| Membrane separation technology has become a new generation of separation technology due to its economical,efficient and environmentally friendly advantages.Membrane materials are the core of membrane separation technology,and the development of membrane materials is crucial.Graphene materials have unique advantages in many aspects and have become a research hotspot for new membrane materials.As one of the important derivatives of graphene materials,graphene oxide（GO）has the advantages of good hydrophilicity and controllable interlayer spacing,and has a wide range of application prospects.The adjustment of the GO layer spacing can improve the permeability and selectivity of the GO membrane,which has important research value for improving the separation performance of the membrane.In this thesis,different nanofibers are selected for doping GO,and the PVDF hollow fiber membrane with internal woven mesh support is used as the substrate,and the GO@hollow fiber composite membrane intercalated with nanofibers is prepared by the method of vacuum filtration.The membrane was characterized by various methods,and the pure water flux of the composite membrane and the retention performance of BSA and dye were tested,and the following results were obtained:（1）Through the vacuum filtration method,the mixed dispersion of nanofiber and GO is deposited on the outer surface of the PVDF hollow fiber membrane,and a uniform and complete composite membrane can be obtained.The layer spacing of the composite film increases with the increase of the doping amount of nanofibers.The PVDF hollow fiber membrane with internal woven mesh support is more resistant to vacuum filtration than the unsupported PVDF hollow fiber membrane,is not prone to deformation under pressure,and can meet high-pressure operating conditions in the test.（2）XRD and SEM results show that the nanofibers are successfully inserted between GO layers,and the more doping,the greater the interlayer spacing of the composite film.Ti O2nanofibers are rigid,and some nanofibers cannot be completely inserted between the GO layers and are exposed on the surface of the composite film,causing certain defects.The surface of PANI intercalated GO composite film is more complete and defect-free.The water contact angle test shows that GO intercalated with nanofibers can improve the hydrophilicity of PVDF hollow fiber base membranes.The more intercalated,the better the hydrophilicity.The GO composite membrane intercalated with Ti O2 nanofibers is more hydrophilic than PANI intercalated GO composite film.（3）When the mixed dispersion liquid has a certain suction volume,the permeation flux of the composite membrane increases with the increase of the doping amount of nanofibers,and the interception performance decreases accordingly;when the doping amount of nanofibers is constant,the permeation of the composite membrane The amount decreases with the increase of the suction volume,and the retention performance increases accordingly.The pure water flux of the composite membrane with Ti O2 nanofibers as the dopant is 230.8Lm-2h-1bar-1 at the highest,BSA rejection rate is the highest 96.2%,Rh B rejection The highest rate is 93.4%,EB rejection rate is the highest 99.00%.The pure water flux of the composite membrane with PANI nanofibers as the dopant is the highest 123.3Lm-2h-1bar-1,the rejection rate of BSA is the highest98.6%,the rejection of Rh B The highest rate is 96.6%,the rejection of EB The highest rate is99.46%.The composite membranes prepared by HGO with H2O2 etching and nanofiber intercalating can significantly improve the permeation flux without loss of selectivity.（4）Compared with Ti O2 nanofibers,PANI nanofibers are smaller in diameter,flexible,and compacted,which may cause the composite membrane to have a narrower penetration channel,resulting in the water flux of the GO composite membrane intercalated with PANI nanofibers being lower than that of Ti O2 nanofiber intercalation.GO composite membrane,but with higher selectivity. |
