Opportunities in Nanowire Production through Impure Aluminum Oxide Templates

Open Access
Author:
Moxim, Stephen John
Area of Honors:
Engineering Science
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Dr. Richard C. Bell, Thesis Supervisor
  • Dr. Reginald Hamilton, Honors Advisor
Keywords:
  • Nanowire
  • Aluminum Anodization
  • Al 1050
  • Aluminum Oxide
  • Nanomesh
Abstract:
It has been shown that nanowires and microwires produced via electrodeposition into aluminum oxide templates have numerous applications including catalysis, magnetorheological fluids, and a host of other uses. The templates have been traditionally made by anodizing high purity aluminum (>99.99% pure). In this process, a current is passed through an aluminum plate in an acid bath, which generates the aluminum oxide pores. The pore diameter and channel depth depend on such factors as current density, voltage, acid composition, temperature of the anodizing solution, and purity of the aluminum substrate. In order to reduce the cost of wire production, the anodization behavior of the aluminum alloy Al-1050 was examined at a range of anodizing voltages and phosphoric acid concentrations. Pore diameters and channel depths were measured using a scanning electron microscope. The results were compared to similar data found in the literature for the anodization of high purity aluminum. Overall, average pore diameters and channel depths were found to be similar to those reported for high purity aluminum, but with more variability. Many samples also showed promising features that may lead to the creation of other nanostructures such as banks of interconnected wires. In addition, AC electrodeposition must be used to deposit wires directly into high-purity aluminum templates without further processing. This process is hard to control, time-consuming, and expensive. This study shows that aluminum oxide templates created from the less pure alloys permits the use of DC electrodeposition, an easy and inexpensive method of wire deposition.