Control of surface texture of coating films prepared by the sol-gel method

在本研究中，通过控制溶胶-凝胶法制备的涂层膜的表面结构，获得了新的功能材料。沸水浸泡后，在SiO_2-TiO_2凝胶膜表面形成锐钛矿纳米晶。锐钛矿沉淀膜具有较高的光催化活性。凝胶膜在60℃干燥后，在55℃的热水中浸泡也能形成锐钛矿晶体。研究发现，在振动作用下，薄膜在热水中浸泡可形成二氧化钛纳米片。纳米二氧化钛片表面粗糙度小，具有超亲水性。即使在黑暗的地方保存了2000多小时，这些特性也保持了下来。当紫外线照射在以乙酰乙酸乙酯改性的醇钛制备的SiO_2-TiO_2凝胶膜上时，辐照面积对各种溶剂的溶解度变得很小。通过光掩膜对SiO_2TiO_2凝胶膜进行紫外照射，并对未照射区域进行蚀刻，得到了SiO_2TiO_2凝胶膜的微观形貌。将微图案化的SiO_2-TiO_2凝胶膜浸泡在热水中，在微图案化表面形成锐钛矿纳米晶体。用乙酰乙酸乙酯改性的al -醇盐制备的Al_2O_3凝胶膜，在40℃热水中浸泡后，表面粗糙度约为20 ~ 50 nm。另一方面，粗糙度小的表面反射率很低，波长区域很宽。

In the present study, surface texture of the coating films prepared by the sol-gel method has been controlled to obtain new functional materials.1. Anatase nanocrystallites were found to be formed on the surface of SiO_2-TiO_2 gel films through immersion in boiling water. The anatase precipitated films showed high photocatalitic activity. Anatase crystals were formed even through the immersion of the gel films in hot water of 55 ℃ after being dried at 60 ℃. Titania nano-sheets were found to be formed through the immersion of the films in hot water under vibration. The surface with titania nano-sheets has a small roughness, and shows superhydrophilic properties. These properties were kept even after being kept under a dark place for more than 2000 h.2. When UV-light was irradiated on the SiO_2-TiO_2 gel films prepared from titanium alkoxide modified with ethyl acetoacetate, the solubility of irradiated area for various solvents become very small. By the irradiation of UV-light through a photo mask and etching of unirradiated area, micropatterns of SiO_2TiO_2 gel films were obtained. By immersion of the micropatterned SiO_2-TiO_2 gel films in hot water, anatase nano-crysltallites were formed on the micropatterned surface.3. Small roughness of about 20 to 50 nm was found to be formed by immersion of Al_2O_3 gel films prepared from Al-alkoxide modified with ethyl acetoacetate, in hot water at 40 ℃. On the other hand, the surface with the small roughness shows very low reflectivity with the wide wavelength region.