X-ray studies of polymer/gold nanocomposites

We demonstrate that x-ray reflection standing wave fluorescence spectroscop y is a highly sensitive technique for the determination of the distribution of metal nanoparticles inside polymer thin films. We investigate both the depth profile and the in-plane spatial correlation of gold nanoparticles in an asymmetric polystyrene-b-poly(2-vinylpyridine) block copolymer film. Th ese copolymer films self-assemble into alternating, nanometer-sized domains that are, upon annealing, selectively decorated by thermally evaporated me tal nanoparticles to form metal/polymer composites. (C) 1999 American Insti tute of Physics. [S0021-8979(99)02706-1].