Wednesday, January 28, 2009

Growth of PS beads on gold nanocrystals

Ohnuma et al. (Xia group at Washington U. St. Louis) presents a beautiful way of dressing up gold nanocrystals with polystyrene (PS) polymer. They start the polymerization and then introduce the gold (50 nm) nanocrystals at a magic time, 2 minutes after the initiation. 30 minutes had 50 % success for gold embedding and 0 minutes had multiple gold cores in PS particles (in all cases PS size was around 300 nm with somewhat round shape). I wonder if plasmonic resonance played a role in the growth of the PS. As they promised to publish a mechanistic paper, we'll have to wait.


  1. It is an interesting result. Actually, polystyrene is hydrophobic and the surface of gold is hydrophilic. I thought the oxidant might play a role in the conjunction of both species. Akira needs to prove why polystyrene does this undefined behavior. Lets see next paper.

  2. What is emazing is that the Au NPs are on the surface of PS particles, instead of the usual case that Au NPs sit in the center. Any explanation from this paper?