Cost-effective technique to fabricate a tubular through-hole anodic aluminum oxide membrane using one-step anodization

Abstract

In order to reduce the time required to prepare a tubular through-hole anodic aluminum oxide (AAO) membrane, this study improved the manufacturing processes using one-step anodization. AAO membranes were first prepared by using 6063 commercial aluminum alloy tubes using an external anodizing method. The manufacturing processes for a tubular through-hole AAO membrane include: annealing, physically wet grinding, buff wheel polishing, ultrasonic cleaning, one-step anodizing, aluminum substrate removing, and barrier layer alumina (BLA) etching. The influence of chemical etching time on the nanostructure of AAO membranes was observed by a Field Emission Scanning Electron Microscope (FE-SEM). The results of the fabrication of a tubular through-hole AAO membrane showed that increasing the chemical etching time of the BLA etching process could result in an enhanced nanotube pore size and a reduced AAO membrane thickness, and excessive chemical etching time would collapse the nanotube structure. The tubular through-hole AAO membrane obtained was straight nanotubes with a thickness of 48 μm and an average bottom pore size of 109 nm.