Eco-friendly and intrinsic nanogels for durable flame retardant and antibacterial properties

Fire hazard and public health security have become the main potential problems affecting human safety and health. Eco-friendly, healthy, and multi-function materials represent an inevitable tendency. In this research, nanogels of intrinsic flame retardance and antibacterial properties were prepared via Michael addition reaction. The resultant nanogels possessed regular, robust spherical morphologies and size-controllable properties, exhibited stable thermal performance and strong ability to kill bacteria. The antibacterial efficacy reached to more than 99.9% for both Staphylococcus aureus and Escherichia coli when being exposed in nanogel suspension at the concentration of 120 μg/mL. Moreover, anti-infection experiments were explored by in vivo wound model confirmed that the nanogels had capability to prevent infection, and the healing efficiency reached 97.7% after 14 days' treatment. By grafting on the cotton fibers and fabrics, the nanogels displayed excellent flame retardancy protection of the matrix. The peak of heat release rate (pHRR) reduced by 41.2% compared with raw cotton fabric and the total heat release (THR) declined by 24.4%. In addition, the usage of nanogels could reduce the grafting ratio and improve the functionality, which effectively saved resource and decreased the damage of matrix. The durability test demonstrated the nanogels were ideal candidate for nanoscale materials with durable flame retardant and antimicrobial.