| 摘要: | 第一部份-表面潤濕性質的切換
智能潤濕性表面(smart surface)，又稱作為潤濕性可切換表面(Switchable surface)近年來吸引了許多的關注，透過調控外在環境刺激能控制表面對於水性及非水性液滴潤濕性質的轉換能力，讓其在多種領域的應用上具備很大的潛力。在本研究中我們藉由一種簡單快速且有效的方式於含有氫氧基團的基材上製備可置換性表面，透過含氟界面活性劑溶液潤洗材料表面，使表面化學組成改變趨向疏水和疏油的潤濕性質，然而其潤濕性質能透過CTAB水溶液的潤洗輕易的達到可逆行為，這種快速且簡易轉換潤濕性質的方法主要是經由轉酯反應(esterification)改質材料表面組成影響其潤濕性質。因為考慮到表面的形態和表面氫氧基團數量為進行轉酯反應和表面潤濕性質的主要因素，我們也嘗試以增加表面粗糙度以及氧化的方式，促使潤濕性可切換表面轉換的能力上升，將提升可轉換性表面的潤濕性質於超親水性/超親油性(CA~0°)和超疏水性(CA~156°)/接近超疏油性(CA~132°)之間來回轉換至少20次，並且對於水性和非水性液滴都具備一樣的效果。且此方法幾乎適用於所有類型的材料，例如金屬、陶瓷和高分子。
第二部份-水凝膠表面的完全潤濕行為
超親水材料應用在近幾十年來一直是業界所著重的領域，可以用於抗霧、抗反射、防生物沾黏以及用於作為輸送管線內壁材料，可降低流體摩擦減少能量之損耗，因此這種極端潤濕特性表面的研究近年來得到了廣泛的關注，成為材料科學領域的一個熱點。然而大多數超親水材料價格不斐且製備過程較為繁複，所以較超疏水表面來說，超親水表面的研究相對稀少。
於本研究中，我們以瓊脂凝膠(agar gel)的潤濕性質作為我們的研究目標，
瓊脂凝膠大部份為水組成，因此我們認為其作為物質表面材料能提升潤濕性質表現，但由於水凝膠不比一般固體材料擁有較強的機械性質，於實際應用端存在許多的限制，當我們增加瓊脂含量以提升瓊脂凝膠本身機械性質，卻發現瓊脂凝膠表面因瓊脂分子的取向力(orientation)而趨於疏水。而後我們嘗試在瓊脂凝膠添加界面活性劑以改善其表面潤濕性質，發現陰離子型界面活性劑能與凝膠中瓊脂分子產生作用，使得瓊脂凝膠表面呈完全潤濕性質(total wetting)，此外因為只添加些許的界面活性劑，所以不影響瓊脂凝膠本身的機械性質。此將界面活性劑摻入瓊脂凝膠中，所製得之超親水材料具有良好潤濕性質及機械強度，希望將來能應用於各領域之中增加效益。
;Part I – Smart surface with switchable wettability
Nowadays, switchable surface has drawn increasing of attentions for its myriad applications. Which wettability for both aqueous and non-aqueous drops can response to environmental stimuli. Reversible control of the surface properties has been achieved by various methods. In our case, we develop a facile and effective method to achieve the wettability transition on hydroxyl surface at ambient temperature. A fluoro-surfactant solution rinse acts as a stimulus to obtain a hydrophobic and oleophobic surface. Then, CTAB solution rinse can simply lead to the reversal of the surface wettability. The reversible behavior of switchable surface is ascribed to the esterification between the fluoro-surfactant and the hydroxyl surface of materials, such as metal, ceramics, and polymer. In order to enhance the ability of wettability switching, we conduct a series of experiment for surface modification, including roughening and oxidation for improving the esterification. As a result, it shows tremendous wettability changed from superhydrophilicity to superhydrophobicity.
Thus, this switchable surface can be employed to fabricate intelligent devices for controlling mobility and sensing.
Part II – Total wetting behavior on hydrogel surfaces
Extreme wetting behavior have been investigated in a variety of studies in recent decade. Superhydrophilic surface with low water contact angle on it, when a water droplet hen a water droplet contacts the superhydrophilic surfaces, water can spread over them completely. This type of surface is potentially applied to industrial application, such as antifogging、antifouling and droplet transportation. However, the fabrication of superhydrophilic surfaces is complicated and high cost. In this work, we manufacture a superhydrophilic surface with agar gel, which is consist mainly of water. Furthermore, we introduce the anionic surfactant in agar gel, and the wettability on the agar gel surface will be modified effectively, it can improve the wetting behavior on agar gel by the hydrophobic interaction between surfactants and agar molecules. Nevertheless, the mechanical properties of agar gel will not be degraded. This approach provides us an effective method to improve the wetting properties on high agar content agar gel surface. Therefore we can fabricate a superhydrophilic surface with outstanding mechanical and wetting properties by a simple method. |
