Research On Micropore Control And Performance Of Solution Jet Spinning Micro/Nano Fiber Filtration Membrane

A novel solution blowing process driven by high speed airflow has a lot of advantages:a wide range of materials sources,smaller diameters,high produce efficiency and more safe and convenient operation.It has a good prospect in large-scale production.In this paper,based on the new solution blowing device,the application of solution blowing nanofibers in water treatment was studied.The main contents are as follows:The microfiltration membrane with multiscale fibers was designed based on the concept of multilevel fiber.The LPET nanofiber dispersion was mixed with the PET staple fiber evenly and the mixed structure was produced by wet-laid method.Encouragingly,after hot pressing treatment,the pore structure of microfiltration membrane was effectively adjusted(the pore size decreased from 55.6 ?m to 15.29?m),and its strength was significantly enhanced.In addition,the filtration efficiency is also high,the remove rate of PS microsphere with 5,3 and 1.3?m in diameter is 99%.Referring to the composite preparation nanofiltration membrane method,the PA6 nanofiber membrane prepared with solution blowing process was used to replace the membrane prepared with phase inversion method.After hot pressing,the nanofiber porous base film with a gram weight of 9.4 and 14.1 g/m2 has a better apparent structure,greater strength,smaller pore size and higher porosity.The average pore diameter and porosity are 1.358,1.0624 ?m and 83.4,85%,respectively.At the same time,different gram weight porous membranes also have an important influence on the structural properties of the nanofiltration membrane.When the gram weight of the nanofiber porous base membrane is 9.4 and 14.1 g/m2,the prepared nanofiltration membrane has a smooth surface and the most outstanding filtration performance.It is pure water flux and Na2SOa filtration efficiency are 13.2,13.1 Lm-2h-1 and 84.7,85.1%,respectively.The wet-laid process was used to re-mesh the nanofibers,readjusted the fiber accumulation,enhance the strength of the membrane,and improve the uniformity of the pore size.Compared with the membrane prepared by one-step process of solution blowing technology,the wet-laid nanofiber membrane is improved in microscopic uniformity,surface roughness and the strength of membrane.With improved of uniformity and surface flatness,the nanofiltration membrane prepared with wet-laid nanofiber membrane is superior to the one prepared with the one-step solution blowing membrane.The membrane of 10 and 14 g/m2 in gram weight show the best comprehensive performance.Their average pore size and porosity are 0.6997,0.5843?m and 80.1,83.7%,respectively.What's more,with the best pure water flux and Na2SO4 filtration efficiency of 10.9,10.4 Lm-2h-1 and 94.8,96.1%,respectively.