Preparation And Properties Of Polysulfone/Nano-TiO₂ Organic-Inorganic Hybrid Hollow Fiber Ultrafiltration Membrane

In this study,organic-inorganic hybrid polysulfone?PSF?/titanium dioxide?TiO₂?hollow fiber ultrafiltration?UF?membranes were prepared by combination of sol-gel process and dry-wet spinning method.Through SEM,FT-IR,DSC,TGA,contact angle goniometer,ultrafiltration performance experiments,etc.,the relationship between the addition of TiO₂ nanoparticles and the performance of PSF/TiO₂ hollow fiber membranes was mainly studied,and effect of optimized spinning process on the properties of PSF/TiO₂hollow fiber membranes.Finally,the appropriate amount of TiO₂ nanoparticles and the optimal process parameters were determined.Through the mutual cooperation of the two,PSF/TiO₂ organic-inorganic hybrid hollow fiber ultrafiltration membranes with high permeability,high pollution resistance and high performance can be prepared.In the experiment,the spinning solution was formulated as PSF,additive polyvinylpyrrolidone?PVP?,solvent dimethylacetamide?DMAc?,and TiO₂ sol.The sol-gel method can effectively disperse nano-TiO₂ in PSF matrix.Through testing various properties of the hollow fiber membrane,the results show that the structure of the hollow fiber membrane is composed of a dense skin layer,a double row of large finger-like pore structures and a support layer,and the membrane support layer is a network structure.The organic-inorganic network structure formed between the TiO₂ nanoparticles and the PSF chain introduced by the sol-gel method leads to an increase in the porosity,mechanical strength and thermal stability of the membrane.The addition of TiO₂ sol also improved the ultrafiltration performance,hydrophilicity and antifouling performance of the membrane.However,when the TiO₂ concentration is high,nano-particle aggregation will occur,resulting in a decrease in membrane ultrafiltration performance and hydrophilicity.Comprehensive properties,the PSF/TiO₂ hybrid hollow fiber membrane with 2wt%TiO₂sol was the best.The spinning parameters discussed in this paper include dry spinning process,core fluid flow,coagulation bath temperature and winding speed.These parameters have important effects on the structure of the PSF/TiO₂ hollow fiber membrane during the spinning process.The dry spinning process mainly plays an important role in the compactness of the surface structure of the hollow fiber membrane.The core fluid flow has a significant relationship with the inner surface structure of the hollow fiber membrane and the density of the inner diameter.The change of the winding speed mainly has a greater impact on the outer diameter of the membrane,and increasing the speed can reduce the outer diameter of the membrane and the inner diameter does not change much.The increase of coagulation bath temperature can promote the performance of PSF/TiO₂ hollow fiber membrane.Therefore,these parameters should be optimized during the spinning process to obtain PSF/TiO₂ hollow fiber ultrafiltration membranes with better performance.