Nanosecond Pulsed Laser Ablation in Liquids as New Route for Preparing Polyvinyl Carbazole/Silver Nanoparticles Composite: Spectroscopic and Thermal Studies

Abstract

Silver nanoparticles (AgNPs) were synthesized by pulsed laser ablation in liquids technique (PLAL) using the laser parameter: irradiation time, power source and wavelength of nanosecond laser pulses. Nanocomposite films of poly (n-vinyl carbazole) (PVK) doped with synthesized AgNPs were prepared using casting method. Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) had been used to investigate the Spectroscopic and thermal characterizations of the prepared PVK/Ag nanocomposites samples. The IR spectra illustrated that there is a combination between PVK matrix and silver nanoparticles. Also, itillustrated that the band at 3052 cm⁻¹ of PVK was shifted towards higher wavenumber by about (15–25) cm⁻¹ at the time of irradiation 40 min, power 570 mW and wavelength 532 nm. SEM detected the existence of Ag nanoparticles that leading to changes in morphology of the surface. The thermodynamic parameters: activation energy ${{\text{E}}^{\text{*}}}$, entropy$\Delta {{\text{S}}^{\text{*}}}$, enthalpy $\Delta {{\text{H}}^{\text{*}}}$ and Gibbs free energy $\Delta {{\text{G}}^{\text{*}}}$ that obtained from TG data in second decomposition step according to Coat’s–Redfern model were helpful in assigning the bond strength, ordering and thermal stability of the investigated samples. It was found the joint effect of both elevated temperature and coordination of Ag nanoparticles in PVK matrix were responsible for weakening and strengthening of the composite system.