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

本研究以含铬液晶溶液为研究对象，研究了涂布和干燥形成薄膜的过程。在玻璃板上剪切变形取向的显色液晶溶液薄膜具有光学各向异性。使用这种工艺，二向色性或双折射薄膜和太阳能电池板的制造将比目前的工艺更容易，并将降低制造成本。为此研制了一种固定平板玻璃并以恒定速度滑动的镀膜装置。在玻璃板上设置涂布器，涂布器具有1~10米的薄间隙，将预定数量的样品液体滴加到玻璃板上，并用涂布器涂抹。玻璃上涂有薄薄的液体膜，经过自然调味后就变成了薄膜。用偏光显微镜观察了干燥过程，用激光位移传感器测量了液膜厚度的减小。用旋光法测量了薄膜的光学各向异性，如二向色性和双折射。在液膜干燥过程中，液膜厚度的减速不是恒定的，而是以恒定的频率振动。这与本研究中观察到的液体在干燥过程中发生的微流运动有关。薄膜表现出强烈的二向色性，但它含有带状织构，这降低了光学薄膜的质量。在所有实验条件下，都产生了带状织构。涂布速度和涂布器的间隙不影响薄膜的质量

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