Facile surface modification of PVDF microfiltration membrane by strong physical adsorption of amphiphilic copolymers

To endow the surface of poly(vinylidene fluoride) (PVDF) microfiltration (MF) membranes with hydrophilicity and antifouling property, physical adsorption of amphiphilic random copolymers of poly(ethylene glycol) methacrylate (PEGMA) and poly(methyl methacrylate) (PMMA) (P(PEGMA‐r‐MMA)) onto the PVDF membrane was performed. Scanning electron microscopy (SEM) images showed that the adsorption process had no influence on the membrane structure. Operation parameters including adsorption time, polymer concentration, and composition were explored in detail through X‐ray photoelectron spectroscopy (XPS), static water contact angle (CA), and water flux measurements. The results demonstrated that P(PEGMA‐r‐MMA) copolymers adsorbed successfully onto the membrane surface, and hydrophilicity of the PVDF MF membrane was greatly enhanced. The antifouling performance and adsorption stability were also characterized, respectively. It was notable that PVDF MF membranes modified by facile physical adsorption of P(PEGMA₅₈‐r‐MMA₃₃) even showed higher water flux and better antifouling property than the commercial hydrophilic PVDF MF membranes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3112–3121, 2013     

Antifouling microfiltration membranes prepared from poly(vinylidene fluoride)‐graft‐Poly(N‐ vinyl pyrrolidone) powders synthesized via pre‐irradiation induced graft polymerization

Poly(vinylidene fluoride) (PVDF) powders were grafted with N‐vinyl pyrrolidone using the pre‐irradiation induced graft polymerization technique. The effects of reaction time, absorbed dose, and monomer concentration on the degree of grafting were investigated, and the grafted PVDF powders were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The grafted PVDF powders were also cast into microfiltration (MF) membranes via the phase‐inversion method. The contact angle and water uptake were measured. The membrane morphology was studied by scanning electron microscopy, and the water filtration properties of the membranes were tested. The antifouling properties were determined through measurements of the recovery percentage of pure water flux after the MF membranes were fouled with bovine serum albumin solution. The results confirmed that the existence of poly(N‐vinyl pyrrolidone) (PVP) graft chains improved the hydrophilicity and antifouling properties of the MF membranes cast from PVDF‐g‐PVP powders. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Amphiphilic poly(vinyl chloride)‐g‐poly[poly(ethylene glycol) methylether methacrylate] copolymer for the surface hydrophilicity modification of poly(vinylidene fluoride) membrane

In this study, a comblike amphiphilic graft copolymer containing poly(vinyl chloride) (PVC) backbones and poly(oxyethylene methacrylate) [poly(ethylene glycol) methylether methacrylate (PEGMA)] side chains was facilely synthesized via an atom transfer radical polymerization method. Secondary chlorines in PVC were used as initial sites to graft a poly[poly(ethylene glycol) methylether methacrylate] [P(PEGMA)] brush. The synthesized PVC‐g‐P(PEGMA) graft copolymer served as an efficient additive for the hydrophilicity modification of the poly(vinylidene fluoride) (PVDF) membrane via a nonsolvent‐induced phase‐inversion technique. A larger pore size, higher porosity, and better connectivity were obtained for the modified PVDF membrane; this facilitated the permeability compared to the corresponding virgin PVDF membrane. In addition, the modified PVDF membrane showed a distinctively enhanced hydrophilicity and antifouling resistance, as suggested by the contact angle measurement and flux of bovine serum albumin solution tests, respectively. Accordingly, the PVC‐g‐P(PEGMA) graft copolymer was demonstrated as a successful additive for the hydrophilicity modification, and this study will likely open up new possibilities for the development of efficient amphiphilic PVC‐based copolymers for the excellent hydrophilicity modification of PVDF membranes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Controlled grafting from poly(vinylidene fluoride) microfiltration membranes via reverse atom transfer radical polymerization and antifouling properties

A reverse atom transfer radical polymerization (RATRP) with benzoyl peroxide (BPO)/CuCl/2,2-bipyridine (Bpy) was applied onto grafting of poly(methyl methacrylate) (PMMA) and poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA) from poly(vinylidene fluoride) (PVDF) microfiltration (MF) membrane surfaces, including the pore surfaces. The introduction of peroxide and hydroperoxide groups onto the PVDF membranes was achieved by ultraviolet (UV) irradiation in nitrogen, followed by air exposure. RATRP from UV pretreated hydrophobic PVDF membranes was then performed for attaching well-defined homopolymer. The chemical composition of the modified PVDF membrane surfaces was characterized by attenuated total reflectance (ATR) FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS). The surface and cross-section morphology of membranes were studied by scanning electron microscopy (SEM). The pore sizes of the pristine PVDF and the PMMA grafted PVDF membranes were measured using micro-image analysis and process software. With increase of graft concentration, the pore size of the modified membranes decreased and became uniform. Kinetic studies of homogeneous (in toluene solution) system revealed a linear increase in molecular weight with the reaction time and narrow molecular weight distribution, indicating that the chain growth from the membrane surface was a “controlled” or “living” grafting process. The introduction of the well-defined PMMA on the PVDF membrane gave rise to hydrophilicity. Protein adsorption and protein solution permeation experiments revealed that the UV pretreated hydrophobic PVDF membrane subjected to surface-initiated RATRP of methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) exhibited good antifouling property.     

Biomimetic surface modification on polyacrylonitrile-based asymmetric membranes via direct formation of phospholipid moieties

To improve the antifouling property and biocompatibility for polyacrylonitrile-based asymmetric membranes, phospholipid moieties were directly anchored on the poly(acrylonitrile-co-2-hydroxyethyl methacrylate) (PANCHEMA) membrane surface through the reaction of hydroxyl groups and 2-chloro-2-oxo-1,3,2-dioxaphospholane (COP) followed by the ring-opening of COP with trimethylamine. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and water contact angle measurement were employed to confirm the conducted surface modification. Water and protein solution filtration tests plus cell adhesion measurement were used to evaluate the antifouling property and the biocompatibility of the membranes. It was found that the content of the phospholipid moieties on the membrane surface, which can be mainly modulated by the content of reactive hydroxyl groups in PANCHEMA, has a great influence on the performances of the studied membranes. With the increase in the phospholipid moieties content at the modified membrane surface, the hydrophilicity and biocompatibility on the basis of water contact angle and macrophage adhesion can be improved significantly. Furthermore, the modified membranes show higher water and protein solution fluxes, and better flux recovery after cleaning than those of the original PANCHEMA membranes. All these results reveal that the antifouling property and biocompatibility of PANCHEMA membrane could be enhanced obviously by the introduction of phospholipid moieties on the membrane surface.     

Enhanced PVDF membrane performance via surface modification by functional polymer poly(N-isopropylacrylamide) to control protein adsorption and bacterial adhesion

The aim of this work is to prepare antifouling membrane with low-biofouling property by grafted functional polymer. Surface modification of poly(vinylidene fluoride) (PVDF) membrane was carried out via a modified and simple process by grafted poly(N-isopropylacrylamide) (PNIPAAm). The grafting density of PNIPAAm was significantly improved, up to 0.90 ± 0.38 mg/cm², thereby improving the properties and performance of the membrane. The chemical composition, thermal stability and surface morphology of pristine and modified membranes had been characterized by attenuated total reflectance fourier-transform infrared spectroscopy (ATR-FTIR), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM) and atomic force microscope (AFM), respectively. After modification, the hydrophilicity of PVDF membrane was dramatically enhanced due to incorporation of PNIPAAm chains. The results of protein adsorption, microfiltration experiments and bacterial adhesion test demonstrated that the modified membrane exhibited obvious thermo-sensitive property and good antifouling capability. The maximum of flux recovery ratio (FRR), 91.59%, was obtained for the modified membrane. It is evidently believed that protein foulants was removed easily from the modified membrane surface after water washing. In addition, bacterial adhesion test revealed that the attachment of Escherichia coli on the modified membrane was reduced by 75% compared to the original membrane.     

Surface immobilization of polymer brushes onto porous poly(vinylidene fluoride) membrane by electron beam to improve the hydrophilicity and fouling resistance

Poly(vinylidene fluoride) (PVDF) membrane was pre-irradiated by electron beam, and then poly(ethylene glycol) methyl ether methacrylate (PEGMA) was grafted onto the membrane surface in the aqueous solution. The degree of grafting was significantly influenced by the pH value of the reaction solution. The surface chemical changes were characterized by the Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS). Combining with the analysis of the nuclear magnetic resonance proton and carbon spectra (¹H NMR and ¹³C NMR), PEGMA was mainly grafted onto the membrane surface. Morphological changes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The porosity and bulk mean pore size changes were determined by a mercury porosimeter. The surface and bulk hydrophilicity were evaluated on the basis of static water contact angle, dynamic water contact angle and the dynamic adsorption process. Furthermore, relative high permeation fluxes of pure water and protein solution were obtained. All these results demonstrate that both hydrophilicity and fouling resistance of the PVDF membrane can be improved by the immobilization of hydrophilic comb-like polymer brushes on the membrane surface.     

Synthesis of well‐defined amphiphilic block copolymers via AGET ATRP used for hydrophilic modification of PVDF membrane

A well‐defined amphiphilic block copolymer consisting of a hydrophobic block poly(methyl methacrylate) (PMMA) and a hydrophilic block poly[N,N–2‐(dimethylamino) ethyl methacrylate] (PDMAEMA) was synthesized by activator generated by the electron transfer for atom transfer radical polymerization method (AGET ATRP). Kinetics study revealed a linear increase in the graph concentration of PMMA‐b‐PDMAEMA with the reaction time, indicating that the polymer chain growth was consistent with a controlled process. The gel permeation chromatography results indicated that the block copolymer had a narrow molecular weight distribution (Mw/Mn = 1.42) under the optimal reaction conditions. Then, poly(vinylidene fluoride) (PVDF)/PMMA‐b‐PDMAEMA blend membranes were prepared via the standard immersion precipitation phase inversion process, using the block copolymer as additive to improve the hydrophilicity of the PVDF membrane. The presence and dispersion of PMMA‐b‐PDMAEMA clearly affected the morphology and improved the hydrophilicity of the as‐synthesized blend membranes as compared to the pristine PVDF membranes. By incorporating 15 wt % of the block copolymer, the water contact angle of the resulting blend membranes decreased from pure PVDF membrane 98° to 76°. The blend membranes showed good stability in the 20 d pure‐water experiment. The bovine serum albumin (BSA) absorption experiment revealed a substantial antifouling property of the blend membranes in comparison with the pristine PVDF membrane. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42080.     

Modification of electrospun poly(vinylidene fluoride‐co‐hexafluoropropylene) membranes through the introduction of poly(ethylene glycol) dimethacrylate

For the modification of an electrospun poly (vinylidene fluoride‐co‐hexafluoropropylene) (PVDF–HFP) membrane for its potential use as an electrolyte or separator in lithium batteries, poly(ethylene glycol) dimethacrylate (PEGDMA) was introduced into a polymer solution for electrospinning. A post heat treatment of the as‐electrospun membrane at an elevated temperature was performed for PEGDMA polymerization, and this was verified by Fourier transform infrared spectroscopy. The results showed that no significant variations in the membrane morphology were detected when a small amount of PEGDMA (PVDF–HFP/PEGDMA mass ratio = 4/1) was incorporated. This electrospun membrane after heat treatment at 130°C for 2 h exhibited a significantly higher tensile strength (6.26 ± 0.22 MPa) than that of an electrospun PVDF–HFP membrane (3.28 ± 0.35 MPa) without PEGDMA. The porosity and liquid absorption of the electrospun PVDF–HFP/PEGDMA (4/1) membrane were 70.0 ± 1.6% and 267 ± 11%, respectively, lower than those of the electrospun PVDF–HFP membrane (76.5 ± 0.3% and 352 ± 15%) because of the introduction of PEGDMA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Study on the influence of reaction time on the structure and properties of the PVDF membrane modified through the method of atom transfer radical polymerization

A thermo‐responsive membrane, poly(vinylidene fluoride) (PVDF‐g‐PNIPAAm), was successfully prepared from PVDF membrane through surface‐initiated atom transfer radical polymerization (ATRP) of a thermo‐responsive monomer, N‐isopropyl acrylamide (NIPAAm). The influence of the reaction time on ATRP was studied in detail. The grafting membrane was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS). The results showed that NIPAAm was successfully grafted on the PVDF membrane, the membrane pores became smaller and the reaction time of 36 h was in favor of surface‐initiated ATRP. The thermal stability of PVDF membrane and PVDF‐g‐PNIPAAm membranes was characterized by differential scanning calorimetry (DSC). Contact angles of membrane surface, water penetration and protein solution permeation were tested. Water contact angles of PVDF membrane reduced after the surface grafting of NIPAAm, which illuminated that the hydrophilicity of the grafted membrane was improved. The PVDF‐g‐PNIPAAm membranes exhibited good thermo‐responsive permeability and antifouling property. POLYM. ENG. SCI., 54:1013–1018, 2014. © 2013 Society of Plastics Engineers     

Surface functionalization of poly(vinylidene fluoride) membrane by radiation-induced emulsion polymerization of hydroxyethyl acrylates in an aqueous medium

Decades ago, surface modification of poly(vinylidene fluoride) (PVDF) membrane became an essential subject. The change is mainly to enhance the hydrophilicity properties of the membrane in order to increase the adsorption capacity, thus making as a novel adsorbent. This study aims to used radiation-induced polymerization and compares the final properties of PVDF grafted hydroxyethyl acrylates (HEA) prepare by two different approaches. The PVDF-grafted-HEA has achieved either direct polymerization or emulsion polymerization. Tween-20 has been used as a surfactant in emulsion polymerization. The final PVDF-grafted poly-HEA was analyzed using several different instruments to observe the changes in terms of morphological structure, topography properties, thermal stability, mechanical strength, and hydrophilicity. Significant differences were seen in morphology and contact angles properties. By emulsion polymerization, poly-HEA grafted in the shape of micelles compare to by direct polymerization shown a thin homogenous layer. Thus, the surface roughness of PVDF by emulsion is higher lead to higher contact angles. Even though both approaches demonstrate significant changes in the physicochemical properties of the PVDF membrane, it is revealed that radiation-induced direct polymerization approaches could achieve a hydrophilic PVDF-grafted HEA.     

Ag3PO4改性PVDF超滤膜的结构与性能

将不同量Ag₃PO₄均匀地分散在聚偏氟乙烯(PVDF)铸膜液中, 利用相转化法制备了改性PVDF膜, 通过扫描电镜(SEM)、接触角测定、过滤实验和污染性测试等研究了其微结构、分离性和耐污染性等, 并考察了膜污染后的清洗效果。结果表明, 添加Ag₃PO₄ 的PVDF膜具有不同的微结构与性能, 当添加1% 的Ag₃PO₄时, 膜皮层变薄、微孔数增多, 并呈现出最优化的水通量、亲水性、力学性、抗污染能力和截留率等。采用太阳光-水清洗能使改性膜的通量恢复率达到85%以上。     

Surface modification of polyamide and poly(vinylidene fluoride) membranes

Experimental results from the gas‐plasma treatment and electron‐beam irradiation of polyamide (PA) and poly(vinylidene fluoride) (PVDF) membranes to improve their wettability and to evaluate protein adsorption at their surface are presented. The wettability of the membrane surface was determined by contact angle measurements; the analysis of the surface composition was performed by X‐ray photoelectron spectroscopy (XPS). We observed that a reduction in the water contact angle was not always indicative of a reduction in the protein adsorption and, furthermore, that a charge at the surface of the modified membrane seemed to be a major factor in the protein adsorption process. Furthermore, the XPS results shed some light on the modification mechanism of PVDF and PA by electron‐beam irradiation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

PVDF-TiO2复合中空纤维膜的制备与表征

将纳米二氧化钛(TiO₂)粒子与4类制膜添加剂复配处理,采用相转化法制备聚偏氟乙烯(PVDF)-TiO₂复合中空纤维膜,讨论了纳米TiO₂粒子对复合膜结构和性能的影响。通过扫描电子显微镜、X射线衍射、能谱分析、热重分析、拉伸试验、接触角测定和超滤实验分别表征了复合膜的微观孔结构、晶相结构和复合均匀性、热稳定性、机械性能、亲水性、超滤性能以及抗污染性能。结果表明：通过添加TiO₂粒子复配添加剂,复合膜的性能得到有效改善。复配添加剂中w(TiO₂)为2%(占PVDF固含量的质量分数)时,纯水通量由348 L/(m²·h)提高至377 L/(m²·h),牛血清蛋白截留率由68%提高至90%,断裂强度和抗污染性能提高,复合膜综合性能优异。     

Second modification of a polyamide membrane surface

The aim of this study was to develop the water flux and antifouling properties of a polyamide (PA) nanofiltration membrane. A nascent PA membrane was prepared with an interfacial polymerization technique and modified with 2,5‐diaminobenzene sulfonic acid (2,5‐DABSA) as a second modification. The effects of the 2,5‐DABSA monomer concentration and the modification time on the membrane performance were investigated. The chemical structure, morphology, roughness, hydrophilicity, molecular weight cutoff, and antifouling properties of the membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force spectroscopy, contact angle measurement, poly(ethylene glycol) tracers, and cetyl trimethyl ammonium bromide filtration, respectively. The PA membrane with optimized performance was shown to have a greater than 44% higher water permeate flux with a change in the salt rejection in the order RNa₂SO₄ > RCaCl₂ > RNaCl to RNa₂SO₄ > RNaCl > RCaCl₂. The improvement of the hydrophilicity led to excellent antifouling properties in the new PA membranes and illustrated a promising and simple method for the fabrication of high‐performance PA membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43583.     

Poly(vinylidene fluoride) hollow‐fiber membranes containing silver/graphene oxide dope with excellent filtration performance

In this study, an antifouling poly(vinylidene fluoride) (PVDF) hollow‐fiber membrane was fabricated by blending with silver‐loaded graphene oxide via phase inversion through a dry‐jet, wet‐spinning technique. The presence of graphene oxide endowed the blended membrane with a high antifouling ability for organic fouling. The permeation fluxes of the blended membrane was 3.3 and 2.9 times higher than those of a pristine PVDF membrane for filtering feed water containing protein and normal organic matter, respectively. On the other hand, the presence of silver improved the antibiofouling capability of the blended membrane. For the treatment of Escherichia coli suspension, the permeation flux of the blended membranes was 8.2 times as high as that of the pristine PVDF membrane. Additionally, the presented blended membrane improved the hydrophilicity and mechanical strength compared to those of the pristine PVDF membrane, with the water contact angle decreasing from 86.1 to 62.5° and the tensile strength increasing from 1.94 to 2.13 MPa. This study opens an avenue for the fabrication of membranes with high permeabilities and antifouling abilities through the blending of graphene‐based materials for water treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44713.     

Synthesis and characterization of low content of different SiO2 materials composite poly (vinylidene fluoride) ultrafiltration membranes

A comparison of the morphology and performance of virgin poly (vinylidene fluoride) (PVDF) ultrafiltration (UF) membrane, and PVDF-composite membranes with low content of two different SiO₂ (N-SiO₂ and M-SiO₂ particles) was carried out. Cross-sectional area and surface morphology of the membranes were observed by scanning electron microscopy and atomic force microscopy. Surface hydrophilicity of the porous membranes was determined through the measurement of a contact angle. Performance tests were conducted on the composite membranes through water flux and bovine serum albumin (BSA) retention. Average pore size and surface porosity were calculated based on the permeate flux. Thermal stability and mechanical stability were determined by thermogravimetric analysis and tensile stress tests. The results indicate that N-SiO₂/PVDF (P-N) membranes possessed larger average pore size and porosity, which led to higher water flux and a slight decline in BSA retention. On the other hand, M-SiO₂/PVDF (P-M) membranes had better mechanical stability and anti-fouling performance with enhanced membrane hydrophilicity and decreased membrane surface roughness. Both of the P-N and P-M membranes exhibited typical asymmetric morphology and improved thermal stability.     

Fabrication and characterization of high flux poly(vinylidene fluoride) electrospun nanofibrous membrane using amphiphilic polyethylene-block-poly(ethylene glycol) copolymer

Electrospun nanofiber membranes (ENM) made of polymers such as polysulfone and poly(vinylidene fluoride) (PVDF) have a much higher contact angle (CA) and also more hydrophobic when compared to the virgin polymers. For water treatment applications, membranes with hydrophilic nature are highly desirable in order to achieve high flux and less fouling potentials. Hence, in the present study, highly hydrophilic electrospun nanofiber membranes (ENMs) were prepared by blending PVDF polymer with amphiphilic polyethylene-block-poly (ethylene glycol) (PE-b-PEG) copolymer. Resulting amphiphilic ENMs were highly porous (77%–92%) and the breaking elongation of 140% with a young's modulus of 2.55 MPa was observed. When compared with the control PVDF membrane, PE-b-PEG blended ENMs revealed higher water permeation flux owing to the enrichment of the hydrophilic PEG segments at the membrane surface, which was confirmed by using X-ray photoelectric spectroscopy and Energy-dispersive spectroscopy measurements. When compared to the phase inversion process (CA of 97.3°) blended ENM had CA of 0°, which indicates that besides hydrophilic block copolymer segments, the nature of membrane formation also contributes its role in influencing the hydrophilicity of the membrane. This improved hydrophilicity in combination with larger pore sizes of the PVDF/ PE-b-PEG membranes have contributed to enhancement of pure water flux, protein solution permeability and water flux recovery, which can be applied potentially for water treatment applications.     

Protein immobilization onto poly (vinylidene fluoride) microporous membranes activated by the atmospheric pressure low temperature plasma

Hydrophobic poly (vinylidene fluoride) (PVDF) membrane surface was treated with atmospheric pressure low temperature plasma and investigated physical and chemical surface characterization. The contact angle of water on the exposed membrane surface was reduced with increasing of the treatment voltage and time, so indicates that the treatments can modify the PVDF membrane surface from hydrophobic to hydrophilic. In order to analyze the phenomenon in detail, the progress of defluorination including dehydrofluorination and oxidation reactions onto the surface was examined by X-ray photoelectron spectroscopy (XPS), and revealed the most effective treatment condition. The degree of grafting used acrylic acid monomer onto the surface has influenced with monomer concentration, reaction temperature and reaction time. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to study the surface morphology. The membrane surfaces conjugated bovine serum albumin (BSA) as a protein were surely detected the nitrogen element contained with BSA.     

Structural and performance properties of UV-assisted TiO2 deposited nano-composite PVDF/SPES membranes

In this research, the surface of poly (vinylidene fluoride) (PVDF)/sulfonated polyethersulfone (SPES) blend membrane prepared via immersion precipitation was modified by depositing of TiO₂ nano-particles followed by UV irradiation to activate their photocatalytic property. The membranes were characterized by FTIR, SEM, AFM, contact angle, dead end filtration (pure water flux and BSA solution flux), antifouling analysis and antibacterial activity. The FTIR spectrum confirmed the presence of OH functional groups on the PVDF/SPES membrane structure, which was the key factor for deposition, and self-assembly of TiO₂ nanoparticles on the membrane surface. The SEM and AFM images indicated that the TiO₂ nanoparticles were deposited on the PVDF/SPES membrane. The contact angle measurements showed that the hydrophilicity of PVDF/SPES membrane was strongly improved by TiO₂ deposition and UV irradiation. The filtration results indicated that the initial flux of TiO₂ deposited PVDF/SPES membranes was lower than the initial flux of neat PVDF/SPES membrane. However, the former membranes showed lower flux decline compared to the neat PVDF/SPES membrane. The BSA rejection of modified membranes was improved. The fouling analysis demonstrated that the TiO₂ deposited PVDF/SPES membranes showed the fewer tendencies to fouling. The results of antibacterial study showed that the UV irradiated TiO₂ deposited PVDF/SPES membranes possess high antibacterial property.