石墨烯塗層對鋁合金表面抗蝕性質之影響

Abstract

本篇論文分為兩部分，第一部分為鋁合金前處理對於石墨烯與鋁合金之間的附著性與抗蝕性影響，第二部分則為多層石墨烯之分散與噴塗對於鋁合金之抗蝕性分析。第一部分中我們以化學氣相沈積法製備單層石墨烯並轉印製鋁合金表面，並使用常見的酸洗液，如硫酸、硝酸、磷酸做鋁合金之酸洗，而後以接觸角儀測量不同液體與不同表面之接觸角，計算出表面能以分析石墨烯與鋁合金表面之附著度。實驗中以拉曼光譜儀分析石墨烯是否具有明顯之缺陷、以極化曲線測定單層石墨烯覆蓋於鋁合金後之抗蝕能力、以原子力顯微鏡分析不同表面處理所造成之鋁合金表面高低起伏，由上述實驗分析出硝酸前處理後鋁合金的表面最適合石墨烯附著。 第二部分我們使用購買之氧化石墨烯分散液，以硼氫化鈉做為還原劑，將氧化石墨烯還原後以高能超音波均質機還原之氧化石墨烯分散至無水酒精中，以噴塗方式將還原之氧化石墨烯噴塗至鋁合金表面，達到多層石墨烯的效果，並以極化曲線分析其抗蝕能力，以原子力顯微鏡觀察其表面形貌、以掃描式電子顯微鏡配以聚焦離子束切割，觀測噴塗之石墨稀薄膜厚度。由此方法有效解決化學氣相沈積法所製備之石墨烯無法大量、大面積合成的問題，以提高石墨烯作為抗蝕塗層之實際應用能力。

This study is divided into two prats. The first part presents an investigation into the effect of surface pretreatment on the electrochemical characteristics and corrosion behavior on graphene coated 6061 aluminum alloy (Al 6061). The corrosion properties of graphene coated 6061 aluminum alloy with different surface pretreatments were studied using electrochemical impedance spectroscopy (EIS), and polarization measurement. Surface morphologies of pretreated and coated samples were analyzed by atomic force microscopy (AFM). The integrity of graphene transferred from the growth Cu substrate was examined by Raman spectroscopy. We also investigated the adhesion between the graphene and Al 6061 by measuring the water and diiodomethane contact angle, and calculating the surface free energy of various pretreated samples. In the second part, solving the problem that chemical vapor deposition graphene can not be made and transferred in large area, we reduced graphene oxide by NaBH4 and spray it on the surface of 6061 aluminum. The corrosion properties of reduced graphene oxide film is analyzed by potentiodyanmic polarization, and the topography and thickness of reduced graphene oxide film is observed by AFM and scanning electron microscopy (SEM).