Adsorbed triblock copolymers deliver reactive iron nanoparticles to the oil/water interface.

Reactive zero valent iron nanoparticles can degrade toxic nonaqueous phase liquids (NAPL) rapidly in contaminated groundwater to nontoxic products in situ, provided they can be delivered preferentially to the NAPL/water (oil/water) interface. This study demonstrates the ability of novel triblock copolymers to modify the nanoiron surface chemistry in a way that both promotes their colloidal stability in aqueous suspension and drives their adsorption to the oil/water interface. The ability of the copolymers to drive adsorption is demonstrated by the ability of copolymer-modified iron nanoparticles, but not the unmodified iron nanoparticles, to stabilize oil-in-water emulsions.