基于镍纳米粒子取向性能的柔性液晶显示器件制备研究

This project is about the fabrication of novel flexible liquid crystal displays (LCD) without the alignment layer, on the basis of the nickel nanoparticles (Ni NPs)-induced alignment of LC. The work consists of three parts of contents. Firstly, the Ni NPs with different sizes, morphologies and capping agents will be prepared and characterized in order to get the Ni NPs with excellent performance. Secondly, the LC alignment will be studied and the multiple alignment modes for LCs including homeotropic alignment, homogeneous alignment, hybrid alignment and oblique alignment of LC will be obtained. The key factors of LC alignment induced by Ni NPs will be summarized. Finally, the condition of the fabrication of flexible LCD will be researched and optimized, and the flexible LCD will be obtained. The electro-optical characteristics as well as reliability of the flexible LCD with will be investigated. The relation of the size, morphology and capping agent of the Ni NPs with the LC alignment will be established through this item. The relation of the category of the Ni NPs and the manipulation technique with the alignment mode of LC can be understood, which will initiate a new method for fabrication of novel flexible displays. In addition, the mechanism of Ni NPs-induced alignment of LC will be studied. Since the treatment of the substrate will be avoided in the NPs-induced alignment technique which is necessary in the conventional rubbing process, this study will be of importance for the fabrication of future LCD of high-quality, thin and flexible.

本项目是基于镍纳米粒子的取向性能来制备无取向层的新型柔性液晶显示器件。工作主要分为三部分，首先制备不同形貌、尺寸和修饰剂的多种镍纳米粒子并对这些材料进行成分与结构分析，目的是得到取向性能好的纳米粒子；第二部分是镍纳米粒子诱导液晶定向排列的研究及液晶取向模式的控制，总结出决定液晶取向的关键因素，并实现可控的液晶垂直取向、平行取向、混合取向以及液晶预倾角可以随意调节的倾斜取向模式。最后是探索和优化制备柔性液晶显示器件的条件，最终得到性能良好的柔性显示器件，并研究其电-光性能和可靠性。通过本项目的实施可以建立镍纳米粒子的含量、形貌、修饰剂等因素同液晶取向行为的关系，可以明确纳米粒子的种类、操作工艺与液晶取向模式的关系，为制备新型柔性显示器件开辟一个全新的方法，同时深入研究取向机理。本项目避免了传统的摩擦取向法处理基板的步骤，对于未来制备高效、轻薄、柔性的液晶显示器具有重要意义。

液晶-纳米技术是一个前沿的液晶研究领域。由于纳米微粒的独特性质，将其掺入到液晶显示器中将引发液晶材料大多数物理性能发生改变，导致工作电压和响应时间均下降，并可由此研究出各种显示器件。本项目以高聚物或有机分子为软模板，合成了有机层包覆的 Ni 纳米颗粒、微米花以及纳米花状粒子，并制备液晶/镍纳米粒子复合体系，系统研究了镍纳米粒子的形貌、尺寸、修饰剂、浓度等因素对液晶取向的影响，得到了使液晶平行及垂直取向的镍纳米材料，并深入研究了取向机理。另外，我们将不同形貌的镍纳米颗粒掺杂在液晶中制备了扭曲向列相(TN)显示模式液晶盒，对掺杂镍颗粒的TN模式液晶盒的阈值电压、饱和电压、对比度及响应时间进行了研究。结果表明，掺杂镍颗粒后，液晶的电光性能得到明显改善，阈值电压、饱和电压均有所降低，对比度大幅增加。此外，作为本项目的拓展研究，我们利用镍纳米颗粒的取向性能，制备了一种不需要取向层的新型液晶生物传感器，并将其用于检测生物分子凝血酶，扩展了液晶生物化学传感器的研究与应用。