种材料需要平衡竞争的阶段促进结构元素.
- 有机氧为液晶设计提供了一个多功能平台.
研究的目的:
- 合成和描述具有德弗里斯样性质的新型有机纤维素介质物.
- 研究分子结构和液晶相态度之间的关系.
- 评估这些新材料作为现有德弗里斯材料的替代品的潜力.
主要方法:
- 合成两个同源序列的有机纤维素半导体.
- 微角X射线散射 (SAXS) 用于测量层间距 (d) 作为温度的函数.
- 光学倾斜角度测量. 光学倾斜角度测量.
- 减少因子 (R和f) 和热膨胀的分析.
主要成果:
- 介质物3 (n) 呈现SmA-SmC相位过渡,层收缩在0.5%至1.4%之间.
- 在SmC阶段观察到负热膨胀,由于倾斜而导致的平衡层收缩.
- 化合物3 (n) 呈现低定向和高转化顺序,与德弗里斯的行为一致.
- 减少因子 (R) 与已确定的德弗里斯材料相似或低于该材料.
结论:
- 合成的有机纤维素介质素显示出有前途的德弗里斯样特征.
- 观察到的特性归因于结构元素的平衡和负热膨胀.
- 这些材料代表了先进液晶应用的新一类潜在候选材料.
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