Development and evaluation of UV-curable methacrylate-based hydrogel coatings

Abstract

The development of sustainable bioactive hydrogel coatings from renewable resources has gained significant attention as eco-friendly alternatives to petroleum-based systems. In this study, novel bio-based acrylate hydrogel coatings were successfully synthesized via UV- induced photopolymerization of citronella essential oil (CEO) with glycidyl methacrylate (GMA) using ethylene glycol dimethacrylate (EGDMA) as crosslinker and Irgacure 2959 as photoinitiator. GC-MS analysis of the native citronella oil identified citronellal (39.09%), geraniol (25.47%), citronellol (10.47%) and geranyl acetate (3.15%) as the major bioactive constituents. The crosslinked networks were extensively characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), swelling studies and antibacterial assays. FTIR spectra confirmed the presence of chemical interactions between GMA and citronellol fuctional groups in the samples with higher GMA content (GCE541 and GCE451), indicating successful incorporation of the essential oil into the polymer network. SEM revealed homogeneous surface morphology for optimized formulations, while swelling test demonstrated significant hydration capacity ranging from 9.23% to 77.1% depending on composition, indicating tunable hydrogel. Most notably, the optimized formulation (GCE541) exhibited potent broad-spectrum against Staphylococus aureus, and 6mm against Candida albicans (fungal strain). To our knowledge, this represents the first comprehensive study on UV-cured GMA/EGDMA hydrogel coatings incorporating CEO, demonstrating their potential as sustainable antimicrobial materials for biomedical and industrial applications.