Colloids and composite materials Au/PVP and Ag/PVP generated by laser ablation in polymeric liquid environment

Abstract

Pulsed laser ablation of Silver and Gold targets, immersed in a polymeric solution of Polyvinylpyrrolidone (PVP), is used to generate colloids and composite metal-polymer. Solutions of PVP in deionized water at different concentrations are employed. Two PVP number average molecular weights were considered, 10000 g/mol and 55000 g/mol. The high purity targets are irradiated between 20 min and\linebreak 40 min with the third harmonic (THG) ($\lambda = 335$ nm) of a Nd:YAG laser operating at a rate of 10 Hz with pulses of 8 ns. Optical spectroscopy in UV and vis regions, Scanning Electron Microscopy (SEM), High Resolution Scanning Electron Microscopy (HR-SEM) and X-Ray are used to identify and determine the shape and size of the produced particles. Very stable sub-micrometric spherical particles for Au/PVP y Ag/PVP samples are obtained with diameters of 0.72 $\mu$m y 0.40 $\mu$m, respectively. The preparation of colloids is performed in one step and no surfactant or dispersing agent is used in this process.