Hybrid nanoparticles based on novel Schiff Base for durable flame retardant and antibacterial properties

A large amount of cellulose is produced by photosynthesis every year, and cellulose products are widely used in daily life. However, flammability and easy to breed bacteria of cellulose has hidden risk of fire and public health during using, and the materials that can endow cellulose with flame retardancy and antibacterial properties is still lacking. Herein, novel hybrid nanoparticle (SiDP) based on inorganic nano SiO2, Schiff base and quaternary ammonium salt was developed to synchronize these two properties. Wherein the thermal stability of nano SiO2 and the cross-linking structure of Schiff base played as synergistic flame retardant for the nanoparticle while quaternary ammonium salt of N, N′-dimethyl-N-(3-(trimethoxy silyl) propyl) octadecan-1-aminium chloride (DMOAC) was introduced to provide antibacterial property. The results demonstrated that the modified cotton fabrics were significantly out-performing of flame retardancy and antibacterial properties. Wherein LOI increased to 27.6%, the peak of heat release rate (pHRR) reduced by 34.2%, and capability of self-extinguishing was achieved. The antibacterial of SiDP and modified cotton fabrics were substantiated up to 99.9% against the Staphylococcus aureus and Escherichia coli. More excitingly, low toxicity of SiDP was confirmed via MTS assay by L929 fibroblast cells. The anti-infection in-vivo model was constructed and confirmed SiDP had a positive prevention of infection based on the wound healing rate of 91.1% after 14 days' treatment. The flame retardancy, antibacterial and biocompatibility of SiDP indicated it was an ideal candidate of nanomaterials in cellulose modification.