You are here:
Sustainable environmental nanotechnology using nanoparticle surface modification.
Citation:
Phenrat, T., S. Karzy, B. VERONESI, P. Alvarez, AND G. Lowry. Sustainable environmental nanotechnology using nanoparticle surface modification. Presented at American Chemical Society, New Orleans, LA, April 08 - 12, 2008.
Impact/Purpose:
Support criteria of MYP
Description:
Reactive nanomaterials used for environmental remediation require surface modification to make them mobile in the subsurface. Nanomaterials released into the environment inadvertently without an engineered surface coating will acquire one (e.g. adsorption of natural organic matter). Thus, the chemistry of the surface coating control a nanoparticles interactions with mineral surfaces, organic matter, and living organisms, and hence control its overall fate and potential for exposure and toxicity. This study investigates the effects of polyelectrolyte surface coatings on the mobility of nano-sized Fe0 (NZVI) particles in porous media, and its potential toxicity to microorganisms and its potential neurotoxicity in vitro. NZVI is surface modified with polyaspartate (MW=2000 to 3000 g/mol), characterized in terms of size, adsorbed layer mass and conformation, surface charge, and aggregation. The transport of bare and modified particles is determined in saturated sand columns, the cytotoxicity of bare and surface-modified NZVI to B. subtilis and E. coli is measured in batch systems, and the potential neurotoxicity is assayed in vitro using a number of toxicity end points. In all cases, the presence of a surface coating significantly increased the mobility of the nanomaterials in sand columns, thereby increasing the potential for exposure. However, the surface coatings significantly decreased the toxicity of the NZVI compared to unmodified NZVI, suggesting that surface modification can be used to enhance functionality while decreasing the potential for mammalian and ecotoxicity. Such data are useful for the safe utilization of nanoparticles for ground water remediation. Disclaimer: This document has been reviewed by the NHEERL but does not necessarily reflect the views of the Agency.