Influence Of Anodizing Voltage And Electrolyte On Interpore Distance Of Anodic Aluminum Oxide Template

In this work, we research the relationship between the interpore of anodic aluminumoxide （AAO） template and the influencing factors of electrolyte, temperature and oxidationvoltage etc. was researched and summarized in this paper. It was pointed out that theinterpore was influenced mostly by electrolyte type and oxidation voltage, and least by theelectrolyte concentration and oxidation temperature. The interpore of AAO templateincreases with the oxidation voltage increases. By adjusting the electrolyte and oxidationvoltage, a desired interpore of template can be acquired. To acquire a large interporetemplate can use electrolyte of phosphoric acid under a comparatively higher oxidationvoltage. To acquire template with interpore less than10nmcan use sulfate electrolyte under acomparatively lower oxidation voltage，but the oxidation reaction can’t work with smallvoltage, with the help of higher pulse voltage the problem will be solved. We analyzed theoxidation process ofporous anodic alumina and simulated the distribution of electric field inhole of oxide film with the finite element software. We discussed the main impact of anodicoxidation voltage in forming process of the film hole. Through the section of electric fieldintensity vector diagram and potential profile, the research reveals that in the process ofoxidation, the anions in the electrolyte and the cations on the metal surface are how totransport, which directions they migrate and the process of oxidation film hole’s growth withthe help of electric field force. The results show that the anodic oxidation voltage is the keyfactor in control oxide film growth. The growth of film hole and the shape of the growthprocess arelinked closelywith the distributionofelectric field in the oxidation film.We got some conclusions fromthe study：（1） The growth of the film hole and its shape during growth are closely associated withthe distribution of the electric field in the oxide film. With oxidation voltage applied，theanions and cations thread the oxide layer and driven reaction further. The unions reach themetal/oxide interface with the electrostatic force. These anions sustain new oxide generatedto keep a balance state. Under a certain number of electric field intensity in the cell, the number of anions and cations through the oxide layer is greater than the part of the weakelectric field intensity. The speed which the anions and cations reach the metal/oxideinterface and formthe new oxides is also larger. The diameter ofthe oxide film holes and thedistance ofthe holes willchange along with the change ofthe anodic oxidation voltage.（2） From series of summaries, we realized that the interpore of AAO template hasintimate connections to the electrolyte ingredient, electrolyte concentration, temperature andoxidation voltage, but the influence of electrolyte concentration and oxidation temperaturecan be ignored.（3） According to the different requirements of the interpore of template, neededtemplate can be fabricated byadjusting the electrolyte and oxidation voltage.（4） In order to acquire small interpore of template （the interpore <20nm） could usesulphuric acid as electrolyte with low （<6V） oxidation voltage, but the oxidation reactioncan’t work with small voltage; with the help of higher pulse voltage the problem will besolved. Alternatively, use H2SO4and Al2（SO4）3as mixed electrolyte.（5） The anodic oxidation voltages affect migration routes of the anions and cationswithin the cells, and affect the electric field distribution in cellular internal. There is aquantitative relationship among the interpore (D_int)，the anodic oxidation voltages U andporosityP.