Poly(alkyl/arylphosphazene)-Metal Nanoparticle Composites

Abstract

Nanoparticles of gold were prepared by reduction of Au(III) with a reducing agent in the presence of poly(methylphenylphosphazene), [Me(Ph)PN]n, (PMPP), an alcohol derivative (PMPP-OH), a graft copolymer poly(methylphenylphosphazene)-graft-polystyrene, PMPP-g-PS, and a blend of the two graft components. The process involved no phase transfer reagents because the polymers successfully moved the salts from the aqueous to the organic phase. The metal nanoparticles were characterized by UV–Visible spectroscopy and transmission electron microscopy (TEM). When stabilized by these phosphazene polymers, the average size of gold nanoparticles was between 3 and 5 nm. The PMPP-OH nanocomposites were stable in toluene at room temperature for several days, and showed no change on heating in the absence of solvent at 100 °C. In the graft copolymer and the blend, TEM imaging shows that the nanoparticles of gold were located exclusively in the phosphazene domains. An improved synthesis of the parent polymer, PMPP, used to make these and many other derivatives is described.