Nd:YAG nanosecond laser induced growth of Au nanoparticles within CMC/PVA matrix: Multifunctional nanocomposites with tunable optical and electrical properties

Gold nanoparticles (Au NPs) were successfully prepared by the Morus nigra (M. nigra) leaf extract. Polymer nanocomposite film based on host polymer matrix of carboxymethyl cellulose/polyvinyl alcohol (30/70 wt%) blend and Au NPs (0.36 wt%) had been prepared by casting of aqueous solutions. This nanocomposite film was subjected to nanosecond laser irradiation with different time intervals. The FT-IR spectra implied the miscibility of the CMC/PVA matrix through the existence of the functional groups of the virgin polymers which have been interacted by the hydrogen bond production and the intensity of these spectra was significantly increased after the Au NPs addition and irradiation process. The UV/Vis. spectra obtained the existence of gold nanoparticles in the composite film through appearance its SPR peak that had blue shift correlated by an increase in the absorbance intensity at high exposure time intervals. The TEM micrographs indicated the spherical shape of Au NPs and its size was reduced because of the addition and laser-irradiation processes. The electrical and dielectric spectra of these prepared samples were investigated. The exposure time of laser irradiation dependent electrical conductivity and dielectric permittivity was existed and the effect of interfacial polarization in these spectra was explained. The investigated properties authenticate multi-functionality of these biodegradable polymer nanocomposite samples such as optical band gap tuner and electrical conductivity and dielectric permittivity controllable nano-dielectrics for the next generation flexible electronic and optoelectronic devices.