Published online by Cambridge University Press: 01 March 2012
Dry-coated nanosilver is a promising material for bio-applications. Its inert and non-porous nanothin SiO2 coating preserves the plasmonic properties of the nanosilver and cures its toxicity by (1) preventing direct cell to silver contact and (2) blocking the release of toxic silver ions. However, fully hermetic coatings have, to date, not been produced. During the coating process, a certain number of core particles are either coated only partially, or escape the coating process entirely. Here, a systematic parametric study was undertaken in order to optimize an aerosol reactor for the synthesis and dry-coating of nanosilver. The reactor was optimized with respect to coating injection height, jet number, mixing flow rate. By synthesizing xAg/SiO2 composite particles, small silver sizes (9-11 nm) with relatively high Ag ion release were obtained. This enabled the quantitative evaluation of the coatings by Ag ion release measurements.