Flame-retardant, electrically conductive and antimicrobial multifunctional coating on cotton fabric via layer-by-layer assembly technique

A multifunctional coating composed of polyhexamethylene guanidine phosphate (PHMGP) and potassium alginate-carbon nanotubes (PA-CNTs) was constructed on cotton fabric via a layer-by-layer assembly technique. The growth of the assembly coating was monitored by Fourier transform infrared spectroscopy and the result shows the assembly coating grows approximately linearly with the increase of bilayer number. The electrical conductivity test shows that the assembly coating endows cotton with electrical conductivity, due to the formation of a CNT network on the cotton fabric. The thermo-stability and flame resistance were evaluated by thermo-gravimetric analysis and a vertical flammability test, and the results indicate that the assembly coating promotes char formation, decreases the burning time and eliminates the afterglow during combustion. The antimicrobial assessment suggests that the assembly coating can effectively inhibit the growth of Escherichia coli, and the inhibiting effect increases with the growth of bilayer number. A multifunctional cotton fabric could be produced by the LBL assembly technique, which enlarges its application area.