Degradable, antibacterial and ultrathin filtrating electrospinning membranes of Ag-MOFs/poly(l-lactide) for air pollution control and medical protection.

The widely used melt-blown polypropylene (PP) non-woven fabrics had no antibacterial functions and its large-scale use also increased the burden on the environment owing to its non-degradable property. Herein, silver (I) metal organic frameworks (Ag-2MI) were prepared with AgNO3 and 2-methylimidazole and embedded into degradable poly(l-lactide) (PLLA) to make an ultrathin filtration and antibacterial membrane by electrospinning technology with low loading of Ag-2MI. The morphology, mechanical properties, adsorption performance and antibacterial activities of the prepared films were tested and the results indicated that the addition of Ag-2MI could reduce the diameter of PLLA fibers from 910 nm to 520 nm (1.8 wt% of Ag-2MI), while the tensile strength, elongation at break of the membrane and the contact angle of the films were enhanced. Although the thickness of the prepared membranes was only about one-third of that of commercially available melt-blown cloth, they exhibited better filtering performances than the melt-blown cloth. The fiber membrane with low loading of 1.8 wt% Ag-2MI showed 99.99% inhibition rate against Escherichia coli and Staphylococcus aureus.