利用溶膠凝膠法與噴塗技術之玻璃基板表面改質

Surface modification on a glass surface with a combination technique of　sol-gel and air brushing processes

蔡孟育(Meng-Yu Tsai)

指導教授 ： 陳炳煇

國立臺灣大學/工學院/機械工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.10406

摘要

在日常生活所見到的蓮花葉片，因為其表面具有奈米與微米的複合型結構以及表面的蠟質，故常可見到水珠幾乎呈現球狀在蓮花葉上，水珠流動的過程便能將表面之灰塵給帶走，這樣的超疏水與表面自潔的特性便是著名的蓮花效應。
　　藉由此自然界的特性，激起建立類似的仿生結構在玻璃基板上之動機。材料要能表現出超疏水的特性在於降低材料的表面能。方式有二：第一，在表面建立粗糙度，而這些粗糙度會形成許許多多的孔隙並且將空氣困在其中，使得水分子傾向於聚在一起形成小水珠。；第二，在表面塗佈低表面能的材料，亦即降低材料之表面張力。在這兩大方向之下，本研究選用奈米級與微米級之二氧化矽顆粒作為建立表面粗糙度的關鍵材料，並且利用矽烷類化合物(TEOS)做為接合劑，以利顆粒與玻璃表面接合；接著利用適當的噴塗技術與合宜的烘烤溫度將顆粒與接合劑均勻的塗佈和接合在玻璃表面上，如此便能建立出高透光度與具有粗糙度的表面。最後再進行疏水與疏油材料(PFCS)的表面處理，一方面增加其疏水特性使其能表現出超疏水，另一方面也增加表面的耐久性與耐刮性甚至是疏油性，使其能長時間的面對紫外光、高低溫變化以及汙垢之環境。

關鍵字

超疏水 ； 透光 ； 玻璃 ； 溶膠凝膠法 ； 二氧化矽 ； 噴塗

並列摘要

This study aims to fabricate the optically transparent superhydrophobic silica based films on glass surface with optimized adhesion and hardness. The hydrophobic performance is determined by two factors i.e. surface roughness and surface energy. To get a superhydrophobic surface, enhancing the roughness of the glass surface and lowering the surface energy are essential. A silane coupling agent, tetraethoxysilane (TEOS), effectively bonds silica particles onto the glass substrate. Desired surface roughness was obtained by adjusting nano silica particles concentration of the precursors prepared by the sol-gel process. 6.38% of nano silica particles concentration was found to be sufficient to create a rough surface, while retaining enough transmittance. Silica suspension was coated onto the glass substrate by the dip-coating and air-brushing methods. Both methods can deposit a uniform, transparent coating on the glass substrate. Diluting the precursor by adding ethanol or a mixture of D.I. water and ethanol at specific volumetric ratio further improved the transmittance and superhydrophobicity efficiency. The coating with optimized adhesion and hardness was obtained by the sol-gel process with the careful control of hydrolysis, condensation reactions, and appropriate baking treatment. To obtain superhydrophobic surface, the baked glass was further treated with trichloro (1h, 1h, 2h, 2-perfluorooctyl) silane (PFCS), trimethoxyphenylsilane, octadecyltrimethoxysilane, or triethoxy (octyl) silane by immersing, air brushing, or quick dipping method.
The results showed that as the silica particle concentration and the thickness of the coating were increased, the surface roughness was enhanced. Rougher surface displayed a higher superhydrophobicity and lower transmittance. Therefore, the concentration of silica particle, thickness of coatings, and the ratio of ethanol and D.I. water are of great importance to deposit a transparent, superhydrophobic coating on glass. A superhydrophobic (CA= 151.7°) and nearly transparent (T~87%) surface has been successfully made on a glass by the precursor diluted by a solution containing 60 ml D.I. water and 20 ml ethanol, followed by the post treatment with trichloro (1h, 1h, 2h, 2-perfluorooctyl) silane using the quick-dip method.

並列關鍵字

superhydrophobic ； transparent ； glass ； sol-gel ； silica ； air-brushing

參考文獻

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