Cao Hongbin, research team of Institute of process engineering, Chinese Academy of Sciences, proposed a new method for preparing polytetrafluoroethylene hollow fiber membrane

Recently, the Cao Hongbin research team of the Institute of process engineering, China Academy of Sciences proposed to prepare a new type of polytetrafluoroethylene (PTFE) hollow fiber membrane based on nanofiber assembly by means of emulsion electrospinning Compared with the PTFE hollow fiber membrane prepared by the traditional mechanical stretching method, the membrane has the advantages of nanofiber membrane (high porosity) and hollow fiber membrane (self-supporting and high loading density) The whole membrane preparation process does not need to use organic solvents and lubricants, which realizes the new breakthrough of green preparation and membrane performance of PTFE hollow fiber membrane PTFE is considered as an ideal hydrophobic membrane material because of its excellent corrosion resistance, thermal stability and hydrophobicity, but it is difficult to be dissolved, poor melting fluidity and processing At present, the only processing method of PTFE hollow fiber membrane is mechanical stretching, but the porosity of the membrane prepared by this method is low, which seriously restricts the efficiency of the separation process Cao Hongbin, a research team from the Institute of process engineering, Chinese Academy of Sciences, proposed that PEO with high viscosity and easy thermal decomposition of aqueous solution was used as binder and PTFE particles to mix into aqueous spinning solution, and non rotating linear electrode was used as the receiver for continuous preparation PEO coated PTFE particles were stretched into PTFE / PEO hybrid nanofibers under high voltage, and the initial film was formed on the electrode After sintering at a certain temperature, the PEO molecules in the initial membrane are completely decomposed, and the PTFE particles melt into nanofibers, which are then bonded by the fiber nodes to form the target PTFE hollow fiber membrane The steam flux of the membrane is 4.6-8.8 times of that of commercial PTFE hollow fiber membrane and 3.2-11.6 times of that reported in literature The micro nano multistage structure of the fiber endows the membrane with super hydrophobicity, which shows high and stable desalination performance in the membrane distillation experiments with long time and rising salinity, indicating that it has a good application prospect in the fields of desalination, high salt wastewater treatment, etc Relevant achievements were published in Journal of Membrane Science (J membr SCI 2019, 583, 200-208) The above work is supported by NSFC and national key R & D programs.