Anti-Microbial Nanoparticles Composed of a Magnetic Core and Covered with Photocatalytic TiO2

Physical Sciences Inc. (PSI) proposes to utilize reverse micelles as constrained nanoreactors for controllably fabricating magnetically extractable, anti-microbial nanoparticles. A 20 nm diameter nanoparticle composed of a magnetite core surrounded by a titanium dioxide (anatase phase) shell will be the target of this Phase I. Critical to the success of this effort is the ability to control the micelle geometry and to minimize the processing temperature necessary for crystallization of the anatase layer. PSI intends to demonstrate the ability to control the diameter of the micelle's aqueous core, forming a cage-like structure, limiting the formation of the coating to a thin, uniform, conformal layer. After the coating layer is applied, temperatures in excess of 400 C are normally required to obtain the desired crystalline form and further densify the layer. These high temperatures can lead to defects in the structure through inter-diffusion, undesirable phase changes, and the generation of electron/hole recombination centers; potentially leading to both inefficient photoactivity and poor magnetic performance. In Phase I, PSI expects to demonstrate, using a simple metal salt, the formation of the anatase phase at temperatures as low as 150 C.