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Ahmad Rahimpour - One of the best experts on this subject based on the ideXlab platform.
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tio2 entrapped nano composite pvdf spes membranes preparation characterization antifouling and antibacterial properties
Desalination, 2011Co-Authors: Ahmad Rahimpour, Mohsen Jahanshahi, Babak Rajaeian, Mostafa RahimnejadAbstract:Abstract In the current study, poly (vinylidene fluoride) (PVDF)/sulfonated polyethersulfone (SPES) blend membrane was modified using TiO2 nano-particles. Firstly, sulfonation of polyethersulfone (PES) was carried out, then PVDF/SPES blend membranes were prepared with and without TiO2 nano-particles in the Casting Solution using phase inversion induced by immersion precipitation technique. Polyvinylpirrolidone (PVP) with the concentration of 4 wt.% was added in the Casting Solution as pore former. The morphological studies were investigated using SEM, AFM, XRD, FTIR and contact angle goniometry. They showed that the average sizes of membrane pores in surface and sub-layer were reduced with addition of TiO2 nano particles in the Casting Solution. The presence of TiO2 nano-particles in the membrane structure was confirmed by XRD, FTIR and EDX analyses. The contact angle measurements demonstrated that the hydrophilicity of modified membranes was enhanced by addition of TiO2 in the Casting Solution. The experimental results demonstrated that the initial flux of TiO2 entrapped PVDF/SPES membranes was lower than the initial flux of neat PVDF/SPES membrane. The antifouling properties of membranes were improved by changing the membrane surface from hydrophobic to hydrophilic after TiO2 addition in the Casting Solution. Finally, neat and 4% TiO2 modified PVDF/SPES membranes were tested to possess the dramatic photo-bactericidal effect on Escherichia coli (E. coli).
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improvement of performance and surface properties of nano porous polyethersulfone pes membrane using hydrophilic monomers as additives in the Casting Solution
Journal of Membrane Science, 2010Co-Authors: Ahmad Rahimpour, S S MadaeniAbstract:Abstract The effects of hydrophilic monomers e.g. acrylic acid (AA) and 2-hydroxyethylmethacrylate (HEMA) on the morphology and performance of polyethersulfone (PES) membrane were investigated. The membranes were fabricated from a Casting Solution of PES, dimethylacetamide (DMAC), polyvinylpyrrolidone (PVP) and AA or HEMA via phase inversion induced by immersion precipitation. The mixture of water (80 vol.%) and 2-propanole (IPA, 20 vol.%) was employed as gelation media. The prepared membranes were characterized using ATR-FTIR, SEM, AFM, contact angle, viscosity measurements, ultrafiltration performance and fouling analysis. The hydrophilicity of PES membrane was improved after addition of AA and HEMA in the Casting Solution. The morphological studies (SEM and AFM) showed that the average sizes of membrane pores in surface and sub-layer were reduced with addition of AA and HEMA in the Casting Solution. Meanwhile the surface porosity was increased. The surface pore size of the untreated PES membrane was decreased from 138 nm to 45.1 and 40.6 nm with introducing 15 wt.% AA and HEMA, respectively. The experimental results showed that the pure water fluxes of membranes were declined at the presence of AA and HEMA. Moreover, the milk water permeation and protein rejection were improved at these conditions. Finally, the fouling analysis demonstrated that the membranes show fewer tendencies for fouling.
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fabrication of polyethersulfone pes membranes with nano porous surface using potassium perchlorate kclo4 as an additive in the Casting Solution
Desalination, 2010Co-Authors: Ahmad Rahimpour, S S Madaeni, Yaghoub MansourpanahAbstract:Abstract Polyethersulfone (PES) membranes with nano-porous surface were fabricated by addition of potassium perchlorate (KClO 4 ) as an additive in the Casting Solution. The membranes were prepared from PES/polyvinylpyrrolidone (PVP)/KClO 4 /dimethylacetamide (DMAc) via phase inversion induced by immersion precipitation technique. Mixture of water and isopropyl alcohol (IPA) was used as coagulation medium. The viscosity of PES Casting Solution increased with addition of KClO 4 . The contact angle measurements demonstrated that the hydrophilicities of membrane enhanced by increasing the KClO 4 concentration in the Casting Solution. According to SEM analysis, it was found that the addition of KClO 4 had a significant influence on structure of the membrane skin layer and the sub-layer. Membranes with dense surface and sub-layer were formed at this condition. The surface AFM images indicated that the addition of KClO 4 in the Casting Solution resulted in nano-structure membranes with surface small pore size. The effect of KClO 4 on the membrane performance was investigated using cross-flow filtration of pure water and non-skim milk as feeds. The pure water flux through the prepared membranes declined by adding 1, 3 and 5 wt.% of KClO 4 in the Casting Solution. On the other hand, milk water permeation and protein rejection of prepared membranes were improved.
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Improvement of performance and surface properties of nano-porous polyethersulfone (PES) membrane using hydrophilic monomers as additives in the Casting Solution
Journal of Membrane Science, 2010Co-Authors: Ahmad Rahimpour, Sayed Siavash MadaeniAbstract:The effects of hydrophilic monomers e.g. acrylic acid (AA) and 2-hydroxyethylmethacrylate (HEMA) on the morphology and performance of polyethersulfone (PES) membrane were investigated. The membranes were fabricated from a Casting Solution of PES, dimethylacetamide (DMAC), polyvinylpyrrolidone (PVP) and AA or HEMA via phase inversion induced by immersion precipitation. The mixture of water (80. vol.%) and 2-propanole (IPA, 20. vol.%) was employed as gelation media. The prepared membranes were characterized using ATR-FTIR, SEM, AFM, contact angle, viscosity measurements, ultrafiltration performance and fouling analysis. The hydrophilicity of PES membrane was improved after addition of AA and HEMA in the Casting Solution. The morphological studies (SEM and AFM) showed that the average sizes of membrane pores in surface and sub-layer were reduced with addition of AA and HEMA in the Casting Solution. Meanwhile the surface porosity was increased. The surface pore size of the untreated PES membrane was decreased from 138. nm to 45.1 and 40.6. nm with introducing 15. wt.% AA and HEMA, respectively. The experimental results showed that the pure water fluxes of membranes were declined at the presence of AA and HEMA. Moreover, the milk water permeation and protein rejection were improved at these conditions. Finally, the fouling analysis demonstrated that the membranes show fewer tendencies for fouling. © 2010 Elsevier B.V.
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preparation and characterization of hydrophile nano porous polyethersulfone membranes using synthesized poly sulfoxide amide as additive in the Casting Solution
Journal of Membrane Science, 2009Co-Authors: Ahmad Rahimpour, S S Madaeni, Abbas Shockravi, Shahla GhorbaniAbstract:Abstract In this research, poly(sulfoxide-amide) (PSA) containing hydrophile groups was synthesized via phosphorylation polycondensation. The synthesized polymer was added to polyethersulfone (PES) Casting Solution at various concentrations for improving membrane properties. Polyvinylpyrrolidone (PVP, 2 wt%) was added in the Casting Solution as the pore former. The phase inversion induced by immersion precipitation was employed for preparation of asymmetric membranes. The prepared membranes were characterized by contact angle measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical strength evaluation and cross-flow filtration. The contact angle measurements demonstrate that the hydrophilicities of PES membrane are strongly enhanced by increasing the PSA concentration in the Casting Solution. The surface SEM and AFM images show that addition of synthesized PSA in the Casting Solution results in nano-structure membranes with small surface pore size. The pure water fluxes through the prepared membranes were increased by adding 5, 10 and 15 wt% of PSA in the Casting Solution. Moreover, milk water permeation and protein rejection were improved. Furthermore it was found that the addition of PSA in the PES Casting Solution results in membranes with higher mechanical strength.
S S Madaeni - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of PES-based nanofiltration membrane modified by composite PAA-co-PMMA-g-ZnA nanoparticles
Journal of the Iranian Chemical Society, 2016Co-Authors: S. M. Hosseini, Abdolreza Moghadassi, E. Bagheripour, A. R. Hamidi, S S MadaeniAbstract:In the current research, nanocomposite polyethersulfone-based nanofiltration membranes were prepared by composite PAA-co-PMMA-g-ZnA nanoparticles. NF membranes were fabricated by phase inversion through Casting Solution technique. The effect of composite PAA-co-PMMA-g-ZnA nanoparticles concentration into the Casting Solution on physicochemical characteristics of membrane was studied. Scanning optical microscopy images showed uniform particle distribution for the membranes. Scanning electron microscopy images also demonstrated that membrane porosity was enhanced by increase in nanoparticles content ratio. The membrane surface 3D images showed smooth surface for the membranes filled with 0.05, 0.1 and 0.5 wt% nanoparticles. The contact angle results exhibited that membrane hydrophilicity was improved significantly by using of NPs in membrane matrix. The contact angle was decreased from 65.38° for PES membrane to 48.33° for membrane filled with 0.5 wt% nanoparticles. The water permeability was reduced initially by addition of 0.05 wt% nanoparticles into the Casting Solution and then increased by more nanoparticles loading rate (0.1 wt%). The water permeability was decreased again by more increase in nanoparticles loading range from 0.5 to 1 wt%. The salt rejection was improved strongly from 68.4 % for PES to 88.58 % for membrane filled with 0.5 wt% nanoparticles. The membranes mechanical strength was increased sharply from 2835.5 to 3337.3 kPa with addition of nanoparticles into the Casting Solution.
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effect of Casting Solution on morphology and performance of pvdf microfiltration membranes
Chemical Engineering & Technology, 2011Co-Authors: S S Madaeni, A H TaheriAbstract:The effects of preparation-influencing parameters such as polymer concentration, thickness of Casting Solution, and type of solvent on morphology and performance of poly(vinylidene difluoride) (PVDF) microfiltration membranes for the treatment of emulsified oily wastewater were investigated. Flat-sheet membranes were prepared from a Casting Solution of polymer and additive in various solvents by immersing the prepared films in nonsolvent-containing mixtures of water and 2-propanol. The membranes were characterized using scanning electron microscopy. Increasing the polymer concentration and membrane thickness significantly affected the pore size, leading to permeate flux decrease. An attempt was made to correlate the effect of the solvent on membrane morphology and performance employing solubility parameters between solvent and nonsolvent).
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improvement of performance and surface properties of nano porous polyethersulfone pes membrane using hydrophilic monomers as additives in the Casting Solution
Journal of Membrane Science, 2010Co-Authors: Ahmad Rahimpour, S S MadaeniAbstract:Abstract The effects of hydrophilic monomers e.g. acrylic acid (AA) and 2-hydroxyethylmethacrylate (HEMA) on the morphology and performance of polyethersulfone (PES) membrane were investigated. The membranes were fabricated from a Casting Solution of PES, dimethylacetamide (DMAC), polyvinylpyrrolidone (PVP) and AA or HEMA via phase inversion induced by immersion precipitation. The mixture of water (80 vol.%) and 2-propanole (IPA, 20 vol.%) was employed as gelation media. The prepared membranes were characterized using ATR-FTIR, SEM, AFM, contact angle, viscosity measurements, ultrafiltration performance and fouling analysis. The hydrophilicity of PES membrane was improved after addition of AA and HEMA in the Casting Solution. The morphological studies (SEM and AFM) showed that the average sizes of membrane pores in surface and sub-layer were reduced with addition of AA and HEMA in the Casting Solution. Meanwhile the surface porosity was increased. The surface pore size of the untreated PES membrane was decreased from 138 nm to 45.1 and 40.6 nm with introducing 15 wt.% AA and HEMA, respectively. The experimental results showed that the pure water fluxes of membranes were declined at the presence of AA and HEMA. Moreover, the milk water permeation and protein rejection were improved at these conditions. Finally, the fouling analysis demonstrated that the membranes show fewer tendencies for fouling.
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fabrication of polyethersulfone pes membranes with nano porous surface using potassium perchlorate kclo4 as an additive in the Casting Solution
Desalination, 2010Co-Authors: Ahmad Rahimpour, S S Madaeni, Yaghoub MansourpanahAbstract:Abstract Polyethersulfone (PES) membranes with nano-porous surface were fabricated by addition of potassium perchlorate (KClO 4 ) as an additive in the Casting Solution. The membranes were prepared from PES/polyvinylpyrrolidone (PVP)/KClO 4 /dimethylacetamide (DMAc) via phase inversion induced by immersion precipitation technique. Mixture of water and isopropyl alcohol (IPA) was used as coagulation medium. The viscosity of PES Casting Solution increased with addition of KClO 4 . The contact angle measurements demonstrated that the hydrophilicities of membrane enhanced by increasing the KClO 4 concentration in the Casting Solution. According to SEM analysis, it was found that the addition of KClO 4 had a significant influence on structure of the membrane skin layer and the sub-layer. Membranes with dense surface and sub-layer were formed at this condition. The surface AFM images indicated that the addition of KClO 4 in the Casting Solution resulted in nano-structure membranes with surface small pore size. The effect of KClO 4 on the membrane performance was investigated using cross-flow filtration of pure water and non-skim milk as feeds. The pure water flux through the prepared membranes declined by adding 1, 3 and 5 wt.% of KClO 4 in the Casting Solution. On the other hand, milk water permeation and protein rejection of prepared membranes were improved.
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preparation and characterization of hydrophile nano porous polyethersulfone membranes using synthesized poly sulfoxide amide as additive in the Casting Solution
Journal of Membrane Science, 2009Co-Authors: Ahmad Rahimpour, S S Madaeni, Abbas Shockravi, Shahla GhorbaniAbstract:Abstract In this research, poly(sulfoxide-amide) (PSA) containing hydrophile groups was synthesized via phosphorylation polycondensation. The synthesized polymer was added to polyethersulfone (PES) Casting Solution at various concentrations for improving membrane properties. Polyvinylpyrrolidone (PVP, 2 wt%) was added in the Casting Solution as the pore former. The phase inversion induced by immersion precipitation was employed for preparation of asymmetric membranes. The prepared membranes were characterized by contact angle measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical strength evaluation and cross-flow filtration. The contact angle measurements demonstrate that the hydrophilicities of PES membrane are strongly enhanced by increasing the PSA concentration in the Casting Solution. The surface SEM and AFM images show that addition of synthesized PSA in the Casting Solution results in nano-structure membranes with small surface pore size. The pure water fluxes through the prepared membranes were increased by adding 5, 10 and 15 wt% of PSA in the Casting Solution. Moreover, milk water permeation and protein rejection were improved. Furthermore it was found that the addition of PSA in the PES Casting Solution results in membranes with higher mechanical strength.
Ya-nan Yang - One of the best experts on this subject based on the ideXlab platform.
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The research of rheology and thermodynamics of organic-inorganic hybrid membrane during the membrane formation
Journal of Membrane Science, 2008Co-Authors: Ya-nan Yang, Zheng Qing-zhu, Chen Xuesi, Zhang Hui-xuanAbstract:To clarify the mechanism of organic-inorganic hybrid membrane formation by phase-inversion method, the thermodynamical and theological properties of PSF/TiO2 Casting Solution were investigated by the viscosity measurement and the triangle phase diagram, respectively. TiO2 introduction decreased the non-solvent tolerance of Casting Solution with non-solvent 20% ethanol aqueous Solution, which caused thermodynamic enhancement of phase separation, and also resulted in the change of theological properties from Newtonian fluid to non-Newtonian fluid and the viscosity increase of Casting Solution, which induced rheological hindrance in demixing process
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rheological and thermodynamic variation in polysulfone Solution by peg introduction and its effect on kinetics of membrane formation via phase inversion process
Journal of Membrane Science, 2006Co-Authors: Qingzhu Zheng, Ya-nan Yang, Peng WangAbstract:Abstract In order to clarify the mechanism through which poly(ethylene glycol) (PEG) can affect the kinetics of membrane formation, phase-inversion process was used in membrane preparation from polysulfone (PSF) Casting Solution with PEG introduction. The rheological and thermodynamic variation in PSF Solution by PEG introduction was investigated by using the method of viscosity measurement and triangle phase diagram. It was found that PEG addition could work in favor of enhancement thermodynamically and hindrance rheologically in PSF Solution demixing. With the increase of temperature, the viscosity of PSF Casting Solution decreased and the miscibility of PSF Solution with non-solvent increased. On the basis of the relationship between wet membrane thickness and coagulation time, a new method used to calculate kinetics parameter ( D a ) of membrane formation was founded and an equation of D a = d 2 / t was established. With the increase of PEG concentration, it was revealed that D a increased firstly and then decreased with a maximum value of 0.001428 mm 2 /s at certain temperature (20 °C). With the increase of coagulation bath temperature, D a increased continuously when the composition of Casting Solution was constant. D a was mainly influenced by the surface morphology of membrane and the thermodynamic, rheological properties of Casting Solution.
Joaquin Coronas - One of the best experts on this subject based on the ideXlab platform.
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poly ether block amide copolymer membrane for co2 n2 separation the influence of the Casting Solution concentration on its morphology thermal properties and gas separation performance
Royal Society Open Science, 2019Co-Authors: Lidia Martinezizquierdo, Magdalena Malankowska, Javier Sanchezlainez, Carlos Tellez, Joaquin CoronasAbstract:The present work is focused on the study of the effect that the Casting Solution concentration has on the morphology and gas separation performance of poly(ether-block-amide) copolymer membranes (P...
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Poly(ether-block-amide) copolymer membrane for CO2/N2 separation: the influence of the Casting Solution concentration on its morphology, thermal properties and gas separation performance.
Royal Society Open Science, 2019Co-Authors: Lidia Martínez-izquierdo, Magdalena Malankowska, Carlos Tellez, Javier Sánchez-laínez, Joaquin CoronasAbstract:The present work is focused on the study of the effect that the Casting Solution concentration has on the morphology and gas separation performance of poly(ether-block-amide) copolymer membranes (P...
Quanfu An - One of the best experts on this subject based on the ideXlab platform.
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polyelectrolyte complex nanofiltration membranes performance modulation via Casting Solution ph
RSC Advances, 2014Co-Authors: Qiang Zhao, Yanli Ji, Jiakai Wu, Lingling Shao, Quanfu AnAbstract:Nanofiltration (NF) membranes were prepared from a Solution processable polyelectrolyte complex (PEC) between sodium carboxymethyl cellulose (CMCNa) and poly(2-methacryloyloxy ethyl trimethylammonium chloride) (PDMC). Electrostatic complexation structures of the PEC were studied by light transmittance and field emission electron scanning microscopy (FESEM). It is found that the electrostatic complexation structure of the PEC membranes determines their NF performance, which is conveniently tailored via the pH values of Casting Solutions. For membranes prepared at the optimum Solution pH 2.1, their water flux and salt rejection to K2SO4 (1 g L−1) are 18 g m−2 h−1 and 97%, respectively, when the operation pressure and temperature are 0.6 MPa and 25 °C. Both the water permeability and the salt selectivity are substantially improved compared to the pristine CMCNa NF membrane. In addition, antifouling performance of the PEC membrane is improved, coupled with an exceptional stability versus the operation time.
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effect of zero shear viscosity of the Casting Solution on the morphology and permeability of polysulfone membrane prepared via the phase inversion process
Desalination, 2010Co-Authors: Zhenghua Zhang, Quanfu An, Yanli Ji, Jinwen QianAbstract:The zero shear viscosity of two kinds of polysulfone (PSF) Casting Solutions and the morphology and permeability of their membranes prepared via the phase-inversion process were investigated. The zero shear viscosities, dominated by changing the concentration of PSF and the molecular weight of poly(vinyl pyrrolidone) (PVP) additive for the PSF/N, N-Dimethylacetamide (DMAC) binary system and PSF/DMAC/PVP ternary system respectively, were measured by a falling sphere viscometer. The cloud point of Solutions was investigated in the cloud point experiment, and the phase-inversion process was monitored by the light transmittance apparatus. The surface and cross-section morphology of the corresponding membranes were characterized by SEM, and the water flux of the membranes was performed in the permeation experiment. Increasing the viscosity of the Casting Solution leads to the less porous surface and thick-skinned top-layer of the membrane. These experimental results are attributed to the mutable thermodynamic property of the system and the poor diffusion between components during the phase-inversion process, and finally results in the low water flux of PSF membranes. It suggests that the zero shear viscosity of the Casting Solution is one of the most important parameters for the morphology and permeability of membranes prepared via the phase-inversion process with the same coagulation bath.