利用連續及脈衝模式之八氟環丁烷電容耦合電漿製備疏水表面之研究

Abstract

本研究利用電漿製程來製備超疏水表面，處理了濾紙、聚對苯二甲酸乙二酯(PET)、玻璃三種表面。首先利用氧氣電漿蝕刻濾紙表面來產生奈米尺度之粗糙度，並成功製備出含有微、奈米結構的階層式結構後，再利用氟碳電漿沉積低表面能的氟碳薄膜至階層式結構上，透過提升氧氣電漿之射頻功率或在低射頻功率下提升處理時間，皆能製備超疏水濾紙且表面非常滑，其水接觸角為170°、滑落角為0°；另外，實驗結果也顯示若沒有利用氧氣電漿蝕刻濾紙表面，僅利用氟碳電漿沉積氟碳薄膜於濾紙表面上，提升電漿處理時間，能製備出超疏水濾紙且表面非常黏，其水接觸角為155°、滑落角為90°，最後藉由掃描式電子顯微鏡(SEM)與傅立葉轉換紅外線光譜儀(FTIR)的分析來進一步確認濾紙表面之微結構以及表面之化學組成。 接著為PET表面改質，利用氬氣電漿蝕刻PET表面來產生奈米尺度之粗糙度，再利用氟碳電漿沉積低表面能的氟碳薄膜至奈米結構上，當提升氬氣電漿之射頻功率時，可以發現表面之水接觸角逐漸上升，且滑落角也逐漸下降，並藉由SEM來觀察PET表面微結構的變化。 最後本研究提出了三步驟電漿處理來製造超疏水玻璃表面，第一步利用氟碳電漿沉積足夠厚的氟碳薄膜於玻璃表面，第二步利用氬氣或氬氣/氧氣電漿蝕刻此氟碳薄膜來嘗試產生粗糙度，再於第三步利用氟碳電漿沉積一層較薄的氟碳薄膜來預防第二步蝕刻所造成的化學鍵結破壞，三步驟電漿處理後之水接觸角皆位於105~115°、滑落角位於40~60°，並藉由SEM的輔助分析，可推論第二步之電漿蝕刻未使得氟碳薄膜的表面產生粗糙度，反而是破壞了表面之化學鍵結。本研究也嘗試利用脈衝模式氟碳電漿來製備超疏水玻璃表面，先利用電漿光譜分析來計算沉積性自由基(CFx)之衰退速率常數，接著再分別調整了脈衝時間(on-time)、脈衝間隔時間(off-time)、射頻功率，其表面之水接觸角位於105~115°、滑落角位於40~60°，並藉由SEM來觀察氟碳薄膜表面微結構的變化。

This study utilizes plasma processing to fabricate superhydrophobic surfaces, focusing on three substrates: filter paper, polyethylene terephthalate(PET), and glass. Initially, oxygen plasma is used to generate nanoscale roughness on the filter paper surface, successfully creating hierarchical structures with micro- and nanostructures. Subsequently, a fluorocarbon plasma is used to deposit a low surface energy fluorocarbon film onto the hierarchical structures. By either increasing the RF power of the oxygen plasma or extending the treatment time at low RF power of the oxygen plasma, superhydrophobic filter paper with extremely slippery surfaces can be fabricated, exhibiting a water contact angle of 170° and a sliding angle of 0°. Additionally, the experimental results show that if the filter paper surface is not etched with oxygen plasma and only a fluorocarbon film is deposited using fluorocarbon plasma, extending the plasma treatment time can produce superhydrophobic filter paper with very sticky surfaces, exhibiting a water contact angle of 155° and a sliding angle of 90°. Finally, the surface structure and chemical composition of the filter paper surface are further confirmed through analysis using Scanning Electron Microscopy(SEM) and Fourier-Transform Infrared Spectroscopy(FTIR). Subsequently, for the surface modification of PET, argon plasma is used to create nanoscale roughness on the PET surface. And, a low surface energy fluorocarbon film is deposited onto the nanostructures using fluorocarbon plasma. Increasing the RF power of the argon plasma leads to a gradual increase in the water contact angle and a corresponding decrease in the sliding angle on the surface. Finally, changes in the surface structure of PET are observed by SEM analysis. Lastly, this study proposes a three-step plasma treatment to fabricate superhydrophobic glass surfaces. In the first step, a sufficiently thick fluorocarbon film is deposited onto the glass surface using fluorocarbon plasma. In the second step, argon or argon/oxygen plasma is used to attempt to create roughness on the fluorocarbon film. In the final step, a thinner fluorocarbon film is deposited using fluorocarbon plasma to prevent the chemical bond damage caused by the second step of etching. After the three-step plasma treatment, the water contact angles range from 105° to 115°, and the sliding angles range from 40° to 60°. By SEM analysis, we conclude that the second step of plasma etching does not create roughness on the surface of fluorocarbon film but rather damages the chemical bonds. This study also attempts to use pulsed mode fluorocarbon plasma to fabricate superhydrophobic glass surfaces. First, optical emission spectroscopy is used to calculate the decay time constant of the depositing radicals(CFx). Then, the on-time, off-time, and RF power are adjusted accordingly. The modified surfaces have water contact angles between 105° and 115°, and sliding angles between 40° and 60°. Finally, SEM images are used to observe the changes in the surface structure of fluorocarbon film.