Investigation On Psf Ultrafiltration Membrane Embedded By Phosphorylated Zr_xSi_1-xO₂ Coated TiO₂ Nanotube

The comprehensive properties of polymer membranes can be improved by preparing and embedding small scale inorganic functional materials into polymers.This method has been widely studied due to the controllable structure and properties of the functional materials and the rich source of raw materials.However,the interaction between the embedded inorganic functional materials and the polymer plays a crucial role in membrane performances,therefore it has become one of the key and urgent problems to be solved in present research.In this paper,the phosphorylated Zr_xSi_1-x-x O₂ coated TiO₂ nanotube（PZr-SVTNT）was designed and synthesized,and then embedded into polysulfone（PSF）to prepare ultrafiltration（UF）membranes.The properties of the materials and seawater cleaning performance of the UF membranes were studied.Therefore,the research has good theoretical significance and application prospect.In this paper,TiO₂ nanotube was prepared by hydrothermal reaction,then coated by oleic acid.After that,Zr_xSi_1-x-x O₂ coated TiO₂ nanotube was obtained via hydrolysis of CTAB,TEOS and ZrOCl₂?8H₂O and calcination of oleic acid layer.Then the nanotube was modified by silanylation and phosphorylation,and the phosphorylated Zr_xSi_1-x-x O₂ coated TiO₂ nanotube was finally prepared.The characterizations of SEM,TEM,FT-IR,XRD and BET were tested and analyzed.Then the PZr-SVTNT/PSF UF membrane with strong hydrophilicity,anti-fouling and anti-compaction properties was prepared by embedding PZr-SVTNT into PSF,and then the performances of the ultrafiltration membrane were studied by pretreating seawater,which were compared with SZP/PSF hollow fiber ultrafiltration membrane.The interaction between PZr-SVTNT and PSF was investigated by FT-IR characterization.The influences of this interaction on the permeation flux,hydrophilicity,anti-compaction property of PZr-SVTNT/PSF ultrafiltration membrane were studied.The distribution of PZr-SVTNTs in PSF was observed by SEM.Moreover,the influence of reaction temperature on the formation of hydrogen bonds between PZr-SVTNT and PSF chains was investigated.The results show that PZr-SVTNT presents a typical tubular core-shell structure,and the TiO₂ nanotube core exhibits a length of 100-300 nm,outer diameter of 40-50nm,wall thickness of 2-7 nm,and the Zr doped SiO₂ shell is a porous structure with a thickness of 4.5-9 nm.The particles present photocatalytic property and the photocatalytic degradation ratio for methyl orange is 27.03%（40 min）.The suitable embedding amount of PZr-SVTNT particles is m（PZr-SVTNT）:m（PSF）=10:100（g:g）.When embedded PZr-SVTNT particles into PSF,PZr-SVTNT can interact with PSF through hydrogen bonds to improve the mechanical and anti-compaction performances of PSF membrane.The results show that the tensile strength of the PZr-SVTNT/PSF UF membrane is 3.46 MPa and flux of the deionized water（DI water）at 0.10 MPa is 318.96 L/（m²?h）,showing favorable mechanical and anti-compaction performances.In addition,under appropriate reaction temperature,the mutual interactions between PZr-SVTNT and PSF chain can be enhanced via the formation of hydrogen bonds,thus contributing better hydrophilic and anti-compaction performance of PSF membrane.The permeate seawater quality treated by PZr-SVTNT/PSF UF membrane is as below:suspension of 2.2 mg/L,turbidity of 0.01 NTU,COD of 22.9 mg/L,suspension retention ratio of 96.21%,COD change ratio of 53.17%,which satisfies the feed water quality standards of reverse osmosis（RO）membranes.On the basis of the aforementioned study,it is concluded that the PZr-SVTNT/PSF UF membrane with good hydrophilicity,anti-compaction and anti-fouling performances is expected to achieving potential applications in seawater pretreatment.