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多孔型阳极氧化铝(PAA)和多孔阳极氧化钛纳米管因其在诸多领域的广泛应用而备受关注.然而这类多孔阳极氧化物中纳米孔道的形成机理至今还不清楚,阳极氧化过程中电流-时间曲线与多孔形貌之间的关系至今无法解释.本文从致密型阳极氧化铝(CAA)的击穿机理入手,详细对比了CAA和PAA形成过程的区别与内在联系,从两种氧化膜电流-时间曲线(或电压-时间曲线)的分界点这个全新视角入手,找出了阳极氧化过程中氧化物形成效率下降的本质原因是电子电流的产生和氧气的析出.在CAA中球形孔洞的证据充分说明初期的规则孔洞是氧气气泡形成的.铝在混合电解液中阳极氧化的结果表明,一旦氧气析出停止,孔道生长就停止并被致密型的氧化物覆盖,一种新型的复合型氧化膜由此而得.最终结果表明:在PAA的形成过程中,适当的电子电流是氧气析出和孔洞形成的保证,适当的离子电流是氧化物形成和孔壁生长的保证.
Porous anodic aluminum oxide (PAA) and porous anodic titanium oxide nanotubes (CNTs) have attracted much attention due to their wide application in many fields. However, the formation mechanism of nanoporous channels in such porous anodic oxide is still unclear. In the anodic oxidation process The relationship between current-time curve and porous morphology can not be explained until now.This paper starts with the breakdown mechanism of dense anodic aluminum oxide (CAA), and compares the difference and internal relationship between CAA and PAA in detail. Starting from a brand new perspective of the demarcation point of the membrane current-time curve (or voltage-time curve), it is found that the essential reason for the decrease of oxide formation efficiency during anodic oxidation is the generation of electron current and the precipitation of oxygen. In CAA, The evidence shows that the initial regular pores were formed by oxygen bubbles.The results of anodic oxidation of aluminum in the mixed electrolyte showed that once oxygen evolution stopped, pore growth ceased and was covered by dense oxide, a new type of composite The resulting oxide film.The final results show that: in the formation of PAA, the appropriate electron current is oxygen deposition and hole formation guarantee, the appropriate Sub-current is to ensure that oxide formation and growth of the cell walls.