微波電漿沉積聚四氟乙烯奈米片狀結構超疏水及疏油薄膜之研究

本研究利用四氟甲烷(CF4)與八氟環丁烷(C4F8)混合氣體電漿進行表面鍍膜，提高基材之疏水及疏油特性，探討電漿進氣流量比、改質時間、基材擺放位置等參數對基材表面疏水及疏油性質的影響。並利用WCA、SEM、AFM、XPS、FTIR等儀器分析表面物理形態與化學組成之變化，搭配電漿放射光譜儀（OES）分析電漿中物種濃度的變化。研究以微波電漿對玻璃基材進行表面改質，研究中發現C4F8:CF4為7:43~12:38之進氣流量比的表面氟碳膜片狀結構為佳，改質後表面具有超疏水（~165°）及疏油 (~ 151°) 特性。由FTIR分析中可發現電漿沉積膜有大量之CF2鍵結，再經由SEM及AFM中發現在超疏水之表面會有片狀之結構且粗糙度約75 nm左右，因此推斷表面有超疏水及疏油現象是由於氟碳官能基的鍵結以及表面粗糙度的形成有關。在不同時間對氟碳膜表面之化學及物理特性進行探討，測得片狀膜形成於室溫下，前30秒以氣相成核以及表面蝕刻為主，片狀膜至3 min時最為密集且明顯，隨著時間增加奈米片狀結構越鬆散。最後，為了探討在不含氟之膜材表面粗糙度對接觸角之影響，本研究利用氫氣及乙烷電漿對經電漿沉積氟碳膜後再進行改質，結果發現改質後之膜材表面氟原子含量大幅降低，並保有部分表面粗糙度。改質後之膜面對水之接觸角變化取決於表面粗糙度變化與膜面氧碳比之變化，然而對於非極性液體之接觸角則呈現親油性，顯示疏油性質在本研究中，F受到膜材表面化學組成之影響遠大於表面物理形態，且氟元素為影響最大之因素。

關鍵字

四氟甲烷；八氟環丁烷；超疏水；疏油；微波電漿；奈米片狀膜

並列摘要

In this study, the deposited fluorocarbon films on glass substrate were fabricated by mixed-gas plasma of C4F8 and CF4. The characteristics of the deposited films were investigated through contact angle measurement, fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The analysis of plasmas concentration changing with optical emission spectrometer (OES) The results revealed that placement of substrates, mixed gas flow ratio (C4F8:CF4) could control the relative concentrations of free radicals and the resulting surface topography. FE-SEM and XPS analysis indicated that the films deposited at specific positions possess special nano-flakes structure, resulting in not only roughed but also hydrophobic surfaces. To further study correlation between surface roughness and water contact angle measurement, both Wenzel and Cassie-Baxter models were used. The roughness factor of super-hydrophobic film was about 1.38 and surface solid fraction was 0.026, resulting in a very low contact angle hysteresis. As revealed by XPS analysis, the super-hydrophobic wall-like film has a fluorine/carbon (F/C) ratio about 2.1, but of C4F8: CF4 ratio is between 7:43 to 12:38 the effect nano-flakes structure and contact angle are the best. The chemical and physical properties of the fluorocarbon film were investigated at different treatment times. The film formation was measured at room temperature, and the gas phase nucleation and surface etching were mainly effected at the beginning. As the CF2 increased, the plasma deposited nano-flakes structure in 3 minutes was the most dense and obvious.