Nanosecond laser-irradiation assisted the improvement of structural, optical and thermal properties of polyvinyl pyrrolidone/carboxymethyl cellulose blend filled with gold nanoparticles

Gold nanoparticles (Au NPs) supported within the polymeric matrix of polyvinyl pyrrolidone/carboxymethyl cellulose (PVP/CMC) were successfully prepared through the novel in situ method. These (PVP/CMC)/Au hybrid nanocomposites were exposed to nanosecond laser-irradiation with different powers. These nanocomposite samples were investigated before and after the irradiation process through various techniques such as X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet/visible spectroscopy (UV/Vis), transmission electron microscope (TEM), differential thermal analysis (DTA) and thermogravimetric analysis (TGA) techniques. The XRD analysis depicted the amorphous nature for PVP/CMC blend and showed the characterizing peaks of Au NPs for the nanocomposite spectrum, where the intensity of these peaks was largely decreased after irradiation process. The FT-IR spectra showed that the blend components were miscible via showing the functional groups of two polymers that were interacted through the formation of a hydrogen bond and the FT-IR spectra of nanocomposite and irradiated samples were affected. Also, the mechanism of interactions between blend and Au NPs was proposed. The UV/Vis. spectra depicted the formation of Au NPs within the PVP/CMC matrix through showing the surface plasmon resonance peak (SPR) of Au NPs at 546 nm. The UV/Vis. the absorbance of this peak was increased and its position was red-shifted after the irradiation process implying the formation of smaller NPs and the narrow size distribution as confirmed by TEM micrographs. The thermal properties for prepared samples were determined through DTA and TGA techniques.