Study on flow and structure change on drawing and drying process for production of functional thin film

本研究主要探讨彩色液晶溶液涂布及干燥成膜过程。在玻璃板上通过剪切变形取向的有色液晶溶液薄膜具有光学各向异性。使用这种方法，二向色性或双折射膜和太阳能电池板将比它们当前的方法更容易生产，并且制造成本将降低。镀膜装置，它持有一个平板玻璃和滑动它以恒定的速度进行了这项调查。涂布器设置在玻璃板上，玻璃板具有1 - 10 μ m的薄间隙。将预定量的样品液体滴加到玻璃板上，并用涂布器涂布。涂在玻璃上的薄液膜经自然陈化后成为薄膜。用偏光显微镜观察干燥过程，用激光位移传感器测量干燥过程中液膜厚度的变化。用旋光法测量了薄膜的二向色性和双折射等光学各向异性。在液膜干燥中，膜厚度的减小速度不是恒定的，并且以恒定的频率振动。这与在本研究中观察到的通过干燥的液体的微流动运动的发生有关。该薄膜表现出强的二向色性，但它包括降低光学膜的质量的带织构。在所有的实验条件下，带状织构的产生。涂布速度和涂布器的差距不影响薄膜的质量

In this study, the thin film formation process by application and drying of chromonic liquid crystal solution was investigated. The thin film of chromonic liquid crystal solution which is oriented by shear deformation on a glass plate has optical anisotropy. Using this process, dichroic or birefringence films and solar battery panels would be produced easier than their current processes, and manufacturing cost would be reduced. The coating device which holds a flat glass plate and slides it with a constant velocity was made for this investigation. An applicator is set up the glass plate with thin gap which is 1 to 10 □m. The predetermined amount of the sample liquid is added dropwise on the glass plate, and it is painted with the applicator. The painted thin liquid film on the glass becomes thin film by natural seasoning. The process of drying is observed by polarized microscope and the decreasing thickness of the liquid film is measured by laser displacement sensor. The optical anisotropy, such as dichroism and birefringence, of the thin film is measured by polarimetry technique. In the liquid film drying, the reduction velocity of the film thickness is not constant and vibrates with a constant frequency. It is related to occurrence of the micro flow motion of the liquid by drying which was observed in this study. The thin film exhibits strong dichroism but it includes the band-texture which reduces the quality of the optical film. At all experimental conditions, the band-texture was generated. The coating speed and the gap of the applicator did not influence the quality of the thin film