Tuned optical properties of in-situ synthesized m-nitroaniline doped Ag/PVA nano-composites.

Meta-nitroaniline (m-NA) doped silver/poly(vinylalcohol) (Ag/PVA) nanocomposites are prepared via in-situ reduction of silver salt by employing hydrazine hydrate (HH) in order to study the effect of the NLO active m-NA on the optical properties of nanoparticles of silver in the colloidal as well as self supported film form. Reduction of silver salt in aqueous alcoholic PVA with HH is done first followed by doping of the reaction mixture with m-NA. The UV-Visible absorption spectra show peak at about 400 nm for Ag nanoparticles due to surface plasmon resonance phenomenon, which gets blue shifted with the change in m-NA concentration. The Second Harmonic Generation (SHG) studies show improvement in intensity with increasing m-NA concentration up to a saturation point (approximately 2.52 wt% with respect to PVA). Further increase in m-NA concentration leads to decrease in SHG intensity. The solutions and the films are characterized by photoluminescence (PL), FTIR spectroscopy, XRD, SEM, TEM, and thermal analysis. m-NA doped composites showed better PL efficiency. SEM of the nanocomposite film shows uniform distribution of particles within the film. The particle size as shown by TEM is found to be less than 10 nm.