【摘要】 为验证氧气析出对PAA孔道产生和发展的作用,深入探讨PAA的形成机理,本文分别研究了在真空下和常压下,铝在磷酸溶液中的阳极氧化过程,用SEM表征了不同气压下PAA孔道的微观结构。在低气压下制备PAA膜,因为氧气析出速度快,所以同样条件下得到的PAA的孔道比常压下的孔径大、孔壁薄。结果表明,"酸性溶解腐蚀孔洞"只发生在氧化膜的表层,而表层下方是规则的"氧气析出孔道";PAA孔道的生成和发展是内部氧气析出孔道和酸性溶解腐蚀孔洞贯通的过程,但起决定作用的是"氧气气泡模具效应"。更多还原

【Abstract】 The influence of oxygen release rate on the pore growth and microstructures of the porous anodic alumina(PAA)membrane was experimentally studied.The microstructures of the PAA membrane,prepared by phosphoric acid etching at different pressures,were characterized with scanning electron microscopy(SEM).The results show that the pressure considerably affects the microstructures of the PAA membrane.The pore size formed at 104 Pa is bigger with thinner walls than those grown at 105 Pa,under the same etching conditions,possibly because of the higher oxygen release rate at a lower pressure.We suggest that two mechanisms account for the pore growth:acidic etching on alumina surface combined with perforation of the well-ordered oxygen release pores inside the membrane.更多还原