Preparation and catalytic activity of gold nanoparticles using well-defined thermosensitive polymers

Gold nanoparticles of 1-3 nm with a narrow size distribution were prepared using thermosensitive block or star-shaped polymers with oxyethylene side chains as a template. The thermosensitive polymers, prepared by living cationic polymerization in the presence of an added base, interacted weakly with auric ions in water. The interaction was likely between the auric ions and the oxygen atoms in the pendant of the polymers. The reduction of the ions using NaBH4 gave particles with less than 3 nm in diameter. These polymer-stabilized gold nanoparticles catalyzed aerobic alcohol oxidation in water at room temperature. More importantly, no particles flocculated during and/or after the reaction.