Preparation And Performance Study Of Zr-Based MOFs Materials/PES Mixed Matrix Membranes

Polyether sulfone（PES）,as a common organic polymer membrane material,is widely used in water treatment due to its excellent mechanical and chemical properties.However,due to its hydrophobicity,the PES membrane is prone to combine with organic substances such as proteins in water during filtration,resulting in pollution,ultimately leading to a decrease in the permeability and retention performance of the PES membrane.Therefore,improving the hydrophilicity of PES membranes to enhance their anti-fouling performance has always been a focus in the field of membrane separation.In this experiment,the nonsolvent induced phase separation（NIPS）method was used to prepare UIO-66/PES,Ti O₂/UIO-66/PES,UIO-66/MWCNTs-COOH/PES and UIO-66/MWCNTs-COOH/PES mixed matrix membranes using hydrophilic Zr-based MOFs materials（UIO-66,Ti O₂/UIO-66,UIO-66/MWCNTs-COOH）as blending modifiers.Scanning electron microscope（SEM）,atomic force microscope（AFM）,water contact angle tester,water flux,retention rate,anti-pollution performance test and other characterization methods were used to explore the influence of Zr based MOFs materials on the hydrophilicity,permeability,retention,and anti-pollution performance of PES membrane under different additive content.The main content is as follows.Firstly,the UIO-66 MOFs material was synthesized by solvothermal method under the conditions of n(Zr⁴⁺):n（H₂BDC）=0.5 and T=160℃.Then,the UIO-66/PES mixed matrix membranes were prepared using NIPS,and its hydrophilicity,permeability,retention performance,and anti-pollution performance were investigated.Through experiments,it is found that when the content of UIO-66 is 0.6 wt%,the pure water flux of the UIO-66/PES mixed matrix membrane reaches 89.86 L/（m²·h）,the water contact angle is 62.2°,the rejection rate of BSA is 89.64%,and the average surface roughness（Ra）is 5.16 nm.The results show that the addition of UIO-66 improves the permeability,hydrophilicity,and anti-fouling performance of the PES membrane.Secondly,Ti O₂/UIO-66 composite materials were further synthesized based on UIO-66MOFs materials,and Ti O₂/UIO-66/PES mixed matrix membranes were prepared through NIPS.The experimental results show that when the Ti O₂/UIO-66 content is 1.0 wt%,the pure water flux reaches 129.28 L/（m²·h）,the water contact angle is 64.48°,the rejection rate is 91.02%,the average surface roughness decreases by 3.92 nm,and the flux recovery rate increases from65.09%to 81.24%.The doping of Ti O₂ and UIO-66 further improves the permeability,retention,and anti-fouling properties of PES membranes.Thirdly,the UIO-66/MWCNTs-COOH composite material was successfully synthesized by solvothermal method,and the UIO-66/MWCNTs-COOH/PES mixed matrix membranes were prepared using NIPS.When the addition amount of UIO-66/MWCNTs-COOH is 1.3 wt%,the performance of the UIO-66/MWCNTs-COOH/PES mixed matrix membrane is the best,with a water flux of 325.28 L/（m²·h）,which is 7.62 times that of the pure PES membrane.The water contact angle is 50.11°,the surface roughness is reduced by 3.32 nm,and the flux recovery rate is increased from 65.09%to 87.79%.The above results indicate that the addition of UIO-66/MWCNTs-COOH composite material significantly improves the hydrophilicity,permeability,and pollution resistance of PES.