Preparation Of Micro/Nano Filtration Membranes By Needleless Melt Electrospinnig Methods And Its Application On Water Filtration Properties

The melt electrospinning has attracted great attention from the academic and industry because of it’s no solvent, green environmental protection, high efficiency and stability compared with solution electrospinning. At present, the industrialization of melt electrospinning technique have not been achieved, so the research of the electrospun membrane application is few. Based on this, systematic research of water filtration properties about the electrospun membranes was taken in this article. The main contents are as following:(1) Based on the fiber membrane prepared by our melt differential electrospinning device,2D porous media and 3D solid models are set up. Then using the analysis software FLUENT to simulate the process of the liquid- solid separation, and the influence of the initial filtering velocity, pressure drop, film thickness and pore size distribution on the filtration efficiency are also studied. Give advice to optimize the structure and parameters of membrane.(2) The influence of arrangement for oriented fiber membranes on the filtration efficiency is studied. Explore the preparation of oriented fibers combining the electric field simulation with experimental study. The preparation process of the oriented fibers in this study is:the distance of the nozzle-to-electrode was 8cm, the voltage of the electrode was 50kV, and the rotating speed of the cylinder was 1300rpm. Experimental results demonstrated that electrospun oriented membranes showed higher efficiency than the native membrane. The interval angle of adjacent membranes was more uniform, the water flux and rejection ratio would be greater. The best filtration efficiency is the 60 angle which can reach 98.5% to 0.5μm particles.(3) New composite polyvinyl alcohol (PVA)/polypropylene (PP) membranes were prepared by combining both solution electrospinning and melt electrospinning methods. The rejection ratio to the 500nm particles of the PVA/PP composite membrane could reach more than 96%, which was much larger than that of the PVA/non-woven substrate of 90%, and the melt electrospun PP membrane of 80%, and still maintained high permeate flux of 32,346L/m2h under the pressure of 0.24bar. This approach of compositing the solution electrospun membranes and melt electrospun membranes could be useful in designing novel microfiltration membrane owning both higher flux and higher rejection ratio.