Preparation Of PVDF-PDMS Nanofiber Composite Membrane By Electrospinning And Its Oil-water Separation Performance

Membrane separation has the advantages of low cost,low energy consumption and high separation efficiency.It is widely used in the investigation of oil-water separation process.Compared with conventional membrane production technology,electrospinning technology has high porosity,permeation pressure,multi-stage coarse structuer,porous structure,controllable membrane thickness as well as pore size,It has a very extensive future in oil-water separation.Firstly,this paper studied the effect of preparation methods on membrane performance by comparing the performance of PVDF membranes prepared by NIPS,electrostatic spinning and electrostatic spinning with humidification.The membranes were described using SEM,ATR-FTIR,water contact angle,pore size,etc,testing membrane separation performance through paraffin water mixtures.The results show that the membranes prepared by the electrostatic spinning technique and the electrostatic spinning and humidification technique have higher mechanical strength and the membrane flux is as high as 462.76 kg/(m~2*h)with a separation effect of more than 99.55%,under the same composition of the cast membrane solution.In order to raise the separation efficiency of the membranes.PDMS is added to the PVDF solution.PVDF-PDMS nanofibre membranes were fabricated using an electrostatic spinning method.The effect of PDMS concentration on membrane structure and properties was investigated by characterising the membranes.The results showed that the water contact angle of the membrane achieved more than 150°.The membrane has a throughput of up to 1827.80kg/(m~2*h),the separation efficiency of 99.50%,higher than that of pure PVDF membranes.Finally,we prepared the PVDF-PDMS nanofiber membrane by spraying water vapor onto the electrospinning receiver to adjust the humidity of the operating environment.The membranes were characterized.The influences of humidity on the membrane were studied.The results showed that with the increase of humidity,the membrane fibers change from a loose and disordered structure to a tightly adhered whole,and the mechanical properties of the membrane are enhanced to 5210k Pa.The water contact angle of all membranes can reach more than 125°,the separation efficiency of treated oily wastewater reached more than 99%,the permeation permeation flux was 901.41 kg/(m~2*h)is slightly lower than that of the PVDF-PDMS nanofiber composite membrane prepared under non-humidified conditions.The above results show that the electrospun PVDF-PDMS nanofiber membrane has strong hydrophobicity and lipophilicity,has a remarkable separation effect,and has great potential in oil-water separation.