UV photoactivation for size and shape controlled synthesis and coalescence of gold nanoparticles in micelles

Formation of stable gold nano-particles of different size and shape has been reported via UV photoactivation of HAuCl4 in variable concentrations of TX-100. It has been shown that smaller particles of gold preferentially dissolved by cyanide at a faster rate in air in comparison to that for the larger particles because of higher mobility and possibly because of lower redox potentials of the smaller particles. It is observed that smaller gold nanoparticles preferentially coalesce together at higher temperature in micelles. Temperature induced changes in the shape of the micelle provide the required template/capping condition for linear growth of gold nanoparticles.