臺灣大學: 化學工程學研究所邱文英; 陳立仁楊詠茹Yang, Yung-JihYung-JihYang2013-03-272018-06-282013-03-272018-06-282011http://ntur.lib.ntu.edu.tw//handle/246246/252218本篇研究內容分為兩部分：其一為提供一個簡單又便宜的方法來製備超疏水表面，並探討液滴在具結構的親╱疏水表面的濕潤行為，其二為探討液滴在 2 μm 親疏水相間條紋的濕潤行為。 液滴於複合及具結構表面的濕潤行為被廣泛地運用在工業上，並在科學研究中被廣泛地探討，而降低表面能及增加表面粗糙度為製備超疏水性表面的方法。本研究先用軟壓印技術壓印出具結構的高分子表面，包括各尺寸的柱狀突起結構，並具有不同的間距，再經由浸泡自組裝單分子膜溶液進行表面改質。經過表面改質後的具相同結構的各高分子膜，其接觸角皆相同，並且和 Cassie 模型以及 Wenzel 模型也有良好的吻合。本研究亦將未改良的具結構高分子親水膜的接觸角做一併的討論，然而此部分的接觸角無法和Cassie 模型以及 Wenzel 模型有良好的吻合。 此外，本研究提供一個簡單的能量計算模型藉由 Matlab 的運算，估算出液滴於線寬兩微米的親疏水相間的條狀圖紋表面所擁有的平衡接觸角；並使用數值分析軟體 Surface Evolver 模擬液滴在此表面上的濕潤現象，探討前進角、後退角、平衡接觸角及液滴外觀上的改變。研究中可以發現藉由 Matlab 計算所得到的平衡觸角 (77.76°) 和 Cassie Equation 所計算出來的接觸角數值 (78°) 完全吻合。 而雖然此數值與由 Surface Evolver 中所得到的結果有些微的差距，但兩者整體的趨勢還是相符合的 － 在小體積的系統下，角度會震盪；而在大體積的系統下，角度會趨近於一個定值。在本研究的系統中，前進角恆為一定值 (110°)，而後退角則會受體積的影響而改變 － 在小體積的系統下，角度會震盪；而在大體積的系統下，角度會落在70°~80°的區間內。本研究亦指出液滴的接觸線 (Contact Line) 略為橢圓形，並非唯一完美的圓形。再者，本研究對接觸角轉變區域的厚度 (Thickness of transition region) 也做了探討，由疏水角度轉變為親水角度的無因次厚度為 0.22，而由親水角度轉變為疏水角度的無因次厚度為 0.02-0.0027。There are two sections in our studies. First part is a simple and cheap method for fabrication of superhydrophobic surface and the wetting behaviors on structured hydrophilic or hydrophobic surfaces are also studied. The other part is the study of wetting behavior on 2 μm striped heterogeneous surface. Wetting behavior plays an important role in various industries, and has been studied for a long while. Lower the surface energy and enhance the surface roughness are the method to prepare superhydrophobic surface. We are able to combine and modify a soft-embossing technique and surface modification of a self-assembled monolayer to establish a standard operation procedure for manufacturing superhydrophobic surfaces. Two issues are addressed in this part of study. First, the water contact angles of surfaces without modification are discrepant with the Wenzel and Cassie models. Second, the different polymer surfaces with modification can change their characteristics from hydrophilicity to hydrophobicity. Further, different polymer surfaces have the same contact angle only if they have the same structure before modification. And the results are quite consistent with Wenzel and Cassie models. Besides, we examine contact angle of liquid droplet on 2 μm striped surface by the Matlab modeling and also determine equilibrium contact angle (ECA), advancing contact angle (ACA) and receding contact angle (RCA) from free energy curve obtained by the Surface Evolver. The ECA (78°) from the Matlab modeling is totally consistent with the Cassie model, but is quite different from the results (83°~85°) shown in the Surface Evolver. However, the tendencies of ECAs from both methods are the same – oscillation with small liquid and approaching a constant with larger liquid. In our system, ACA is always a constant (110°) but RCA is volume-dependent. RCA oscillates at first, and finally falls into a certain narrow region (70°~80°). Our result also indicates that the contact line of liquid drop inclines to be a slightly ellipse-like shape, not a perfect circle-like shape. Further, we make a discussion about the thickness of contact angle transition region. The dimensionless thickness from hydrophobic to hydrophilic surface is almost 0.22, and the dimensionless thickness from hydrophilic to hydrophobic surface decreases from 0.02 to 0.0027 as increasing liquid volume.2789617 bytesapplication/pdfen-US超疏水表面接觸角自聚性單分子膜複合表面數值方法superhydrophobic surfacecontact angleSAMcomposite surfaceSurface Evolverthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/252218/1/ntu-100-R98524021-1.pdf