Nanocomposite hydrogen-bonded multilayer ultrathin films by simultaneous sexithiophene and Au nanoparticle formation

Terthiophene-functionalized poly(4-vinylpyridine) (PVP3T) was incorporated successfully as a reductant to form Au nanoparticles within hydrogen-bonded complexed multilayer thin films. By employing polymer pendant terthiophene moieties, this eliminated the need for an external reducing agent. The redox reaction with HAuCl4 yielded Au nanoparticles simultaneously with the formation of electrooptically active sexithiophene units. The nanocomposite films were characterized by TEM, XPS, UV-vis, photoluminescence, FT-IR, and ellipsometry measurements. The TEM images confirm unequivocally the formation of well-dispersed nanoparticles within the multilayer structure with a range of size distributions dependent on the preparation conditions. Interestingly, we observed the growth of dendritic nanostructures within the PVP3T/poly(acrylic acid) multilayers with modifications to the preparation procedure. On the basis of these results, this method yields a unique approach for the fabrication of nanocomposite multilayer heterostructures comprised of metallic nanoparticles and conjugated oligomers with interesting nanostructural and spectroscopic properties.