Fabrication of firm, superhydrophobic and antimicrobial PVDF@ZnO@TA@DT electrospun nanofibrous membranes for emulsion separation

Due to its minute droplet size and stability, separation of the emulsion is a non-negligible challenge. In this paper, polyvinylidene fluoride (PVDF) nanofibrous membranes were prepared via the electrospinning method. The nanofibrous membranes were subsequently surface-modified by ZnO nanoparticles, tannic acid (TA), and n-dodecyl mercaptan (DT), in order to reduce the nanofiber membranes' surface energy while increasing their surface roughness. Thus, superhydrophobic and antibacterial nanofibrous membranes have been fabricated for oil-water emulsion separation. The as-fabricated nanofibrous membranes have a water contact angle of 156.5 degrees. The product has a porosity of up to 73.3% due to the high porosity of the electrospinning nanofibrous membranes. In addition, the tensile strength of the PVDF@ZnO@TA@DT nanofibrous membrane is up to 69.25 MPa. Due to these properties, oil droplets can pass through the membrane during the oil-water separation, while the water phase is blocked by the membrane. This results in a good selective permeability of the membrane. As a result, the separation efficiency of the PVDF@ZnO@TA@DT nanofibrous membranes reaches more than 99%, and the flow flux is 1008.88 L.m(-2).h(-1). At the same time, antimicrobial testing demonstrates that the nanofibrous membranes have a bacteriostatic rate of over 98%. Combined with these properties, PVDF@ZnO@TA@DT electrospun nanofibrous membranes have great potential for efficient emulsion separation and deep purification of wastewater.

Automated summary

In this study, polyvinylidene fluoride (PVDF) nanofibrous membranes were prepared via the electrospinning method and then surface-modified by ZnO nanoparticles, tannic acid, and n-dodecyl mercaptan to achieve superhydrophobic and antibacterial properties. The resulting membranes exhibited a water contact angle of 156.5 degrees, a porosity of up to 73.3%, and a tensile strength of 69.25 MPa. The PVDF@ZnO@TA@DT nanofibrous membranes demonstrated a separation efficiency of more than 99% and a flow flux of 1008.88 L.m(-2).h(-1) for oil-water emulsion separation. Antimicrobial testing showed a bacteriostatic rate of over 98%. These electrospun nanofibrous membranes have great potential for efficient emulsion separation and wastewater purification.