High thermal stability of block copolymer-capped Au and Cu nanoparticles.

Producing solution-based metal nanoparticles that do not agglomerate at elevated temperatures remains challenging. We show that thermally stable Au and Cu nanoparticles can be prepared using polystyrene-poly(4-vinylpyridine) diblock copolymers as capping agents. These materials remain stable when their solutions are subjected to prolonged heating up to 160 °C for more than 48 h. These conditions are sufficient for applications in most wet chemical processes and reactions.