Chitosan/tannic acid bilayers layer-by-layer deposited cellulose nanofibrous mats for antibacterial application

The research and development of environmentally friendly and nontoxic biomass products has become an important topic of worldwide concern. In this study, natural materials were used for producing a kind of antibacterial mats. Cellulose acetate (CA) mats prepared by electrospinning technology were converted to cellulose mats via alkali hydrolysis. Chitosan (CS) and tannic acid (TA) were used to fabricate the composite mats by using layer-by-layer (LBL) self-assembly technology. The cellulose mats exhibited good fibrous structure, three-dimensional network and small average fiber diameter ranging from 300 to 400 nm. Besides, the results of mechanical properties testing and water contact angle measurements of these LBL-structured mats demonstrated that the LBL technology was able to improve their surface characteristics, hydrophilicity and mechanical properties. The analysis of antibacterial activity of the mats revealed over 86% antibacterial activity against Escherichia coli and up to 99% antibacterial activity against Staphylococcus aureus. Hence, the LBL-structured cellulose mats have excellent antibacterial activity and mechanical properties. Therefore, these nano-cellulose mats can be expected to have considerable development prospects for food packaging or wound dressing.