Functionalized TiO2 nanoparticles for use for in situ anion immobilization.

Anatase particles (40-60 nm) were coated with an organosilane monolayer terminated with an ethylenediamine (EDA) ligand. These functionalized nanoparticles (FNPs) were then treated with an aqueous solution of Cu(II) to create a cationic Cu-EDA complex bound to the nanoparticle surface. Cu(II) and EDA ligand incorporation were confirmed by X-ray photoelectron spectroscopy (XPS) analysis. The Cu(EDA)2 FNP was then studied for its binding affinity for pertechnetate anion from a Hanford groundwater matrix. The Cu(EDA)2 FNP was also evaluated for its injectability into a porous medium for possible application as a subsurface semipermeable reactive barrier. Injection was readily accomplished, and resulted in a highly uniform distribution of the FNP sorbent in the test column.