ion of ILs into an oxalic acid aqueous solution commonly used for the fabrication of APA has been investigated. Two different ILs have been used for the first time as additives in this anodization process. By adding one of them, namely 1-butyl-3-methylimidazolium tetrafluoborate, in an approximately 1:1 molar ratio with the solution acid, and properly tuning the current density, we could obtain a growth rate of APA of 1.1 μm/min. This growth rate is comparable to the value normally obtained in the industrially applied HA conditions, but has been obtained in MA conditions in our case. Therefore, our process should make it possible to obtain thick APA layers in comparatively short times (order of few hours) and with ordered pore arrays also on the outer surface, after two-step anodization in the appropriateV range. The high-anodization current in itself does not guarantee fast APA growth, as demonstrated when the other IL was used as the EL additive. Therefore, a better understanding of the chemical mechanisms underlying the observed increase in growth rate has to be pursued, and is currently the subject of further research activity in our group. However, the presently reported preliminary results hold promise for the development of a technologically viable procedure for the fast growth of APA. In this application perspective, the possible use of ILs in characterization of the porous film and in its subsequent processing has also been explored. As a result, the selected IL has been demonstrated to be useful also as a pore wall protection medium during pore opening of APA, a process step that is often taken when passing membranes are fabricated out of the supported porous surfaces.
The authors would like to thank Mr. Romeo Losso for providing the original idea of using ionic liquids in the preparation of anodic porous alumina and for the recommendations, thereafter, and Mr. Claudio Larosa for technical support and useful discussions on the topic.
- Masuda H, Fukuda K: Science. 1995, 268: 1466. ; COI number [1:CAS:528:DyaK2MXmtFKktbc%3D]; Bibcode number [1995Sci...268.1466M] 10.1126/science.268.5216.1466View ArticleGoogle Scholar
- Ono S, Saito M, Asoh H: Electrochim. Acta. 2005, 51: 827. COI number [1:CAS:528:DC%2BD2MXhtFGhtrvJ] 10.1016/j.electacta.2005.05.058View ArticleGoogle Scholar
- Redon R, Vazquez-Olmos A, Mata-Zamora ME, Ordonez-Medrano A, Rivera-Torres F, Saniger JM: Rev. Adv. Mater. Sci.. 2006, 11: 79. Google Scholar
- Stura E, Bruzzese D, Valerio F, Grasso V, Perlo P, Nicolini C: Biosens. Bioel.. 2007, 23: 655. COI number [1:CAS:528:DC%2BD2sXhtlWksb%2FO] 10.1016/j.bios.2007.07.011View ArticleGoogle Scholar
- Thompson GE: Thin Solid Films. 1997, 297: 192. ; COI number [1:CAS:528:DyaK2sXktVGit7k%3D]; Bibcode number [1997TSF...297..192T] 10.1016/S0040-6090(96)09440-0View ArticleGoogle Scholar
- Liao CL, Chu CW, Fung KZ, Leu IC: J. Alloy Compd.. 2007, 441: L1. COI number [1:CAS:528:DC%2BD2sXmsFCitbY%3D] 10.1016/j.jallcom.2006.09.084View ArticleGoogle Scholar
- Li Y, Ling ZY, Chen SS, Wang JC: Nanotechnology. 2008, 19: 225604. Bibcode number [2008Nanot..19v5604L] Bibcode number [2008Nanot..19v5604L] 10.1088/0957-4484/19/22/225604View ArticleGoogle Scholar
- Chen W, Wu J-S, Xia X-H: ACS Nano. 2008, 2: 959. COI number [1:CAS:528:DC%2BD1cXksl2gurc%3D] 10.1021/nn700389jView ArticleGoogle Scholar
- Yang P, An M, Su C, Wang F: Electrochim. Acta. 2008, 54: 763. COI number [1:CAS:528:DC%2BD1cXht1GrurrJ] 10.1016/j.electacta.2008.06.064View ArticleGoogle Scholar
- Sui YC, Saniger JM: Mater. Lett.. 2001, 48: 127. COI number [1:CAS:528:DC%2BD3MXisVWhtb8%3D] 10.1016/S0167-577X(00)00292-5View ArticleGoogle Scholar
- Zhou J-H, He J-P, Zhao G-W, Zhang C-X, Zhao J-S, Hu H-P: Trans. Nonferrous Met. Soc. China. 2007, 17: 82. COI number [1:CAS:528:DC%2BD2sXksFKrtLo%3D] 10.1016/S1003-6326(07)60052-1View ArticleGoogle Scholar
- Tsuya N, Tokushima T, Shiraki M, Wakui Y, Saito Y, Nakamura H, Hayano S, Furugori A, Tanaka M: IEEE Trans. Magn.. 1986, 22: 1140. Bibcode number [1986ITM....22.1140T] Bibcode number [1986ITM....22.1140T] 10.1109/TMA