Surface modification of SiO2 nanoparticles with PDMAEMA brushes and Ag nanoparticles as antifungal coatings using electron beam assisted synthesis

Abstract

A model functional, stable and dispersible silver nanoparticles (AgNPs) immobilized on polymeric brushes grafted silica nanoparticle is proposed as antimicrobial additive for coating applications. The aim of this work is to modify silica nanoparticles (SiO2NPs) with poly 2-(dimethyl amino) ethyl methacrylate (PDMAEMA) brushes for template synthesis and immobilization of AgNPs using electron beam assisted grafting and reduction reactions. The PDMAEMA moieties were grafted onto vinyltrimethoxysilane (VTMS) modified SiO2NPs using pre-irradiation and peroxidation grafting approaches. Several grafting parameters, i.e., pre-irradiation doses, DMAEMA monomer concentrations, reaction times and temperatures, were studied to optimize degree of grafting (DG). AgNPs were constructed on the SiO2NPs through the grafted PDMAEMA brushes as polymer shell template. AgNPs were successfully created on SiO2NPs-VTMS-PDMAEMA by electron-induced reduction reaction. DG of the PDMAEMA on SiO2NPs-VTMS was confirmed by gravimetric measurement, FTIR, TGA, TEM, FE-SEM. The nanostructure information and AgNPs immobilization were revealed by UV–Vis, TEM, SEM-EDX and XRD. The optimized grafting degree to obtain desirable appearance was 190%. The AgNPs (6 ± 2 nm) on SiO2NPs-VTMS-PDMAEMA exhibited the characteristic UV-vis absorbance of spherical Ag nanoarchitecture around 418 nm. The AgNPs immobilized SiO2NPs-VTMS-PDMAEMA efficiently inhibited the growth of fungi, i.e., Aspergillus niger and Syncephalatrum racemosum found on building materials.