Halloysite-based inorganic-organic hybrid coatings for durable flame retardant, hydrophobic and antibacterial properties of cotton fabrics

Developing durable protective cotton fabrics (CF) against potential environmental dangers such as fire hazards and bacterial growth remains an imperative but tough challenge. In this study, flame retardant, antibacterial and hydrophobic CF were successfully prepared via two-step coating. The inner coating entailed polyelectrolyte complexes consisting of polyethyleneimine and ammonium polyphosphate with the goal of enhancing the flame retardancy of CF. Halloysite nanotubes (HNTs), a kind of tubular silicate mineral, were creatively modified and introduced to multifunctional coatings to improve flame retardant and antibacterial properties of CF. N-halamine modified HNTs (HNTs-EA-Cl) and polydimethylsiloxane were applied as the outer coating to endow CF with antibacterial and hydrophobic properties and further improve the flame retardancy of CF. After halloysite-based inorganic-organic hybrid coatings, the limiting oxygen index of the treated samples (PAHP-CF) was over 28 %, and the release of heat and smoke was significantly inhibited. PAHP-CF could inactivate 100 % E. coli and S. aureus within 2 h. More importantly, PAHP-CF showed excellent hydrophobicity with a water contact angle of 148 degrees and exhibited great prevention of bacterial adhesion. PAHP-CF exhibited excellent washing durability undergoing 5 washing cycles. This study promotes the development of multifunctional coatings and offers a new way to manufacture multifunctional cotton fabrics.