ORGANIZATION OF POLYMER-CAPPED PLATINUM COLLOIDAL PARTICLES AT THE AIR-WATER-INTERFACE

This communication discusses the formation of thin films of platinum c olloidal particles by organization at the air-water interface. The pla tinum clusters were prepared by sodium borohydride reduction of aqueou s chloroplatinic acid with the nanoparticles being capped with a polym er, poly(vinylpyrrolidone) (PVP). After separation from the aqueous me dium, the capped clusters were dispersed on the surface of water, usin g the hydrophobic component of the capping agent to organize the clust ers at the air-water interface. Pressure-area measurements showed a re gion of rather low compressibility, characteristic of a reasonably com pact, ordered phase of the colloidal particles. The Langmuir monolayer of the platinum clusters was transferred to suitable substrates and a nalyzed using transmission electron microscopy, quartz crystal microgr avimetry and X-ray photoemission spectroscopy. An organized monolayer of platinum clusters was observed indicating that the air-water interf ace may be used as a medium for obtaining nanoparticle films for devic e applications. (C) 1998 Elsevier Science S.A. All rights reserved.