电聚合表面改性对电容器用高纯铝箔侵蚀行为的影响

Effect of surface modification by electropolymerization on the etching behavior of high purity aluminum foils used for capacitors

在铝箔表面电聚合制备导电聚合物薄膜,进行表面改性,并在硫酸-盐酸-硝酸钠电解质体系中采用直流方式进行电蚀,研究电聚合表面改性对铝箔电蚀的行为的缓蚀效果及缓蚀机制。研究结果表明:聚合物薄膜通过傅里叶红外检测为酸掺杂态。导电聚合物薄膜覆盖在铝箔表面使其维持高电位,腐蚀介质透过聚合物膜层,使铝发生溶解,在膜层处生成气相,导电聚合物膜层起到阴极作用,促进了铝箔腐蚀形成孔径大小相似的隧道孔,提高了发孔密度和隧道孔长度,气相破坏膜层且阴极薄膜发生氧化还原反应,对铝箔表面过蚀行为起到缓蚀作用。对比聚苯胺薄膜和聚吡咯薄膜对铝箔直流电蚀行为影响,通过扫面电镜图(SEM)和金相断面(OM)分析,表明聚苯胺薄膜的缓蚀效果更为明显,有效提高了表面发孔密度,改善了铝箔表面的过蚀现象,改善了隧道的孔形貌。

The investigation is conducted on the effect of electropolymerization surface modification of aluminum foil on the etching process of high purity aluminum foil in H2 SO4- HC1-NaNO3 under DC current. It is proved that the polymer film is in the acid doped state af- ter the Fourier infrared detection. The conductive polymer film covered on the foil surface keeps the film at high potential, etching medium makes aluminum dissolved through the poly- mer film, and gas doping is formed. Conducting polymer film acts as a cathode, accelerating film etching to form tunnels with similar pore size, and raising the density and length of tun- nels. The film is destroyed by gas doping and the redox reaction takes place on the cathode film ,which inhabit the over etching behavior on the film surface. Comparative analysis with SEM and OM shows the etching inhabitation effect of polyaniline film is better than that of polypyrrole film. The polyaniline film greatly increases the tunnel density, reduces over etch- ing, and improves the tunnel morphology.