Electrospinning, or electrostatic spinning, is a process capable of producing polymer and composite fibers. The fibers are notable for their small diameter, large surface area to volume ratio, and small but continuous pore size. The fundamental idea of electrospinning is introducing a high electrostatic field to a small droplet of viscous liquid causing it to form a jet accelerated towards the oppositely charged collector, where a solid state mesoporous membrane of nanofibers is deposited.

My project focuses on the possibility of utilizing electrospun silica in the remediation of heavy metal contamination. Prior to my involvement, work was done to observe the interaction of electrospun silica and uranyl acetate solutions over time. Depending on solution parameters, both fibers and spheres can be produced utilizing the electrospinning process. It was observed that electrospun nanofibers did not present any interaction with the uranyl solution. Electrospun spheres participated in a time controlled reaction, first sequestering the uranyl ions from solution and then releasing them. Preliminary data obtained suggests this process could be used to remove heavy metal contaminates from unwanted areas and then deposit them elsewhere in a sponge-like manner. This research could also provide insight into the reaction pathways for U(VI) with silicates in soil or materials used in environmental remediation.

The first stage of this project involves determining how to control the morphology and chemistry of electrospun silicate so that the conditions conducive to the production of silica spheres will be confirmed. Extensive studies will be conducted to observe time-dependent reactions of electrospun silica (which may also contain silicate) with uranyl acetate solution. The structure and chemistry of both the silica/silicate and the uranyl complexes formed will be studied through the use of scanning electron microscopy, FTIR, and Raman spectroscopy.

SEM of uranyl acetate reacted with spheres(a) and fibers(b)