The impact of the polar core size and external organic media composition on micelle-micelle interactions: The effect on gold nanoparticle synthesis

Abstract

We report the effect of the molar ratio parameter W0(W0= [water]/[surfactant]) and the external organic media composition on benzyl-n-hexadecyldimethylammonium chloride (BHDC) reverse micelle (RM) interactions, the key step to nanoparticle synthesis using RMs as nanoreactors. The results show a better interaction between BHDC RM droplets when the external media contain toluene:hexane blends instead of pure toluene. This organic solvent mixture enhances the material exchange between droplets and more well defined and smaller gold nanoparticles were obtained at the two W0studied (3 and 6). On the other hand, BHDC RMs created in pure toluene give a stiffer environment with poor droplet-droplet interaction, and the Cl-counterions affect the growth of the particles, leading to different morphologies and sub-nanometer gold species production. These results are very promising for many applications. This work shows how each RM system is a unique and tunable nanoreactor.