Superhydrophobic cotton gauze with durably antibacterial activity as skin wound dressing

Common cotton gauze was endowed with both superhydrophobic and antibacterial properties by a dip-coating method that involved sequential deposition of positively charged chitosan (CS), negatively charged gallic acid modified silver nanoparticles (GA@AgNPs) and 1H,1H,2H,2H-perfluorodecanethiol (PFDT) with low surface energy on cotton fabrics. After such surface coating, the wettability of gauze surface was converted from superhydrophilic to superhydrophobic with a water contact angle (CA) of 158 ± 2.2° and sliding angle (SA) of 5.2 ± 1.8°, exhibiting water repellency, antifouling ability as well as bacterially antiadhesive activity. Moreover, such PFDT/GA@AgNPs/CS-coated cotton fabrics showed efficiently antibacterial activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which was mainly attributed to the synergistic effect of contact-killing of CS and continuous release of Ag+. In addition, it was found that the outer PFDT deposition could act as a barrier to prevent leaching of the AgNPs during laundry, enhancing the antibacterial durability.