Preparation of Corona-Embedded CdS Nanoparticles

In this paper, two novel methods of preparing CdS nanoparticles within the corona of block copolymer micelles are presented. (1) Corona-embedded CdS nanoparticles were prepared by dropping core-embedded CdS nanoparticles into water with a low pH value. The location change of the CdS nanoparticles was accompanied by a structural change of the micelles, from compound micelles to single micelles. The CdS nanoparticles are randomly distributed in the corona of the single micelles. The size of the nanoparticles increases slightly after the transition. (2) Corona-embedded CdS nanoparticles can also be prepared using the “in situ” reaction of S 2 - with Cd 2+ ion clusters in the corona of the micelles. The single micelles with Cd 2+ ion clusters in the corona were prepared by dropping poly(styrene- block -2-vinylpyridine)−Cd 2+ compound micelles into water with a low pH value. The size of the corona-embedded CdS nanoparticles is affected by starting pH value in water, complex concentration, and S 2 - source.