液晶气相沉积玻璃中高度有序的近层状堆积结构
Highly organized smectic-like packing in vapor-deposited glasses of a liquid crystal
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中文总结 AI 辅助
研究人员制备气相沉积伊曲康唑液晶玻璃，发现衬底温度高于Tg时所得玻璃结构有序性优于热退火膜，为优化有机光电器件活性层分子堆积提供新策略。
中文摘要 AI 辅助
以近晶型液晶形成模型分子伊曲康唑为研究对象，通过气相沉积法在衬底温度范围为T衬底=0.78Tg至1.02Tg的衬底上制备其玻璃态，其中Tg=330K为玻璃化转变温度。采用X射线散射技术对薄膜进行表征。当衬底温度接近或低于Tg时，可制备出具有层状近晶型结构的玻璃态，且通过选择衬底温度可使层间距产生16%的可调范围。值得注意的是，在衬底温度高于Tg时制备的玻璃态，其结构有序性远优于热退火处理的薄膜。这些结果可通过基于分子优选取向和自由表面处分子运动增强的机理解释，表明玻璃态中的分子有序性与衬底处的锚定偏好无关。上述结果为优化有机电子和光电器件活性层内的分子堆积提供了新策略。
英文摘要
Glasses of a model smectic liquid crystal-forming molecule, itraconazole, were prepared by vapor deposition onto substrates with temperatures ranging from Tsubstrate = 0.78 Tg to 1.02 Tg, where Tg = 330 K is the glass transition temperature. The films were characterized using x-ray scattering techniques. For Tsubstrate near and below Tg, glasses with layered smectic-like structures can be prepared and the layer spacing can be tuned by 16% through choice of Tsubstrate. Remarkably, glasses prepared with Tsubstrate above Tg exhibit much higher structural organization than a thermally annealed film. These results are explained by a mechanism based upon preferred molecular orientation and enhanced molecular motion at the free surface, indicating that molecular organization in the glass is independent of the anchoring preferred at the substrate. These results suggest new strategies of optimizing molecular packing within active layers of organic electronic and optoelectronic devices.
