In situ-synthesis of calcium alginate nano-silver phosphate hybrid material with high flame retardant and antibacterial properties.

In this study, we demonstrate the in-situ synthesis of a functional hybrid material of calcium alginate (CaAlg)/nano-silver phosphate (nano-Ag3PO4). The morphology of nano Ag3PO4 was in spherical shape with a diameter of 10-60 nm, and uniformly distributed in the continuous phase of CaAlg. The limiting oxygen index (LOI) of the hybrid material reached 61.4%, which was about 53.0% higher than that of CaAlg. In addition, its heat release rate, total heat release and smoke emission were much lower than those of CaAlg. The thermogravimetric analysis coupled with Fourier transform infrared analysis and pyrolysis-gas chromatography-mass spectrometry results indicate that the synthesized material released less flammable gas, compared to CaAlg, and the thermal mechanism of CaAlg/Ag3PO4 was proposed based on the data. Furthermore, the antibacterial rate of the hybrid material against common pathogens was >97%. This study prefigures the promising application of the marine polysaccharide functional materials in the field of the fire protection and epidemic prevention.