Nanocomposite Langmuir-Blodgett films based on crown derivatized platinum nanoparticles: Synthesis, characterization, and electrical properties

This paper deals with the crown derivatization of 4-mercaptoaniline functionalized platinum formation and the use of the resulting nanoparticles to build up controlled Langmuir and Langmuir-Blodgett films. It is shown that the high density of amine functions at the surface of platinum nanoparticles functionalized by 4-mercaptoaniline offers the possibility of over grafting with various molecules giving rise to different rate of crown derivatization ranging from 19% to 45%. The derivatizations process of the organic coating has been characterized by infrared spectroscopy and thermo gravimetric analysis. The elaboration of Langmuir and Langmuir-Blodgett films containing different ratio of derivatized nanoparticles and fatty acid is reported and the thin films are characterized using X-ray photoelectron spectroscopy and small-angle X-ray scattering. A marked structural anisotropy due to the deposition process is revealed, that corresponds in some cases to a well-defined layered organisation. Modifications in electrical conductivity induced by crown derivatization are reported. These crown derivatized particles are currently studied towards the oxygen reduction reaction.