Synthesis of colloidal gold nanoparticles of different morphologies in the presence of triblock polymer micelles

The Au nanoparticles have been synthesized in the presence of micellar solutions of fixed concentration (i.e. 1.4 x 10(-3) mol dm(-3)) of each poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), triblock polymers (TBP), such as P103, P84, P123, and F127. The nanoparticles have also been synthesized in the presence of mixed micellar solutions of binary TBP mixtures such as P103+ P84 and P103 + P123. In the previous case, "raspberry type" Au nanoparticle-TBP aggregates have been observed in which nanoparticles of 2-3 nm have been uniformly distributed throughout the TBP micelle. On the other hand, in the latter case, apart from such aggregates, prominent ordered morphologies of nanoparticles such as rod, sphere, triangle, and hexagonal have also been observed with much larger dimensions. This has been attributed to the nucleation process occurring in the mixed micelles rather than in the micelles of single TBP components.