Dispersion of Gold in Polycarbonate by Vapor-Induced Crystallization

Abstract

It has been demonstrated that dispersion of noble metal nanoparticles in an organic matrix can be achieved by crystallization of amorphous low-molecular-weight nylon-11 in a process called relaxative autodispersion. In the present paper we report the dispersion of Au by acetone vapor-induced crystallization of amorphous polycarbonate films. Crystallization kinetics were examined with infrared spectroscopy. Au dispersion was detected with X-ray photoelectron spectroscopy in conjunction with ion-beam depth profiling and cross-sectional transmission electron microscopy. While vapor sorption in films of some micrometers thickness occurs within minutes at room temperature, crystallization and Au dispersion take place on a time scale of hours. Crystallization gives rise to a strong enhancement of surface roughness measured by atomic force microscopy. The present approach of metal dispersion is not restricted to low-molecular-weight polymers. A model for the dispersion process is proposed.