摘要
传统理论无法诠释多孔阳极氧化铝(Porous Anodic Alumina,PAA)表面条纹和孔道的形成机制。为了诠释表面条纹和PAA孔道各自的形成过程,结合阳极氧化过程的电压-时间曲线和SEM照片,仔细分析了传统“场致助溶理论”和氧化物生长溶解平衡理论的局限性,并实验验证了PAA孔道氧化物的生长速率为113 nm/min,该速率远大于60℃磷酸溶液对氧化铝的溶解速率5.8 nm/min。首次实验证明了在PAA孔道形成过程中不存在氧化物生长和溶解的平衡。并用离子电流和电子电流理论诠释了Al阳极氧化过程的动力学,离子电流导致阻挡层氧化物生长,电子电流导致氧化物生长效率降低并产生氧气气泡。气泡模具效应导致了PAA圆柱形孔道和半球形底部的形成,表面条纹是电解液的化学溶解和污染层下氧气气泡的体积膨胀所致,而非自组织过程所致。本文对广泛应用的TiO_(2)、ZrO_(2)纳米管的结构调控是非常有益的。
Traditional theories are incapable of explaining the formation mechanism of surface stripes and channels in porous anodic alumina(PAA).In order to elucidate the formation process of surface stripes and PAA channels,the limitations of the traditional“field-assisted dissolution theory”and the equilibrium theory of oxide growth and dissolution were meticulously analyzed by integrating the voltage-time curve and SEM images of the anodic oxidation process.The growth rate of PAA pore oxides is experimentally verified to be 113 nm/min,which is significantly greater than the dissolution rate of alumina in a 60℃phosphoric acid solution of 5.8 nm/min.The experiment demonstrate that there is no equilibrium between oxide growth and dissolution during the formation of PAA channels.The kinetics of Al anodizing is explained by the theory of ionic current and electronic current.Ionic current leads to the growth of barrier oxide,while electronic current results in the decrease of oxide growth efficiency and the generation of oxygen bubbles.The oxygen bubble mold effect gives rise to the formation of cylindrical channels and hemispherical bottoms of PAA.The surface stripes are caused by the chemical dissolution of the electrolyte and the volume expansion of oxygen bubbles under the anion contaminated layer,rather than by self-organizing process.This paper is beneficial to the structural regulation of widely used TiO_(2)and ZrO_(2)nanotubes.
作者
金俊
李鹏泽
丁磊
余行康
刘霖
JIN Jun;LI Pengze;DING Lei;YU Xingkang;LIU Lin(Nantong Jianghai Capacitor Co.,Ltd.,Nantong 226361,Jiangsu Province,China;School of Chemistry and Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;College of Environment and Chemical Engineering,Jiangsu Ocean University,Lianyungang 222005,Jiangsu Province,China)
出处
《电子元件与材料》
CAS
北大核心
2024年第8期957-965,共9页
Electronic Components And Materials
基金
国家自然科学基金(61171043)
国家自然科学基金(51577093)。
