超疏水氧化鋅反蛋白石結構製備及其電濕潤之應用

Abstract

本研究成功地以簡單快速的方法製備氧化鋅反蛋白石(ZnO Inverse Opal，ZIO)結構，並利用其奈米結構加上低表面能分子的修飾，展現出明顯的介電濕潤(Electro-Wetting on Dielectric；EWOD)效應。以無乳化聚合法合成出粒徑720 nm的聚苯乙烯(PS)微球，並利用電泳沉積法(Electrophoretic Deposition，EPD)製備fcc整齊排列的PS膠體晶體。接著以定電位電鍍ZnO至膠體晶體孔隙中。將PS球移除後，即可獲得有序排列的ZIO結構。以單分子層吸附的方式，將FAS-17吸附於ZIO結構表面，可得到具有超疏水(Superhydrophobic)性質的ZIO結構。將水珠滴在超疏水ZIO結構上，外加交流電壓，隨著電壓增加，觀察水珠形貌的改變，可發現ZIO結構由超疏水性轉變為親水性。此外，藉由製備不同厚度的反結構，可以得到不同EWOD效果，且從電位和接觸角的關係中，能夠看出液滴在外加電位時，突破能量的障礙，由Cassie轉換為Wenzel的狀態。

Polystyrene (PS) microspheres were synthesized by an emulsifier-free polymerization method with narrow particle size distribution. Electrophoretic deposition (EPD) technique was adopted to produce large-scaled PS colloidal crystals with reduced defects on ITO substrates. Subsequently, ZnO was electroplated into the interstitial voids within colloidal crystals. After the removal of PS template with sintering and chemicals, ZnO inverse opals were successfully formed. Both opal and inverse opal films exhibited characteristic photonic band gaps. ZnO inverse opals were surface-modified by fluoroalkylsilane (FAS-17) to render desirable super-hydrophobicity and self-cleaning effect, showing a contact angle (CA) of 160° and small sliding angle (SA). The surface experienced a dramatic change in wettability from super-hydrophobic to hydrophilic states when the electric potential was applied across the solid/liquid interface. We explored various electro-wetting effects on a variety of thickness. The threshold between Cassie and Wenzel models for the liquid droplets was determined by analyzing the electro-wetting curves.