Super antibacterial polyamide composite membrane permeability
Clean water shortage is threatening more than 20 million people worldwide health. With the increasing population, the situation will deteriorate further. High-flux membranes plays an important role in addressing energy and water crises. Polyamide thin film composite membrane (TFCMs) reference materials dominate the market separation membrane for water treatment. Since the transmission rate is inversely proportional to the film thickness of the water, so that this conventional film exhibits moderate water permeation flux. Ultra-thin film can improve the water permeation flux, but the presence of the complex manufacturing process and high cost. Currently thicker films made of ultrahigh flux by a simple method remains challenging. Beijing University of Technology Anquan Fu and Huazhong University of Science Qiang (co-author), etc. people by a simple chemical change the method of achieved without lowering the thickness of the membrane was prepared hydrophilicity and water permeation flux of the membrane ultra clean water, to provide a high throughput film produced paradigm shift. relevant research results to the question \”Antibacterial Polyamide Composite Membranes with Unreduced Thickness\” published in \” Advanced Materials \”. 
In this work, using an inexpensive tetrakis (hydroxymethyl) phosphonium (of THPC) chloride directly modified polyamide composite membrane. Although the modified film thickness of 40nm is increased, but the water permeability increased 6 times, the permeate flux ratio prior polymeric nanofiltration membrane an order of magnitude. Meanwhile, under cross-flow conditions, the modified membrane exhibits good desalting properties and antibacterial properties. THPC modified polyamide film not only improves the hydrophilic film, the film also creates an unobstructed water transport channel.
Analytical graphic
ultrahigh-throughput filter (PIP-TMCTFCM) is prepared in a polysulfone supporting film was piperazine (PIP) and trimesoyl chloride (TMC) the interfacial polymerization reaction to prepare PIP-TMC TFCM. The (5 wt%) THPC solution was poured into a freshly prepared PIP-TMC TFCM (undried) and held for 10 minutes. By FTIR and XPS confirmed the manner hydroxyl group and esterification occurs (FIG. 1).
Further, THPC-5 TFCM interception rate of the dianion of to Na 2 SO 4 and MgSO 4 the retention rate was 98.4% and 93.8%, respectively. Further, THPC-5 ion-selective membrane (Cl – / SO 4 2- ) The calculated value of 48, which is the highest of the polyamide TFCMs one of the values. When Na 2 SO 4 concentration increased from 1000 ppm 7000 ppm, THPC-5 TFCM salt retention is still higher than 97.5%, indicating also suitable THPC-5TFCM in concentrated salt solution (FIG. 2).
concentrations had THPC-1TFCM and THPC-3 TFCM 1 THPC and 3 wt% of the modified PIP-TMC system. No membrane, the water flux of the modified membranes before modification and free volume were increased as compared with the increase of the concentration of THPC, increasing water flux of modified membrane and free volume, thanks to a relatively a large atomic radius and phosphorus THPC unique molecular tetrahedral structure, which will increase the free volume chamber. Moreover, Molecules of THPC having excellent water-binding capacity, increase the hydrophilic film. In general, despite the increase of THPC modified thickness of the film, but to create additional molecular passage, unobstructed water transport (FIG. 3).
containing BSA and sodium alginate, respectively by two cycles of water treatment, the membrane flux is recovered higher than 85%; post-treatment cycle two cycles Donghu water flux recovery rate of 92% . Furthermore, E. coli (Gram negative) and Staphylococcus aureus (Gram positive) 2 hours in contact with the film after THPC-5 effective to kill, show THPC-5 TFCM having excellent stain resistance and anti-bacterial sex. After b, c) for 24 hours;
Original link: https: //onlinelibrary.wiley.com/doi/10.1002/adma.202001383
