A Raman-Based Imaging Method for Characterizing the Molecular Adsorption and Spatial Distribution of Silver Nanoparticles on Hydrated Mineral Surfaces.

Although minerals are known to affect the environmental fate and transformation of heavy-metal ions, little is known about their interaction with the heavily exploited silver nanoparticles (AgNPs). Proposed here is a combination of hitherto under-utilized micro-Raman-based mapping and chemometric methods for imaging the distribution of AgNPs on various mineral surfaces and their molecular interaction mechanisms. The feasibility of the Raman-based imaging method was tested on two macro- and microsized mineral models, muscovite [KAl(AlSiO)(OH)] and corundum (α-AlO), under key environmental conditions (ionic strength and pH).