介電質放電及電弧式常壓噴射電漿掃描製成於氧化還原石墨烯-聚苯胺-殼聚醣超級電容之應用

Abstract

本研究主要是使用氮氣電弧式常壓噴射電漿，及氬氣介電質放電噴射電漿對碳纖維布進行改質，並將還原氧化石墨烯-聚苯胺-殼聚醣奈米複合材料，網印在處理過之碳纖維布上，作為軟性超級電容電極。氮氣電弧式常壓電漿處理時的基板溫度峰值在約500°C，而氬氣介電質放電噴射電漿處理時基板溫度約在40°C。在碳纖維布經電漿改質前後方面，由電子顯微鏡 (SEM) 與原子力顯微鏡 (AFM) 的觀察，發現處理過後之碳纖維布表面皆變粗糙，由水接觸角 (WCA) 發現改質後的碳纖維布皆呈現親水性，但兩者電漿處理後的碳纖維布在空氣中貯存則有相當不同的反應。氮氣電弧式常壓電漿所處理之碳布親水性可以維持20週以上，但氬氣介電質放電噴射電漿處理之碳布親水性在12小時後開始往疏水轉變。由X-射線繞射儀 (XRD) 與拉曼光譜儀 (Raman spectrometer) 發現處理後之碳纖維布皆無結構上之明顯改變，由電子微探儀 (EPMA) 與X-射線光電子能譜儀 (XPS)，發現處理過後之碳纖維布皆有氧摻雜的作用，而氮氣電弧式電漿則有強烈之氮摻雜反應。在超級電容應用方面，發現兩種常壓電漿皆有效地提升超級電容之電容值，並以電化學阻抗頻譜分析 (EIS) 結果可得知，改質後的碳纖維布皆具有較小之電荷轉移電阻，且具有較高之電雙層電容與法拉第電容。從此研究證實了電漿之高反應性粒子具有碳纖維布表面改質功能，增加親水官能基於碳纖維，增加碳布的親水性，進而提升超級電容的性能。溫度則具有協同的碳布改質效果，因此電弧式常壓噴射電漿 (氣體溫度較高) 所處理之碳布在空氣中儲存能維持較長時間之親水性。

This study investigates the carbon cloth modified by nitrogen arc atmospheric pressure plasma jet (APPJ) and Ar dielectric barrier discharge jet (DBD jet). The carbon cloth is then used as the collecting electrode for reduced graphene oxide (rGO)-polyaniline (PANI)-chitosan (CS) nanocomposite flexible supercapacitor. The peak temperature of substrate under nitrogen arc APPJ processing is ~500°C whereas that under Ar DBD jet is ~40°C. The roughness of carbon fibers increases upon plasma treatment, as evidenced by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Water contact angle measurements indicate the improvement in the hydrophilicity of carbon cloth after nitrogen arc APPJ and Ar DBD jet treatments. However, the hydrophilicity to hydrophobicity recovering rate is very different with these two types of plasma treatment. Upon storage in normal environment, carbon cloth treated by nitrogen arc APPJ can maintain the hydrophilicity for more than 20 weeks, however, that treated by Ar DBD jet starts to recover to hydrophobicity after 12 h. X-ray diffraction (XRD) and the Raman spectrometry analyses show no significant structural alternation upon plasma treatment. X-ray photoelectron spectroscopy (XPS) and electron probe microanalyzer (EPMA) indicates the introduction of oxygen- functional groups to the carbon fibers of the carbon cloth by both nitrogen arc APPJ and Ar DBD jet treatments. Moreover, nitrogen arc APPJ treatment also introduce nitrogen doping on carbon fibers. Both nitrogen arc APPJ and Ar DBD jet treatments on carbon cloth can improve the capacitance value of the supercapacitor. Electrochemical impedance spectroscopy (EIS) show lower charge transfer resistance upon both plasma treatments. Our results suggest that reactive plasma species can modify the surface properties of carbon cloth by introduction oxygen-containing functional groups and increase the surface roughness. Temperature has additional effect on surface modification of carbon fibers such that carbon cloth treated by nitrogen arc APPJ can maintain the hydrophilicity for a much longer period.