Natural pterostilbene-grafted-chitosan for fabrication of ecological and durable antibacterial cotton fabric via lay-by-lay assembled coating

Abstract Natural antibacterial agents have tremendous potential for the fabrication of ecofriendly and durable antibacterial fabrics. Herein, natural pterostilbene (PL) was grafted onto chitosan (CS) by Mannich reaction to obtain PLCS with high antibacterial activity. Ecofriendly and durable antibacterial cotton fabric was fabricated via lay-by-lay assembled coating using PLCS as antibacterial agent. The results showed that under a molar ratio of CS and PL 1: 0.2 at 80 ℃, PLCS with grafting ratio of 17.3% attained the lowest minimum inhibitory concentration of 33.2 µg/mL and 16.6 µg/mL against S. aureus and E. coli, respectively. Compared with CS and PL, antibacterial activity of PLCS against S. aureus improved by 67.0% and 58.5%, and those against E. coli improved by 94.8% and 44.7%, respectively. Antibacterial rates of PLCS cotton fabric against S. aureus and E. coli reached up to 99.9% after 3 assembled layers and maintained more than 80% after 20 washing times. PLCS antibacterial fabrics possessed good wearing safety and wearing performances.