Durable hydrophobic and antibacterial textile coating via PDA/AgNPs/ODA in situ assembly

Antibacterial textiles cannot prevent the dirty liquid containing bacteria from passing through the fabrics to reach the human skin, and cannot effectively protect human health. To enhance the antibacterial function of the fabric, a dual-function cotton fabric with hydrophobic and antibacterial properties, cotton@PDA@AgNPs@ODA, was prepared via in situ surface assembly of polydopamine (PDA), Ag nanoparticles (AgNPs) and octadecylamine (ODA). Polydopamine (PDA) was deposited on raw cotton fabric. AgNPs were introduced to the surface PDA coating of the fabric by in situ reduction of AgNO3 with reducibility of catechol moieties in PDA. Subsequently, octadecylamine (ODA) was grafted onto PDA by Michael addition/Schiff base reaction. Water contact angle of Cotton@PDA@AgNPs@ODA was 130° at 10 min of drop contact time, showing good hydrophobicity. The antibacterial rates of Cotton@PDA@AgNPs@ODA against Escherichia coli and Staphylococcus aureus were above 99%, and the modified fabric had good bacterial liquid shielding function. Furthermore, the PDA/AgNPs/ODA coating had good fastness under washing, mechanical abrasion and strong acid/alkaline conditions.