A facile coating with water-repellent and flame-retardant properties on cotton fabric

A facile coating consisting of chitosan (CS), phytic acid (PA) and silicon dioxide (SiO2) modified with hexamethyldisilylamine (HMDS) was fabricated with a simple repeated coating technique and applied onto cotton fabric (CF) to achieve both superhydrophobicity and flame retardancy. SEM observation revealed that CS/PA/HMDS-SiO2 CF has a hierarchical rough surface. ATR-FTIR characterization results and XPS spectra verified the structure of the coating on the CF surface. The as-prepared coating on CF showed excellent waterproofing ability, mechanical stability and thermal stability in air. A flame test indicated the coating can protect cotton sample burning off. In particular, the coated CF still retained water-repellent and flame-retardant properties to some extent even after 50 abrasion cycles with sandpaper (400 cW). Hence, the coating on CF possesses potential application in outdoor clothing, equipment and the military.