Silver nanoparticles (AgNPs) have been incorporated into a wide range of consumer products and there is significant potential for release of AgNPs. Once AgNPs enter the environment, the surface layer may be displaced or covered by naturally abundant macromolecules. The capping agents, by coordinating with surface atoms, can effectively block reactants from reaching surface sites and thus slow reaction rates. In this study, nanosphere lithography (NSL) method was used to fabricate uniform arrays of AgNPs immobilized on glass substrates. Polyethylene glycol (PEG) and bovine serum albumin (BSA) were used as capping agents. The dissolution experiments were conducted in an air-saturated phosphate buffer with 550 mM NaCl in the absence of aggregation. Tapping-mode atomic force microscope (AFM) was used as the primary technique by measuring the height of AgNPs. The dissolution rate for uncoated AgNPs is 1.69 nm/d. While the dissolution rate for BSA, PEG1000 and PEG5000 coated samples decrease to 0.39 nm/d, 0.20 nm/d and 0.14 nm/d, respectively. PEG coatings provide a steric barrier to the mass transfer of reactants to sites on the AgNPs surface and diminish dissolutions. On the other hand, interactions between BSA and AgNPs cause an acceleration of the dissolutions in the first several hours.

Controlled evaluation of surface coating effects on silver nanoparticle dissolution

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.