Preparation and performance of regenerated cellulose/polylactic acid non-leaching antibacterial composite membrane

Composite membranes with excellent antibacterial properties, hydrophilic/hydrophobic differentiation, and selective permeability are preferred materials for wound dressings. In this work, antibacterial bromoacetyl and quaternary ammonium groups were chemically introduced into a regenerated cellulose nanofiber membrane. This hydrophilic membrane was then compounded with a polylactic acid (PLA) liquid film through a non-solvent-induced phase separation process to prepare a composite membrane. FTIR, XPS, and EDS results confirmed the successful chemical modification and presence of antibacterial groups. SEM analysis revealed a stable composite with an asymmetric structure. Modification time, particularly the bromoacetylation duration, had a certain impact on the structure and properties of the composite membrane. The optimized composite membrane exhibited excellent gas permeability (air and water vapor) and differentiated hydrophilic/hydrophobic properties. Membrane modified via bromoacetylation for over 3 h demonstrated >95 % antibacterial efficiency against Escherichia coli and Staphylococcus aureus , indicating broad-spectrum efficacy. The biomass-derived polymer matrix, scalable production process, and multifunctionality highlight its potential for healthcare applications, particularly in wound dressings.