Surface Engineering Division, National Aerospace Laboratories, Bangalore 560 017, India.
J Colloid Interface Sci. 2009 Nov 15;339(2):454-60. doi: 10.1016/j.jcis.2009.07.064. Epub 2009 Aug 6.
A superhydrophobic sol-gel composite film was fabricated by incorporating hydrophobically modified colloidal zinc hydroxide (CZH) in sol-gel matrix. CZH was prepared by controlled precipitation and modified by treatment with stearic acid. The concentration of stearic acid and stirring time were optimized to obtain modified CZH with very high water contact angle (WCA) of 165 degrees and sliding angle (SA)<2 degrees . X-ray diffraction (XRD) analysis has shown that the crystal structure of CZH was mainly composed of epsilon-zinc hydroxide and the modified CZH indicated the presence of zinc stearate. The modified CZH film exhibited a microstructure which resembled clusters of interconnected rods creating roughness on the film surface. The modified CZH suspension was dispersed in an acid-catalyzed sol of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) and spray-coated on glass slides to prepare sol-gel composite coatings. The concentration of CZH in the composite film was optimized to obtain superhydrophobic surfaces. FTIR spectrum also confirmed the presence of zinc stearate in the composite film. The method is simple and cost-effective and does not involve any expensive chemicals or equipments.
通过在溶胶-凝胶基质中掺入疏水性改性胶体氧化锌（CZH），制备了超疏水溶胶-凝胶复合膜。CZH 通过控制沉淀法制备，并用硬脂酸处理进行改性。优化硬脂酸的浓度和搅拌时间，以获得水接触角（WCA）高达 165 度且滑动角（SA）<2 度的改性 CZH。X 射线衍射（XRD）分析表明，CZH 的晶体结构主要由ε-氧化锌组成，改性 CZH 表明存在硬脂酸锌。改性 CZH 薄膜具有类似于相互连接的棒状簇的微观结构，在薄膜表面产生粗糙度。将改性 CZH 悬浮液分散在酸催化的四乙氧基硅烷（TEOS）和甲基三乙氧基硅烷（MTEOS）溶胶中，并喷涂在载玻片上，制备溶胶-凝胶复合涂层。通过优化复合膜中 CZH 的浓度，获得超疏水表面。FTIR 光谱也证实了复合膜中硬脂酸锌的存在。该方法简单且具有成本效益，不涉及任何昂贵的化学品或设备。
