以二步驟溶膠-凝膠法製備超疏水薄膜

本研究探討以四乙氧基矽烷 (Tetraethoxysilane, TEOS) 為單體，利用二步驟溶膠-凝膠程序的反應液製備超疏水薄膜之可行性。二步驟溶膠-凝膠程序即是將單體與適量水先在酸性環境下行第一步驟反應後，再加入水與鹼行第二步驟的反應，藉此可製備出具有粗糙表面的薄膜，之後再以TMCS改質薄材表面。本研究探討反應液的凝膠時間(tG)、起始時間(tS)與第一步驟水添加量與矽氧烷之比例(Ra)、酸添加量、第二步驟水添加量與矽氧烷之比例(Rb)、鹼添加量以及溶劑種類的關係。同時也探討反應液隨時間之變化與接觸角及表面結構的關係。　　結果發現，反應液的tG與tS會隨著Ra、酸添加量、Rb以及鹼添加量的增加而下降，且溶液塗佈後所得膜層的表面結構會因成分添加比例不同而不同。若在反應前期即可得到穩定的粗糙結構，膜層則會有較高的接觸角。當TEOS : EtOH : Ra : HCl : Rb = 1 : 3.9 : 0.5 : 3.36x10-4 : 3且NH4OH/HCl為11.3時，可得表面為顆粒狀且接觸角為151°的膜層。另外，若將碳鏈較長的醇類加入凝膠時間短的配方，可藉以拉長凝膠時間以便容易製備出接觸角高的粗糙表面。

關鍵字

四乙氧基矽烷(TEOS) ；超疏水；二步驟溶膠-凝膠程序

並列摘要

Preparation of superhydrophobic tetraethoxylsilane(TEOS)-based silica surfaces by a two-step sol-gel process has been developed. The coating solution was prepared by adding water and acid into TEOS and reacted firstly, then adding ammonia and water into the above solution and reacted again. The roughness surface with hydroxyl groups was obtained by coating this solution onto the glass. Then the hydroxyl groups on the roughness surface were terminated by trimethylchlorosilane(TMCS) to produce a hydrophobic surface. 　　The effect of synthesis parameters, H2O/TEOS (Ra), amount of HCl, and types of solvent of the first step, H2O/TEOS (Rb) and NH4OH/HCl of the second step on the gelation time (tG) and onset time (tS¬¬) of the coating solution were studied. The influence of reaction time of the second step on structure and contact angle of films were also investigated. 　　The results showed that tG and tS¬¬ of coating solution were decreased with increasing Ra, amount of HCl, Rb and NH4OH/HCl. Superhydrophobic surface was obtained when the contact angle of the surface kept a constant value during the early stage of the coating solution. The silica films with contact angle 151° was obtained when preparation conditions TEOS:EtOH:Ra:HCl:Rb:NH4OH were 1:3.9:0.5:3.36x10-4:3:3.78x10-3. On the other hand, in order to obtain silica films with higher contact angle easily, various alcohol with long carbon chain were added into coating solution to increase tG and tS.

並列關鍵字

two-step sol-gel process ； Tetraethoxysilane ； superhydrophobic

參考文獻

1. Barthlott, W. and C. Neinhuis, "Purity of the sacred lotus, or escape from contamination in biological surfaces", Planta, 202(1), p.1-8, 1997

3. Collinson, M.M., "Sol-gel strategies for the preparation of selective materials for chemical analysis", Critical Reviews in Analytical Chemistry, 29(4), p.289-311, 1999

5. Brinker, C.J., "Hrdrolysis and condensation of silicates:effect on structure", non-crystalline solids, 100, p.31-50, 1988

6. Hegde, N.D., H. Hirashima, and A.V. Rao, "Two step sol-gel processing of TEOS based hydrophobic silica aerogels using trimethylethoxysilane as a co-precursor", Journal of Porous Materials, 14(2), p.165-171, 2007

7. Rao, A.V., et al., "Synthesis of flexible silica aerogels using methyltrimethoxysilane (MTMS) precursor", Journal of Colloid and Interface Science, 300(1), p.279-285, 2006

國際替代計量

以二步驟溶膠-凝膠法製備超疏水薄膜

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