Dual-functional HACC@OTS coating for durable hydrophobic and antibacterial fabrics in self-cleaning and anti-bloodstain adhesion applications

The majority of hydrophobic coatings in protective fabrics use expensive and environmentally harmful fluorine-based chemicals, which makes sustainable substitutes desperately needed. In this study, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) and octadecyltrichlorosilane (OTS) are combined via vacuum impregnation and straightforward spray-assisted assembly to create long-lasting hydrophobic and antibacterial fabrics without the use of fluorine. Both polyester (PET) and cotton fabrics coated with 6 %HACC@OTS exhibit strong resistance to common pollutants (milk, coffee, vinegar, tea, and cola) and synthetic blood without compromising gas permeability. They also achieve good hydrophobicity, with the WCA of 150.05 ± 0.91° and 146.96 ± 1.21°, respectively. The quaternary ammonium groups in HACC impair the permeability of bacteria's cell membranes, resulting in a powerful antibacterial activity against E. coli and S. aureus . Additionally, the alkyl chains obtained from OTS combine to efficiently preserve hydrophobic durability and antibacterial stability even after the coating has been repeatedly treated in harsh environments (abrasion, washing, ultraviolet light, acid and alkali solution, and ultrasonic treatment). Furthermore, 6 %HACC@OTS coating can be applied to a variety of rigid (glass, aluminum, wood, stone) and flexible (plastic, filter paper) surfaces due to its broad range of substrate compatibility. This scalable, environmentally friendly approach is in line with green manufacturing principles and presents a viable option for multipurpose textiles in protective gear, functional clothing, and healthcare.