水+正辛烷+界面活性劑C4E1三成份系統之相行為研究與利用溶膠凝膠法製備隨時間演變之薄膜

Abstract

本研究分為兩部份，第一部份針對水+正辛烷+非離子型界面活性劑C4E1之三成份系統探討其相行為，C4E1 為醇醚類化合物，為CH3(CH2)3(OCH2CH2)OH之縮寫。此系統具有三液相共存區的存在，利用水與正辛烷的重量比為1:1 並改變C4E1 的重量分率，觀察系統於不同溫度達平衡時的液相數目，將結果繪製成魚形相圖。接著利用氣相層析儀，對系統進行液-液相平衡量測，並將結果繪製成三角相圖，根據實驗結果，系統隨溫度上升，可觀察到從兩液相轉變為三液相再轉變成兩液相的相行為。此外，我們利用NRTL 及UNIQUAC 模型對實驗數據進行迴歸及理論計算，發現NRTL 模型可有效地描述水+正辛烷+C4E1 三成分系統的相行為。 第二部分，利用溶膠凝膠法將methyl-tri(2-hydroxyethyl)orthosilicate 當作前驅物與pluronic 界面活性劑合成出中孔洞的二氧化矽材料，並利用旋轉塗佈法將溶膠鍍玻璃基材上，經過鍛燒程序後，利用觀察表面型態了解系統中形貌隨著時間的改變，再利用矽烷類自組裝單分子降低表面能之後，利用前進角及後退角的量測探討表面型態對表面親疏水性的影響，發現最高角度可達155°，為超疏水表面。

The first part of this study, we investigate the phase behavior of the ternary water + n-octane + nonionic surfactant C4E1 system. C4E1 is the abbreviation of CH3(CH2)3(OCH2CH2)OH. There were three-liquid-phase-coexisting regions in the system. Experiments of fish-shaped phase diagrams for the system were performed at constant water/n-octane weight ratio (1/1) with varying weight fraction of surfactant,and the number of liquid phases was recorded at different temperature. There was a transition for the number of liquid phases from two to three, and then to two along with increasing temperature. Liquid–liquid equilibrium measurements were performed by gas chromatography. For the two-liquid-phase-coexisting regions, there was more C4E1 in the lower phase at the lower temperature; however, there was more C4E1 in the upper phase at the higher temperature. The experimental liquid-liquid equilibrium data were successfully correlated with the NRTL model. In the second part of this study, we use a novel precursor methyl-tri(2-hydroxyethyl)orthosilicate, incorporated with a pluronic surfactant, to synthesize mesoporous silica material via sol-gel process in aqueous solution.Evolution of the morphology of the sol-gel system has been monitored by spin-coating the sol-gel solution onto the glass substrate to “freeze” the morphology in the sol-gel process. The nano- and micro-domain formation and growth in the sol-gel process are discussed. These substrates were further calcinated and modified by silaned self-assembled monolayer to lower their surface energy. The effect of morphology on the surface hydrophobicity will be also discussed.