Silica nanoparticles (G-SiNPs) blocked with 3-glycidoxypropyl trimethoxysilane (GPTS) were newly applied to hydrogel films for improving film coating properties and to distribute the epoxy groups on the film surface. The effects of the content of epoxy-functionalized G-SiNPs on the crosslinking features by photo-induced radical polymerization and the surface mechanical properties of the hydrogel films containing poly(ethylene glycol) dimethacrylate (PEGDMA) and glycidyl methacrylate (GMA) were investigated. The real-time elastic modulus of various PEG hydrogel mixtures with prepared particles was monitored using a rotational rheometer. The distribution of epoxy groups on the crosslinked film surface was directly and indirectly estimated by the elemental analysis of Si and Br. The surface mechanical properties of various hydrogel films were measured by nano-indentation and nano-scratch tests. The relationship between the rheological and surface properties of PEG-based hydrogel films suggests that the use of small amounts of G-SiNPs enhances the surface hardness and crosslinked network of the film and uniformly distributes sufficient epoxy groups on the film surface for further coating applications.
Bibliographical noteFunding Information:
Funding: This research was supported by the Ministry of Trade, Industry & Energy (MOTIE, Korea) under the Industrial Technology Innovation Program (grant numbers 20004044 and 20010256) and the Korea Research Institute of Chemical Technology (KRICT) Research and Development (R&D, SS2141-10) program.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Epoxy group
- PEG hydrogel
- Rheological properties
- Silica nanoparticles
- Surface properties
- UV crosslinking
ASJC Scopus subject areas
- Polymers and Plastics