Design, Preparation And Performance Study Of CNT/polyethersulfone Mixed Matrix Ultrafiltration Membrane

In this paper,the structure and function of polyethersulfone(PES)mixed matrix ultrafiltration membrane was taken as the main idea.PES mixed matrix ultrafiltration membrane was prepared by phase inversion method.The structure,antifouling and antibacterial properties of membrane were studied.PES is a commonly used ultrafiltration membrane material with good thermal stability and mechanical strength.However,hydrophobic surfaces of PES membranes readily adsorb organic contaminants in the water,leading to membrane fouling.In addition,biological contamination is another problem hindering the development of ultrafiltration membranes.As a kind of advanced nanomaterials,carbon nanotube(CNT)not only can transport water molecules efficiently,but also has good antimicrobial properties.In order to increase the antifouling and antibacterial properties of PES ultrafiltration membranes and improving the permeability,we designed and prepared CNT/PES mixed matrix ultrafiltration membrane(CNT/PES-MMM).We hope that the PES ultrafiltration membrane can be designed with high-performance,pollution-resistant,and bio-erodible abilities.In order to suppress the tendency of CNTs to agglomerate in solution,and form a hydrophilic surface to meet the need of membrane structure and functional design.In our work,CNTs were functionalized by non-covalent modification using sodium lignosulphonate(SLS),and the functionalized CNTs(f-CNTs)were characterized by Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM)and energy dispersive X-ray(EDX).The results showed that SLS has been successfully coated on the surface of f-CNT,and did not fall off during the membrane forming process.In our work,CNT/PES-MMM was prepared by phase inversion method.The separation and permeability,microstructure,surface hydrophilicity and mechanical properties of CNT/PES-MMM were studied.The water flux and mechanical properties of MMM were significantly improved.The SEM images showed that a large amount of CNTs appeared on the surface of CNT/PES-MMM.When f-CNT was used,the increase in water flux was more pronounced and all f-CNT-containing mixed matrix membranes had hydrophilic surfaces.Afterwards,the antifouling performance of CNT/PES-MMM was investigated in detail.The static adsorption experiments of bovine serum albumin(BSA)showed that the f-CNT-based mixed matrix membrane had the best antifouling ability.The results of dynamic cycling antifouling experiments were in good agreement with the results of BSA static adsorption experiments,and the antifouling performance of mixed matrix membrane increased with the improvement of f-CNT content.Finally,the antibacterial properties of PES mixed matrix membrane were investigated by the inhibition zone method.In order to take full advantage of the excellent electrical properties of CNT,a synergistic antibacterial experimental system including electric field and membranes was designed to explore the antibacterial properties of CNT/PES-MMM.The results showed that CNT/PES-MMM and electric field produced a strong synergistic antibacterial effect,and the mortality of E.coli close to 100%when the synergistic antibacterial experiments running for 3 h.