Preparation Of PPS And PVDF-HFP Based Hydrophobic Fiber Membranes And Their Oil/water Separation Performanc

The energy demand of oil extraction and recovery,the destruction of marine ecosystems and the pollution of aquatic environment have attracted a lot of attention.Therefore,it is urgent to solve the worldwide problem of oil/water separation.In recent years,the method of membrane separation technology has become a research hotspot of researchers due to its low energy consumption,low cost,and high efficiency.Fibrous membrane materials prepared by melt blowing,solution jet spinning,etc.were well used in oil/water separation due to their high porosity,high specific surface area,and easy regulation of fiber structure.However,the existing membrane materials still have some limitations in practical application,such as poor oil/water selectivity and corrosion resistance,complicated preparation process,etc.Therefore,the development of oil/water separation membranes that can be used in corrosive environments and produced on a large scale is still an urgent technical problem to be solved.Based on the above-mentioned problems,the contents of this paper are as follows:（1）Polyphenylene sulfide（PPS）fibrous membranes were prepared by melt-blown method.The fiber membranes were immersed in graphene oxide（GO）suspension for deposition.One deposition was 2 h,and the membranes were deposited for different times（2 times,4 times,6 times,8 times and 10 times）,and dried to obtain GO@PPS fiber membranes.Then,the GO@PPS fiber membrane was immersed in hydroiodic acid solution for reduction to obtain r GO@PPS fiber membrane.The effects of different deposition times on the hydrophobicity,mechanical properties,Joule heat and photothermal assisted crude oil adsorption,and oil-water separation of the composite fibrous membranes were investigated.The research results show that the r GO@PPS composite membrane deposited 8 times exhibits the best hydrophobicity,and the water contact angle can reach 149.4°.In the normal temperature environment,with the aid of Joule heat and simulated solar heat,the adsorption time decreased by 98.6%and 97.3%,respectively.At the same time,the flux reached 12903 L m^-2 h^-1 when separating oil/water mixture,and the separation efficiency was as high as 99.99%.In addition,the composite fiber membrane has good acid and alkali corrosion resistance,and can also be well used in harsh environments.（2）In order to improve the preparation efficiency of fibers and obtain nanofiber membranes with better hydrophobicity,we prepared PVDF-HFP fibrous membranes by solution jet spinning with low energy consumption,high efficiency,and wide application range.The production efficiency can reach 10 times that of electrospinning.Then,pine needle-like Ti O₂ nanorods were grown on the fibers by a two-step hydrothermal method to increase the rough structure of the fibers.Subsequently,the rough nanofibers were fluorinated by chemical vapor deposition,which greatly reduced the surface energy of the membrane,resulting in a superhydrophobic membrane surface with a water contact angle of up to 155°.The results show that the modified composite fibrous membrane exhibits excellent oil/water separation performance and recycling performance.After repeated recycling,the separation efficiency of the fibrous membrane is still higher than 99.95%and the permeation flux is as high as 9890 L m^-2 h^-1,and still retains a stable pine needle-like structure.