Preparation of Composite Hydrogels with Silica Nanoparticles by Photoinitiated Polymerization Reaction

Abstract

In this study, (3-mercaptopropyl) trimethoxysilane (MPTMS) modified silica nanoparticles (SiO2-MPTMS) were successfully prepared. The average size of SiO2-MPTMS nanoparticles was measured by Dynamic Light Scattering (DLS) as 341 nm in ethanol, while Scanning Transmission Electron Microscopy (STEM) analyzes confirmed that the nanoparticles were nano-sized and revealed that their shapes were spherical. Then, 3D nanocomposite hydrogels were prepared by incorporating SiO2-MPTMS nanoparticles in various ratios (0.25, 0.50, 0.75 and 1.0 wt %) into an acrylate resin consisting of N-isopropyl acrylamide (NIPAM) and polyethylene glychol diacrylate (PEGDA; as a crosslinker) by the photoinitiated polymerization reaction with Dimethoxy-2-phenylacetophenone (DMPA; as a photoinitiator). By Thermal Gravimetric Analyzer (TGA) measurements, it was determined that the nanocomposite hydrogels maintained their thermal stability up to 330 0C and the thermal degradation steps were close to each other. Scanning Electron Microscopy (SEM) study showed that the neat and nanocomposite hydrogels’ morphological structures were in the porous and smooth scaffold, and also that the SiO2-MPTMS nanoparticles (0.50 wt %) were homogeneously distributed in the network structures of hydrogels, localized in the bonds.