Optical properties of gold colloids formed in inverse micelles

We discuss the formation of gold metal colloids in a variety of surfactant/solvent systems. Static and dynamic light scattering, small angle x-ray and neutron scattering, TEM analysis, and UV-visible absorbance are used to characterize the kinetics of formation and final colloid stability. These gold colloids exhibit a dramatic blueshift and broadening of the plasmon resonance with decreasing colloid size. Several types of reduction method are discussed and differences between micelle (water-free) or microemulsions as reaction media are compared. Use of inverse micelles allows smaller clusters to be formed with greater long-term stability