Growth Kinetics of Gold Nanoparticles in Reverse Micelles

A.P. Herrera, E. Vicuña, C. Rinaldi, M.E. Castro, L. Sola, R. Irizarry and J.G. Briano
University of Puerto Rico, US

Keywords: micelles, growth kinetics, gold nanoparticles

Abstract:
Gold nanoparticles were formed from the reduction of gold (III) in reverse micelles and monitored with a stopped flow analyzer. The gold and the reducing agent micelles were formed in isooctane and AOT (as surfactant). The overall reduction of gold (III) occurred in less than 20 [ms]. The growth kinetics was followed from measurements of the time-dependent wavelength absorption spectra, and by analyzing the evolution of the dipole resonance. The dielectric constant of the medium was calculated, and the growth results were modeled with Mies scattering theory. The modeling assumes the mean size of the particles to be characterized by the position of the plasmon. Excellent agreement between theory and experiment are found at the peak maximum and long wavelength tail, for particle sizes up to 90 [nm]. The dependence of the gold dielectric constant on particle size and the effect of multi-pole interactions were taken into consideration

Nanotech 2004 Conference Technical Program Abstract