Kinetics of dissolution of silver nanoparticles inside triton N-42 reversed micelles

Our spectrophotometric study of the kinetics of dissolution of silver nanoparticles by nitric acid inside inverted micelles of Triton N-42 (a nonionic surfactant) verified the universal character of the mechanism for this type of process, which includes the interaction of surface metal atoms with an oxidizer in two routes: either with (autocatalysis) or without newly formed ionic species of the oxidized metal. Effective rate constants for both routes are independent of the value of solubilization capacity (Vs/Vo is the ratio of the volume of the dispersed aqueous phase to the volume of the micellar solution); the solubilization capacity is useful to control the micelle and particle sizes: k1 = 0.018±0.003, 0.010±0.003, and 0.012±0.003 s−1 and k2 = 2.5±0.8, 1.5±1.1, and 1.4±0.4 L/(mol s) for 100 Vs/Vo = 1, 2, and 3%, respectively.