Influence of poly(vinyl alcohol)/poly(N-vinyl-2-pyrrolidone) polymer matrix composition on the bonding environment and characteristics of Ag nanoparticles produced by gamma irradiation

A series of silver nanoparticles (AgNPs)-poly(vinyl alcohol)/poly(N-vinyl-2-pyrrolidone) (PVA/PVP) hydrogel nanocomposites were synthesized by gamma irradiation to examine the matrix's impact on properties of Ag nanocrystals important for strain engineering in functional materials. SEM analysis and the swelling studies revealed nanocomposite morphology and fluid transport properties. UV-Vis absorption characterization of AgNPs has enabled an understanding of the cluster size effects. The gel content indicated inter-crosslinking of the two components of the polymer matrix, especially for equivalent (1:1) PVA/PVP ratio, affecting the investigated AgNPs structural parameters. The lattice parameters and the interface stress, analyzed using XRD, have the lowest negative magnitude from the bulk lattice constant for the PVA/PVP (2:1) and (1:1) ratio. The lowest values of the lattice strain and dislocation density, as mutually dependent parameters, are obtained in AgNPs embedded in a PVA/PVP (2:1) and (1:1) matrix. The XPS and FTIR data show a positive shift of the O1s and a redshift of the CO - Ag vibration band indicating charge transfer to the vacant orbital of Ag nanocrystals. The N atoms of the pyrrolidine ring are not directly involved in the electronic interactions, but over the p-pi conjugation with carbonyl O. In addition, the tested Ag-(PVA/PVP) hydrogel nanocomposites showed significant potential as a broad-spectrum antibacterial material.