Environmentally friendly assembly multilayer coating for flame retardant and antimicrobial cotton fabric

Abstract Potassium alginate (PA), a green polymeric material extracted from seaweed, was firstly coupled with environmentally friendly antimicrobial polyhexamethylene guanidine phosphate (PHMGP) to build flame retardant and antimicrobial coating on cotton fabric via layer-by-layer (LBL) technique. Attenuated total reflectance infrared spectroscopy analysis shows that PHMGP and PA grow linearly in LBL deposition process. Thermogravimetric analysis results indicate that the coated fabric leaves higher residue char than the uncoated after testing, owing to the char former feature of the assembly coating. Microcombustion tests show that the peak heat release rate and total heat release of fabric sample are decreased after coated with PHMGP-PA coating. The results of flammability tests reveal that the afterglow phenomenon was effectively eliminated by the PHMGP-PA coating. Scanning electron microscope and infrared spectroscopy results confirm that the assembly coating exerts useful intumescent flame retardant effect on cotton fabric. Furthermore, antimicrobial qualitative assessment reveals that the fabric coated with increased bilayers performs an improved antimicrobial effect on Escherichia coli ( E. coli ). The quantitative determination results show that the coated fabric can inactivate 100% E. coli and Staphylococcus aureus in 5 and 30 min, respectively.