Greener and other approaches to synthesize Fe and Pd nanoparticles in functionalized membranes and hydrogel

Nano-scale materials have applications in diverse fields, such as catalysis, electronics, and medical science. In the pollution remediation field Fe and Fe/Pd nanoparticles (NPs) are being used to detoxify chlorinated organics. The use of unsupported NPs often leads to aggregation and loss to environment. Our approach is based on direct synthesis of iron-based NPs in membranes and temperature responsive hydrogel supports by using "greener" approach. In our current work, we investigated a simple and fast method of Fe and Fe/Pd NPs synthesis in polyacrylic acid functionalized polyvinylidene fluoride (PAA/PVDF) membranes, using "green" reducing agents (green tea extract and epicatechin), as an alternative to the commonly used reducing agent, sodium borohydride. In addition, we have synthesized reactive Fe/Pd NPs in hydrogel, P(NIPAAm-AA (poly- N-isopropylacrylamide-acrylic acid). Both membrane and hydrogel immobilized NPs have been applied to successful dechlorination of TCE and various PCBs. For example, the surface area normalized reaction rates for TCE ranged between 0.008 to 0.04 L/m2h with Fe/Pd systems. Membrane polymer support and hydrogel had insignificant loss of NPs to environment.