Gelation ofPolyisocyanurate Xerogel Composites Inducedby Silver Nanoparticles and Their Electrospun Fibers with Biocompatibleand Antibacterial Properties for Biomedical Applications

We report the in situ synthesis of silver-containing polyisocyanurate (Ag-PI) gels via the self-polymerization of isocyanate-containing organic molecules (Desmodur N75) catalyzed by silver nitrate (AgNO₃) in <i>N</i>,<i>N</i>′-dimethylformamide, which acts as both the solvent and reducing agent. Fourier transform infrared spectroscopy and X-ray diffraction confirmed the formation of polyisocyanurate and metallic silver nanoparticles. Gelation occurred in 30 min at 30 °C for Ag-PI, compared to 24 h for the uncatalyzed system, demonstrating AgNO₃’s catalytic role. Ag-PI gels exhibited superior compressive strength (up to ∼30 MPa with 74.3% bearing nature) compared to bare polyurea (∼6 MPa). Electrospun fibers (500–750 nm) and xerogels demonstrated excellent antibacterial activity against “Staphylococcus aureus” and “Escherichia coli” and were nontoxic to MG 63 cells, making them promising for tissue engineering applications.