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1.
Membrane bioreactor (MBR) as a hybrid technology for wastewater treatment is becoming more popular for wastewater treatment. However, membrane fouling has hindered the widespread application of MBRs. Many efforts have been done for fouling mitigation. In this study, high flux and antifouling microfiltration membranes with unique surface structure, high surface porosity, and permeability were prepared by electrospinning technique. Initially, the optimum thickness of electrospun polyacrylonitrile (PAN) membranes was determined and then, electrospun PAN membrane at optimum thickness were prepared by embedding para‐aminobenzoate alumoxane (PABA) nanoparticles at different concentrations. The effect of PABA nanoparticles on membrane performance was investigated. To investigate the characterization of the prepared membranes Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X‐ray spectroscopy, and water contact angle measurement were employed. The flux recovery ratio results revealed that the antifouling properties of the electrospun PAN membrane were enhanced by modification. The 3 wt % electrospun PABA embedded PAN had the best permeability, hydrophilicity, and antifouling properties among the fabricated membranes and showed remarkable reusability during filtration. The results obtained suggested that the high flux and antifouling electrospun PAN membranes embedded PABA nanoparticles could be used as MBR membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45738.  相似文献   

2.
Polyethylene glycol-grafted nanodiamond (ND-PEG) was synthesized from pristine detonation NDs and utilized to prepare novel cellulose acetate/polyethylene glycol-grafted nanodiamond(CA/ND-PEG)nanocomposite membranes. Due to unique thermal, mechanical, and antibacterial properties and very easy cleaning of fouled ND-embedded CA nanocomposite membranes, we tried to investigate the performance of CA/ND-PEG membrane for humic acid (HA) removal from contaminated water. Surface functionalization was confirmed by Fourier transform infrared spectroscopy and thermogravimetry analysis. Pristine and functionalized ND with different concentration was added in the casting solution containing CA. The prepared membranes were characterized using contact angle, mechanical strength, scanning electron microscopy (SEM), transmission electron microscopy, and permeation tests. SEM micrographs of the surface of the membranes depicted the increase in the number of pores by the addition of ND and especially ND-PEG into polymer matrix. The results indicated that the nanocomposite membrane with 0.5 wt% ND-PEG exhibited excellent hydrophilicity, mechanical properties, permeability, high rejection, high abrasion resistance, and good anti-fouling performance. The HA adsorption on the membrane surface decreased from 2.85 to 2.15 mg cm?2 when the ND-PEG content increased from 0 to 0.5 wt%. Most importantly, the HA filtration experiments revealed that the incorporation of ND and especially ND-PEG particles reduced membrane irreversible fouling, dramatically. Meanwhile, the analysis of the fouling mechanism based on Hermia’s model revealed that cake formation is a prevailing mechanism for all membranes.  相似文献   

3.
In this study, a commercial polyamide nanofiltration membrane was modified by a combination of poly(ethylene glycol) diacrylate (PEGDA) in situ polymerization and silica (SiO2) nanoparticles. The PEGDA layer was polymerized on the surface of the membranes alone or mixed with SiO2 nanoparticle. The surface modification influence on the water flux, salt rejection, and antifouling behavior was investigated. The effects of the nanoparticles and PEGDAylation on the membrane properties were characterized by Fourier transform infrared spectroscopy, contact angle measurement, and scanning electron microscopy analyses. The membranes that were in contact with 30 wt % PEGDA and then treated with ultraviolet light for 5 min had a better water flux than the unmodified membrane. The fouling resistance of the membranes to a foulant solution containing bovine serum albumin, humic acid, and sodium sulfate were studied, and the results show that the membrane with 30 wt % PEGDA had better antifouling properties. After the weight percentage of PEGDA for the prepolymerization solution was optimized (30 wt % was the best), the SiO2 nanoparticle concentration in the prepolymerization matrix was optimized. The presence of SiO2 nanoparticles in the PEGDA layer increased the membrane flux. The maximum water flux and good antifouling properties were obtained for 0.5 wt % SiO2 nanoparticles in a 30 wt % PEGDA layer. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43793.  相似文献   

4.
Sulfonated poly(amide‐imide) (SPAI) copolymer was synthesized, characterized, and blended into poly(ether sulfone) (PES)/dimethylacetamide casting solutions to prepare ultrafiltration membranes. Different weight ratios of the copolymer (0–10 wt %) were mixed in the PES casting solution. The analyses of contact angle and attenuated total reflection‐Fourier transform infrared spectra were used to study hydrophilicity and physicochemical properties of the membrane surface, respectively. The membranes were further characterized by scanning electron microscopy images, ultrafiltration performance, and fouling analyses. The outcomes showed that addition of the SPAI in the PES matrix improved considerably the membranes hydrophilicity. Moreover, with increasing SPAI concentration, the porosity, flux recovery ratio, and pure water permeability of the modified membranes were improved. The pure water flux was increased from 3.6 to 12.4 kg/m2 h by increasing 2 wt % SPAI. The antifouling property of the modified PES membranes against bovine serum albumin, tested by a dead‐end filtration setup revealed that bovine serum albumin rejection of the obtained membrane was also enhanced and the antifouling properties of the blending membranes were improved. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46477.  相似文献   

5.
A small molecular-weight cut-off (MWCO) of 6000 Da poly(m-phenylene isophthalamide) (PMIA) embedded zinc oxide (ZnO) hybrid ultrafiltration (UF) membrane was synthesized via nonsolvent-induced phase separation (NIPS). Tests of field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), thermal gravimetric analyzer (TGA), Fourier transform infrared (FTIR), capillary flow porometer (CPF), mechanical test, and pure water flux (PWF) for characterization of membranes were carried out. The EDX, FTIR, and TGA indicated the presence of ZnO in the polymer matrix. The hybrid membranes showed enhanced pore density, PWF by the presence of the particles. The contact angle and water flux of modified membrane with 0.03 wt % of nano-ZnO were 47.7° and 52.58 L·m−2·h−1 compared to 71.6° and 36.27 L·m−2·h−1 respectively; Compared with the hydrophobic membrane, the PMIA membrane, with hydrophilicity, is supposed to exhibit good antifouling properties. Furthermore, the thermal stability and mechanical properties of the modified membranes were increased. Finally, the hybrid membrane was used in treating papermaking white wastewater and exhibited good separation and high water flux. The great properties of the ultrafiltration PMIA membranes indicate their potential for excellent performance in industrial applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47583.  相似文献   

6.
In forward osmosis, internal concentration polarization is related to the properties (e.g., hydrophilicity, porosity, structural resistant) of membrane support layer. In this work, polyethylene glycol with a low molecular weight of 400 Da was introduced as a support layer additive during the fabrication of thin-film polyamide-polysulfone composite forward osmosis membranes. The forward osmosis performances including water flux and reverse salt flux of the membranes were tested in the mode of AL-FS where the membrane active layer faced toward feed solution. Results showed that the addition of polyethylene glycol would reduce internal concentration polarization and improve membrane performance in forward osmosis by means of enhancing membrane hydrophilicity and changing pore morphologies of membrane support layer. The membrane prepared with 6 wt.% polyethylene glycol was found to exhibit the highest water flux of 47.4 Lm?2h?1 with a reverse salt flux of 7.6 gm?2h?1 when using DI water and 2.0 M NaCl as the feed and the draw solution, respectively, indicating an optimal polyethylene glycol dosage of 6 wt.% in this work.  相似文献   

7.
Membranes were fabricated with high-density polyethylene(HDPE) and ethylene vinyl acetate(EVA) blend through thermally induced phase separation and were then used for vacuum membrane distillation(VMD).The membranes were supported by nonwoven polyester fabric with a special cellular structure. Different membrane samples were obtained by adjusting the polymer concentration, HDPE/EVA weight ratio, and coagulation bath temperature. The membranes were characterized by scanning electron microscopy(SEM) analysis, contact angle test, and evaluation of porosity and pore size distribution. A series of VMD tests were conducted using aqueous NaCl solution(0.5 mol·L~(-1)) at a feed temperature of 65 ℃ and permeate side absolute pressure of 3 kPa. The membranes showed excellent performance in water permeation flux, salt rejection, and long-term stability. The HDPE/EVA co-blending membranes exhibited the largest permeation flux of 23.87 kg·m~(-2)·h~(-1) and benign salt rejection of ≥99.9%.  相似文献   

8.
This article discusses the methods of interface modification of composites based on raw wood flakes and high‐density polyethylene (HDPE) and the effects of these modifications on composite properties. An HDPE matrix was modified by a reaction with maleic anhydride (MA) in a twin‐screw extruder and then compounded with wood flakes to produce wood–polyethylene composites. Wood flakes were modified by a reaction with a silane coupling agent in an aqueous medium before being compounded with HDPE to produce silane‐modified WPCs. Differential scanning calorimetry and Fourier transform infrared spectroscopy data provide evidence for the existence of a polyethylene (PE)–silane‐grafted wood structure, which acts as a compatibilizer for wood flakes and PE. The results of MA‐modified composites indicate that some maleated HDPE is reacting with wood through esterification to form a compatibilizer for wood flakes and HDPE. Significant improvements in tensile strength, ductility, and Izod impact strength were obtained. Scanning electron micrographs provide evidence for strong interactions between the wood flakes and the matrix agent. The results indicate that 1–2 wt % MA modification on HDPE and 1–3 wt % silane treatment on wood flakes provide WPCs with the optimum properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2505–2521, 2002  相似文献   

9.
In this work, a novel approach to improve the antifouling properties of membrane surfaces was developed. First, a polydopamine layer was attached onto the surface of an ultrahigh molecular weight polyethylene/fabric composite microporous membrane based on dopamine self‐polymerization and adhesive behavior. Then, methoxy polyethylene glycol amine was covalently bonded with the polydopamine layer via a Schiff base reaction. The physicochemical properties of the modified composite membrane surface were investigated, and the results indicated this modification could effectively enhance the membrane surface hydrophilicity. Furthermore, the protein fouling resistance of both dopamine‐coated and methoxy polyethylene glycol amine immobilized composite membranes was evaluated. It was found that a dopamine coating cannot obviously enhance the membrane antifouling properties due to its strong bioadhesion behavior. However, the antifouling properties of the composite membranes were significantly improved after being immobilized with a methoxy polyethylene glycol amine layer. Consequently, a layer‐by‐layer modified composite membrane with excellent antifouling property was obtained. The pure water flux and flux recovery ratio of the resultant membrane were 764 L m?2 h?1 and 83%, respectively. The aim of this paper was to provide an effective approach to optimizing the separation efficiency and antifouling performance of the ultrahigh molecular weight polyethylene/fabric composite membrane. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46428.  相似文献   

10.
Herein, phase inversion poly(vinylidene fluoride)/poly(methyl methacrylate) (PVDF/PMMA) microporous membranes were prepared at various PMMA concentration by immersion precipitation method. Increment in the PMMA concentration has a significant influence in the PVDF membrane crystallinity, which is studied by differential scanning calorimeter, X-ray diffractometer, and small-angle X-ray scattering analyses. Properties such as membrane bulk structure, porosity, hydrophilicity, mechanical stability, and water flux vary in terms of PMMA concentration. Porosity is increased, and tensile strength decreased when PMMA concentration is beyond 30 wt %. Thermodynamic instability during the liquid to solid phase separation and variation in the crystallinity has an intense effect on these membrane properties. Then, 70/30 blend membrane selected as optimum composition owing to the high porosity and pure water flux compared to other compositions. This membrane is modified with a composite filler derived from the graphene oxide and titanate crosslinked by chitosan. The antibacterial, antifouling, and bovine serum albumin separation studies reveal that the developed nanocomposite membrane is a potential candidate for the separation application. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48677.  相似文献   

11.
This research discusses the mechanical behavior and the microstructure of high-density polyethylene (HDPE)-based composites, manufactured using the melt-mixing and thermal-pressing techniques, where HDPE is mixed with various percentages of either bulk lead monoxide (bulk PbO) or PbO nanoparticles (PbO-NPs) acting as fillers. The scanning electron microscope and the field emission transmission electron microscope were utilized to identify the morphology of polymeric composites. Both showed the proper dispersion of PbO in the HDPE matrix without substantial agglomerations. The effect of PbO on the thermal behavior of the HDPE was studied using the thermogravimetric analysis. Tensile tests were implemented to find out how the mechanical characteristics of the composites were affected. Yield stress, % elongation at break, stiffness, tensile energy (toughness), ultimate tensile strength, and ultimate tensile strain were elucidated in this work. The values of stiffness, ultimate tensile strength, and yield stress increased by increasing either the bulk PbO or PbO-NPs' loading up to 40.0 wt % with reference to the hosting matrix. The values of ultimate tensile strain, tensile energy, and % elongation at break of the assembled composites diminished dramatically by increasing the filler's content from 10.0 to 50.0 wt %. Besides, composites with PbO-NPs as a filler were identified as having higher mechanical characteristics than those with bulk PbO for the same wt %. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47812.  相似文献   

12.
Polyvinylidene fluoride (PVDF) and polyacrylonitrile (PAN) ultrafiltration (UF) membranes are widely used in drinking water and wastewater applications. These membranes are prone to fouling and membrane efficiency decreases with time under constant operation. Significant improvements/modifications are necessary to apply these polymers as sustainable membrane materials. In this study, PVDF and PAN UF membranes were modified through incorporation of nanoparticles (NPs) namely SiO2 and TiO2. PVDF and PAN UF membranes were prepared by phase inversion method from polymer solutions having dispersed SiO2 and TiO2 NPs in it. Membrane surface hydrophilicity, charge, roughness, and morphology were studied. Equilibrium water content and molecular weight cut-off of the membranes were also measured. Addition of NPs increased membrane surface hydrophilicity, equilibrium water content, and surface potential. NPs modified membranes exhibited better membrane flux (35–79% higher) and antifouling properties (flux recovery ratio values 28–41% higher) than the virgin membranes.  相似文献   

13.
A novel polycarbonate (PC) membrane was modified with titanium dioxide via nonsolvent-induced phase separation method to improve its hydrophilicity and antifouling properties in a submerged membrane system for the removal of humic acid (HA) both with and without polyaluminum chloride (PAC) coagulant. The effect of TiO2 additive on the morphology and performance of the nanocomposite membranes was studied by atomic force microscopy, field emission scanning electron microscopy, energy dispersive X-ray, mechanical properties, water contact angle, porosity, pure water flux, rejection tests, and antifouling parameters. The obtained results revealed that a higher critical flux was achieved by the PC/TiO2 nanocomposite membrane. The flux recovery ratio of the neat PC membrane increased with the addition of TiO2 nanoparticles and without PAC coagulant. HA removal for the PC nanocomposite membrane was higher than that of the neat PC membrane with and without PAC coagulant.  相似文献   

14.
A non-solvent induced phase separation (NIPS) process was used to fabricate a series of sulfonated polyethersulfone (SPES) membranes blending with different concentrations of SBA-15-g-PSPA with the applications in the ultrafiltration (UF) process. SBA-15 was modified with 3-methacrylate-propyltrimethoxysilane (MPS) to form SBA-15-g-MPS. It was further modified with the charge tailorable polymer chains by reacting with 3-sulfopropyl methacrylate potassium salt. The nanoparticles were uniformly dispersed and finger-like channels were developed within the membrane. The adding of surface modified SBA-15-g-PSPA nanoparticles has significantly improved membrane water permeability, hydrophilicity, and antifouling properties. The pure water fluxes of the composite SPES membranes were significantly higher than the pristine SPES membrane. For the membrane containing 5% (mass) of SBA-15-g-PSPA (MSSPA5), the pure water flux was increased dramatically to 402.15 L·m-2·h-1, which is ~1.5 times that of MSSPA0 (268.0 L·m-2·h-1). The high flux rate was achieved with 3% (mass) of SBA-15 nanoparticles with retained high rejection ratio 98% for natural organic matter. The results indicate that the fashioned composite membrane comprising SBA-15-g-PSPA nanoparticles have a promising future in ultrafiltration applications.  相似文献   

15.
Poly(acrylonitrile‐coN ‐vinyl‐2‐pyrrolidone)s (PANCNVPs) show excellent biocompatibility. In this work, PANCNVPs with different contents of N‐vinyl‐2‐pyrrolidone (NVP) were fabricated into asymmetric membranes by the phase inversion method. The surface chemical composition of the resultant membranes was determined by Fourier transform infrared spectroscopy–attenuated total reflection. Field emission scanning electron microscopy was used to examine the surface and cross section morphologies of the membranes. It was found that the morphologies hardly change with the increase of NVP content in PANCNVP, while the deionized water flux increases remarkably and the bovine serum albumin (BSA) retention decreases slightly. Experiment of dynamic BSA solution filtration was carried out to evaluate the antifouling properties of the studied membranes. The relative flux reduction of PANCNVP membrane containing 30.9 wt % of NVP is 25.9%, which is far smaller than that of the polyacrylonitrile membrane (68.8%). Results deduce that this improvement comes from the excellent biocompatibility of NVP moieties instead of the hydrophilicity change, because the water contact angles of these membranes fluctuate between 60 and 70°. Results from the membranes using poly(N‐vinyl‐2‐pyrrolidone) (PVP) as an additive confirm that, to a certain extent, the PANCNVP membranes show the advantages of antifouling compared with the polyacrylonitrile/PVP blending membrane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4577–4583, 2006  相似文献   

16.
Cellulose acetate (CA) nanocomposite ultrafiltration membranes are fabricated with copper oxide (CuO) nanoparticles with the aim of improving efficient protein separation and antifouling performance. CuO nanoparticles are synthesized from cupric nitrate using a wet precipitation method and characterized by FTIR and XRD. CA/CuO nanocomposite membranes fabricated using 0.5, 1.0, and 1.5 wt% of CuO nanoparticles individually by simple phase inversion technique. The CA nanocomposite membrane with 0.5 wt% of hydrophilic CuO exhibited enhanced PWF of 118.6 Lm−2 h−1 due to the improvement in porosity and water uptake. This is in good agreement with the enhanced hydrophilicity of the CA/CuO nanocomposite membranes results observed in surface contact angle and morphological investigations. Further, 95.5% of BSA separation and 94.7% of flux recovery ratio (FRR) indicates its superior antifouling potential caused due to the presence of the hydration layer at the CA/CuO membrane surface. Among all the fabricated membranes, the CA-0.5 nanocomposite membrane with 0.5 wt% of CuO exhibited superiorly improved hydrophilicity, water permeation, BSA separation, and antifouling performance indicates its potential use in water and wastewater treatment applications.  相似文献   

17.
Poly(vinylidene chloride‐co‐vinyl chloride) (P(VDC‐co‐VC) membranes were prepared by non‐solvent‐induced phase separation and adjusted by adding water‐soluble polyethylene glycol (PEG) and water‐insoluble silicon dioxide (SiO2) hydrophilic nanoparticles. The structure of pores and antifouling performance were investigated to illustrate the effect of these nanoparticles. The cross section of the P(VDC‐co‐VC) membrane exhibited more macropores and the typical finger‐like pores turned into more vertically interconnected ones with increasing PEG content, while the number and size of finger‐like pores became less with increasing SiO2 content. Considering the filtration and antifouling experiments, the presence of hydrophilic PEG and SiO2 nanoparticles in the P(VDC‐co‐VC) polymer matrix improved the membrane performance in terms of high flux, high BSA rejection ratio, and fouling resistance.  相似文献   

18.
In order to develop excellent comprehensive mechanical strength and stability in high-density polyethylene (HDPE)/wood fiber (WF) composites, polyamide 6 (PA 6), and WF modified by environmental-friendly high temperature vapor (WF-HTV) were utilized to reinforce the compound system. The properties relating to interfacial compatibility in HDPE/WF-HTV composites were characterized and evaluated by electron universal mechanical instrument, water absorption testing, thermogravimetry, scanning electron microscope, Fourier transfer infrared spectroscopy, and differential scanning calorimetry. The results reveal that this novel compounding system can engender a synergistic effect for interfacial interactions among PA 6, HDPE, and WF-HTV only when the ratio of HDPE to PA 6 is at an optimum level (HDPE:PA 6 = 6:4). The maximum values for flexural strength, modulus, tensile strength, and impact strength can be increased by 82.05, 64.08, 93.47, and 120.45%, respectively, compared with those of HDPE/WF-HTV composites. Additionally, maximum decomposition temperatures for the first and second thermal degradation stages can be increased by 7.17and 8.99 °C, respectively. Water absorption can be effectively controlled at a relatively low level (approximately 1.50%). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47984.  相似文献   

19.
In this study polysulfone membranes with antifouling and hydrophilic properties were synthesized using poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (AMPS) as an additive for the first time. Different wt % of AMPS was used to prepare polysulfone membranes by phase inversion method. The role of AMPS on the porosity, pore size distribution, hydrophilicity, and antifouling nature was investigated and analyzed in detail. Characterization techniques like field emission scanning electron microscope, atomic force microscopy, and imageJ software were used to characterize the morphology of prepared membranes. There is positive effect of the additive addition on all the membrane parameters like Pure water flux [101.76 L/(m2 h)] (MR0) to 464.06 L/(m2 h) (MR4)], hydraulic permeability [0.65 (MR0) to 2.01 (MR4)], equilibrium water content [21.74 (MR0) to 71.45 (MR4)], and porosity [0.024 (MR0) to 0.58 (MR4)]. Response surface methodology was used for the optimization of bovine serum albumin (BSA) flux and rejection. The results of the morphological as well as permeation studies depicted that permeate flux and antifouling nature were increased with the amount of AMPS present in the membrane matrix. The antifouling study of the prepared membranes was undertaken by using BSA solution of 1000 mg/L. Positive results were seen with the increase in amount of AMPS, since, the total membrane resistance has been decreased from 0.95 (MR0) to 0.74 (MR4). Separation of humic acid from aqueous medium was also performed with the best performing membrane (MR4, having the highest amount of AMPS). Separation efficiency of 100% and 94% were obtained using 10 mg/L and 50 mg/L of HA, respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45290.  相似文献   

20.
Nano‐ZnO/high‐density polyethylene (HDPE) composite films were prepared via melt blending and a hot compression‐molding process. The properties, including ultraviolet absorption, mechanical and antibacterial properties of the films, and plasticizing behavior of the composites, were investigated. The results show that the absorbance in the ultraviolet region of the HDPE films was enhanced after the addition of modified nano‐ZnO to the HDPE matrix. Also, we found that improvement in the HDPE films of the tensile strength and elongation at break was achieved by the incorporation of modified ZnO nanoparticles up to 0.5 wt % in contrast with the original nano‐ZnO/HDPE composite films. Antibacterial testing was carried out via plate counting, and the results indicate that the HDPE films doped with modified ZnO nanoparticles showed favorable antibacterial activity, especially for Staphylococcus aureus. However, the low doped content of modified nano‐ZnO in the HDPE matrix made the balance torque of the composites increase slightly. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

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