Preparation and characterization of hydrophilic and antibacterial silver decorated silica‐grafted‐poly(vinylpyrrolidone) (Ag‐SiO2‐PVP) nanoparticles for polymeric nanocomposites

Hydrophilic antibacterial silver decorated silica‐grafted‐poly(vinylpyrrolidone) (Ag‐SiO2‐PVP) nanoparticles were successfully synthesized in multiple steps. In this regard, silanization of the silica nanoparticles was performed with different concentrations of vinyltrimethoxysilane (VTS) to generate vinyl groups onto the nanoparticles surface. Obtained results showed that by increasing the VTS concentration the amount of vinyl groups on the surface of the silica nanoparticles increased while nanoparticles agglomeration did not occur. Then, poly(vinylpyrrolidone) PVP brushes were grafted onto the silanized silica nanoparticles (SiO2‐VTS) via grafting‐through polymerization method to obtain PVP‐grafted silica nanoparticles (SiO2‐PVP). Fourier transform infrared spectroscopy, thermal gravimetric analysis, and dynamic light scattering confirmed the successful generation of the vinyl groups and PVP brushes onto the silica nanoparticles. Finally, Ag‐SiO2‐PVP nanoparticles were prepared by synthesizing silver nanoparticles onto the SiO2‐PVP nanoparticles to render them antibacterial. Energy dispersive X‐ray spectroscopy showed that highest grafting of silver nanoparticles onto the SiO2‐PVP nanoparticles was obtained for the nanoparticles with highest content of vinyl groups. X‐ray photoelectron spectroscopy was used to identify the elements and their chemical structure for the synthesized nanoparticles. Plate colony counting method was applied to assess the antibacterial effects of the Ag‐SiO2‐PVP nanoparticles which revealed outstanding bactericidal properties of them. Poly(vinylpyrrolidone)(PVP) polymer brushes and fine silver NPs were grafted chemically onto the surface of the silica nanoparticles to synthesize highly hydrophilic and antibacterial Ag‐SiO2‐PVP nanoparticles. Several analyses were performed to confirm the successful synthesis of the Ag‐SiO2‐PVP nanoparticles. Moreover, an effective way was used to prove the antibacterial properties of the prepared nanoparticles against different types of bacteria. Synthesized nanoparticles can be used in various polymeric matrixes to obtain polymeric nanocomposites with hydrophilic and antibacterial properties for various applications.