Epure Elena-Luiza, Stoica Iuliana, Albu Raluca Marinica, Hulubei Camelia, Barzic Andreea Irina
Faculty of Chemical Engineering & Environmental Protection, Gheorghe Asachi Technical University, 700050 Iasi, Romania.
Petru Poni Institute of Macromolecular Chemistry, 41A Aleea Grigore Ghica Voda, 700487 Iasi, Romania.
Nanomaterials (Basel). 2021 Nov 18;11(11):3107. doi: 10.3390/nano11113107.
The operability of liquid crystal displays is strongly impacted by the orientation aspects of nematics, which in turn are affected by the alignment layer surface features. In this work, two polyimide (PI) structures are obtained based on a cycloaliphatic dianhydride and aromatic or aliphatic diamines with distinct flexibility. The attained PI films have high transmittance (T) for visible radiations, i.e., at 550 nm T > 80%. Here, a novel strategy for creating surface anisotropy in the samples that combines rubbing with a cloth and stretching via pressing is reported. Birefringence and atomic force microscopy (AFM) scans reveal that the generated orientation of the chains is affected by the chemical structure of the polymer and order of the steps involved in the surface treatment. Molecular modeling computations and wettability tests show that the PI structure and produced surface topography are competitive factors, which are impacting the intensity of the interactions with the nematic liquid crystals. The achieved results are of great relevance for designing of reliable display devices with improved uniform orientation of liquid crystals.
液晶显示器的可操作性受到向列相取向方面的强烈影响，而向列相的取向又受取向层表面特征的影响。在这项工作中，基于具有不同柔韧性的脂环族二酐和芳香族或脂肪族二胺获得了两种聚酰亚胺（PI）结构。所获得的PI薄膜对可见辐射具有高透过率（T），即在550nm处T>80%。在此，报道了一种在样品中产生表面各向异性的新策略，该策略将用布摩擦与通过压制拉伸相结合。双折射和原子力显微镜（AFM）扫描表明，链的生成取向受聚合物化学结构和表面处理所涉及步骤顺序的影响。分子建模计算和润湿性测试表明，PI结构和所产生的表面形貌是相互竞争的因素，它们影响与向列型液晶相互作用的强度。所取得的结果对于设计具有改善的液晶均匀取向的可靠显示装置具有重要意义。
