Production of Colorful Aluminum Keepsakes and Gas Sensing Smart Materials: Anodizing, Dyeing, and Etching Small Aluminum Parts on a Budget

Abstract

This work describes an effective, low cost method to anodize small aluminum objects. The use of a PVC spacer between the anode and cathode significantly reduces the size of the electrochemical cell and electrolyte required for its operation. Students will explore the physical and chemical properties of aluminum and anodized aluminum. They will have the opportunity to apply the techniques they have learned during the design and production of a personalized aluminum name tag. Immersion of the anodized aluminum samples in aqueous pH indicators bromocresol purple or thymol blue produces solid-state gas sensors that are used to detect HCl(g) or NH3(g). The modules described in this work are acceptable for introductory chemistry classes both at the high school and undergraduate levels.