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Takeshi Matsuura - One of the best experts on this subject based on the ideXlab platform.

  • green silica based ceramic hollow fiber membrane for seawater desalination via direct contact membrane distillation
    Separation and Purification Technology, 2018
    Co-Authors: Siti Khadijah Hubadillah, A F Ismail, Takeshi Matsuura, Juhana Jaafar, Mohd Hafiz Dzarfan Othman, Mukhlis A Rahman, Siti Zulaikha Binti Mohamad Amin
    Abstract:

    Abstract In this work, green silica-based ceramic hollow fiber membranes (CHFMs) derived from rice husk ash waste were successfully prepared via phase inversion and sintering technique. Prior to the fabrication, rice husk waste was converted into amorphous and crystalline silica-based rice husk ash (ARHA and CRHA). The surface of CHFMs could be easily modified to become hydrophobic by grafting with a fluoroalkylsilane (FAS) agent. The CHFMs were characterized before and after grafting using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), measurement of contact angle and Liquid Entry Pressure of water (LEPw), and three-point bending test. The pore size and the porosity of the membrane surface were also evaluated using mercury intrusion porosimetry (MIP). Lotus-leaf structure formed at the surface of HFMs by grafting, leading to a high contact angle of >150°. Direct contact membrane distillation (DCMD) performance of membrane after grafting was conducted for 200 h using the synthetic seawater of various NaCl concentrations at different feed temperatures. The experimental results show that the permeate flux decreased with the increasing feed concentration, whereas it was enhanced with the increasing feed temperature. A high water flux of 38.2 kg/m2 h and salt rejection up to 99.9% were obtained by CHFM prepared from CRHA (CHFM/CRHA).

  • effects of hydrophilic silica nanoparticles and backing material in improving the structure and performance of vmd pvdf membranes
    Separation and Purification Technology, 2016
    Co-Authors: Mohammadali Baghbanzadeh, Dipak Rana, Takeshi Matsuura
    Abstract:

    Abstract Effects of hydrophilic silica nanoparticles and Non-Woven Fabric (NWF) backing material on the properties and performance of the Polyvinylidene Fluoride (PVDF) membrane have been studied in this work. The nanocomposite membranes were prepared by the phase inversion method and characterized in terms of surface pore size, cross-sectional morphology, thickness, porosity, surface roughness and hydrophobicity. The fabricated membranes were subjected to Vacuum Membrane Distillation (VMD) experiments and their performance was evaluated through measuring the pure water flux and salt rejection. According to the results, effects of the hydrophilic nano-additives and NWF polyester enabled much higher VMD flux than the neat PVDF membrane when an appropriate amount of the nano-filler was added, possibly due to increase in the surface pore size and the reduction of the sponge-like layer thickness. The supported nanocomposite membranes possessed appropriate Liquid Entry Pressure (LEP w ) and mechanical strength, which make the membrane applicable in VMD process. When 7.0 wt.% of the silica nanoparticles was incorporated in a NWF supported membrane, the pure water flux became 12749.6 g/m 2  h at feed temperature of 27.5 °C and permeate side Pressure of 1.2 kPa, representing a 2456% increase from the neat PVDF membrane. Almost complete NaCl rejection was also achieved when tested with 35 g/L NaCl aqueous solution.

  • study on structure and vacuum membrane distillation performance of pvdf membranes ii influence of molecular weight
    Chemical Engineering Journal, 2015
    Co-Authors: Zuolong Che, Dipak Rana, Takeshi Matsuura, Derek Meng
    Abstract:

    Abstract Membranes were prepared from three poly(vinylidene fluoride) (PVDF) of different molecular weights by the phase inversion process. The membranes were characterized by scanning electron microscopy, gas permeation tests, contact angle (CA) and Liquid Entry Pressure of water (LEPw) measurements, and further subjected to the test of flux for vacuum membrane distillation (VMD) in a scenario that is applicable for cooling processes. The results showed that the increase in PVDF molecular weight increased the viscosity and thermodynamic instability of the casting solution significantly. Regarding characterization and performance testing, the membrane prepared from the intermediate molecular weight of Kynar® MG 15 polymer showed the highest VMD flux (325 g/m 2  h) at the feed temperature of 27 °C and the lowest LEPw (622 kPa) due to the largest pore size (49.8 nm) observed among all the tested membranes. The highest flux of this particular membrane seems also due to the thinnest finger-like and sponge-like layer.

  • effect of general montmorillonite and cloisite 15a on structural parameters and performance of mixed matrix membranes contactor for co2 absorption
    Chemical Engineering Journal, 2015
    Co-Authors: Mehran Rezaei, Gh. Bakeri, A F Ismail, Takeshi Matsuura, S A Hashemifard
    Abstract:

    Abstract Polyvinylideneflouride (PVDF) hollow fiber mixed matrix membranes (MMMs) were fabricated through wet phase inversion method using general MMT and Cloisite 15A as inorganic fillers. The effect of clay filler loadings (1, 3 and 5 wt% of polymer), their particle size and hydrophobicity on the membrane morphology, structure and performance in gas–Liquid contacting process were investigated. The fabricated MMMs were characterized by scanning electron microscopic (SEM), gas permeation test, hydrophobicity, wetting resistance and CO2 absorption test. As expected, MMMs showed asymmetrical structure, differing in finger-like portion, porosity and pore size. The fabricated MMMs with higher finger-like area and surface porosity showed higher permeance than plain membrane. Furthermore, the wetting resistance in terms of surface hydrophobicity and Liquid Entry Pressure of water increased with loading. From the point of view of physical CO2 absorption, the membranes incorporated with small particle size filler (general MMT-filled PVDF membranes) exhibited higher absorption fluxes than those embedded with large particle size fillers. The highest absorption flux for membrane containing 1 wt% general MMT is 1.0 × 10−3 mol m−2 s−1 at the flow rate of 3.1 m s−1. That flux was approximately 54% and 82% higher than the flux of MMMs with embedded Cloisite 15A of the same loading and plain PVDF membrane, respectively. The obtained flux of synthesized membrane was superior compared to several in-house made and commercial membranes.

  • Effects of superhydrophobic SiO2 nanoparticles on the performance of PVDF flat sheet membranes for vacuum membrane distillation
    Desalination, 2015
    Co-Authors: Johnson E. Efome, Dipak Rana, Takeshi Matsuura, Mohammadali Baghbanzadeh, Christopher Q Lan
    Abstract:

    Abstract Polyvinylidene fluoride (PVDF)/SiO2 flat sheet composite membranes were prepared for vacuum membrane distillation (VMD) by the phase inversion immersion precipitation process. The effect of blending superhydrophobic SiO2 nanoparticles into the PVDF dope solution was studied. The concentration of the nanoparticles in the dope solution was varied at different wt.% (1, 2, 4, 6, 7, 8 and 10 wt.%). The prepared membranes were characterized by scanning electron microscopy, water contact angle, porosity, Liquid Entry Pressure of water, Fourier transformed infrared spectroscopy, and VMD at feed temperature of 27 °C. The nanoparticles enhanced the membrane performance through a reduction in the sponge-like layer thickness and an increase in surface pore size, leading to increased vapour flux with a maximum at 7 wt.%. The salt rejection was greater than 99.98% when a 35 g/L NaCl solution was used as feed. At this concentration, the smallest thickness of the sponge-like layer and largest macro-voids were also achieved. Beyond 7 wt.%, the sponge-like layer became predominant and the flux was reduced. With a vapour flux increase of up to 4 times (from 0.7 to 2.9 kg/m2 h) when compared to the neat membrane, this nanocomposite membrane could be of great potential in the desalination process through VMD.

A F Ismail - One of the best experts on this subject based on the ideXlab platform.

  • green silica based ceramic hollow fiber membrane for seawater desalination via direct contact membrane distillation
    Separation and Purification Technology, 2018
    Co-Authors: Siti Khadijah Hubadillah, A F Ismail, Takeshi Matsuura, Juhana Jaafar, Mohd Hafiz Dzarfan Othman, Mukhlis A Rahman, Siti Zulaikha Binti Mohamad Amin
    Abstract:

    Abstract In this work, green silica-based ceramic hollow fiber membranes (CHFMs) derived from rice husk ash waste were successfully prepared via phase inversion and sintering technique. Prior to the fabrication, rice husk waste was converted into amorphous and crystalline silica-based rice husk ash (ARHA and CRHA). The surface of CHFMs could be easily modified to become hydrophobic by grafting with a fluoroalkylsilane (FAS) agent. The CHFMs were characterized before and after grafting using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), measurement of contact angle and Liquid Entry Pressure of water (LEPw), and three-point bending test. The pore size and the porosity of the membrane surface were also evaluated using mercury intrusion porosimetry (MIP). Lotus-leaf structure formed at the surface of HFMs by grafting, leading to a high contact angle of >150°. Direct contact membrane distillation (DCMD) performance of membrane after grafting was conducted for 200 h using the synthetic seawater of various NaCl concentrations at different feed temperatures. The experimental results show that the permeate flux decreased with the increasing feed concentration, whereas it was enhanced with the increasing feed temperature. A high water flux of 38.2 kg/m2 h and salt rejection up to 99.9% were obtained by CHFM prepared from CRHA (CHFM/CRHA).

  • effect of general montmorillonite and cloisite 15a on structural parameters and performance of mixed matrix membranes contactor for co2 absorption
    Chemical Engineering Journal, 2015
    Co-Authors: Mehran Rezaei, Gh. Bakeri, A F Ismail, Takeshi Matsuura, S A Hashemifard
    Abstract:

    Abstract Polyvinylideneflouride (PVDF) hollow fiber mixed matrix membranes (MMMs) were fabricated through wet phase inversion method using general MMT and Cloisite 15A as inorganic fillers. The effect of clay filler loadings (1, 3 and 5 wt% of polymer), their particle size and hydrophobicity on the membrane morphology, structure and performance in gas–Liquid contacting process were investigated. The fabricated MMMs were characterized by scanning electron microscopic (SEM), gas permeation test, hydrophobicity, wetting resistance and CO2 absorption test. As expected, MMMs showed asymmetrical structure, differing in finger-like portion, porosity and pore size. The fabricated MMMs with higher finger-like area and surface porosity showed higher permeance than plain membrane. Furthermore, the wetting resistance in terms of surface hydrophobicity and Liquid Entry Pressure of water increased with loading. From the point of view of physical CO2 absorption, the membranes incorporated with small particle size filler (general MMT-filled PVDF membranes) exhibited higher absorption fluxes than those embedded with large particle size fillers. The highest absorption flux for membrane containing 1 wt% general MMT is 1.0 × 10−3 mol m−2 s−1 at the flow rate of 3.1 m s−1. That flux was approximately 54% and 82% higher than the flux of MMMs with embedded Cloisite 15A of the same loading and plain PVDF membrane, respectively. The obtained flux of synthesized membrane was superior compared to several in-house made and commercial membranes.

  • polyvinylidene fluoride and polyetherimide hollow fiber membranes for co2 stripping in membrane contactor
    Chemical Engineering Research & Design, 2014
    Co-Authors: R. Naim, A F Ismail, Ng Be Cheer, Mohd Sohaimi Abdullah
    Abstract:

    Porous polyvinylidene fluoride (PVDF) and polyetherimide (PEI) hollow fiber membranes incorporating polyethylene glycol (PEG) were prepared via spinning process for CO2 membrane stripping. CO2 loaded diethanolamine solution was used as Liquid absorbent while N2 was used as a strip gas. The characterization study of the fibers was carried out in terms of permeation test, contact angle measurement and Liquid Entry Pressure (wetting Pressure). Performance study via membrane contactor stripping was carried out at specific operating condition. The experimental results showed that PVDF membrane have high gas permeation, effective surface porosity and contact angle despite having lower Liquid Entry Pressure in comparison with PEI membrane. PVDF-PEG membrane showed the highest stripping flux of 4.0 × 10−2 mol m−2 s−1 at 0.7 ms−1 compared to that of PEI membrane. Although the stripping flux for PEI-PEG membranes was slightly lower than PVDF membrane (e.g. 3.5 × 10−2 mol m−2 s−1 at Liquid velocity of 0.85 ms−1), the membrane wetting Pressure of PEI membrane is higher than hydrophobic PVDF membrane. Long term performance of both membranes showed severe flux reduction but started to level-off after 30 h of operation.

  • effect of polymer concentration on the structure and performance of pei hollow fiber membrane contactor for co2 stripping
    Journal of Hazardous Materials, 2013
    Co-Authors: R. Naim, A F Ismail
    Abstract:

    A series of polyetherimide (PEI) hollow fiber membranes with various polymer concentrations (13–16 wt.%) for CO2 stripping process in membrane contactor application was fabricated via wet phase inversion method. The PEI membranes were characterized in terms of Liquid Entry Pressure, contact angle, gas permeation and morphology analysis. CO2 stripping performance was investigated via membrane contactor system in a stainless steel module with aqueous diethanolamine as Liquid absorbent. The hollow fiber membranes showed decreasing patterns in gas permeation, contact angle, mean pore size and effective surface porosity with increasing polymer concentration. On the contrary, wetting Pressure of PEI membranes has enhanced significantly with polymer concentration. Various polymer concentrations have different effects on the CO2 stripping flux in which membrane with 14 wt.% polymer concentration showed the highest stripping flux of 2.7 × 10−2 mol/m2 s. From the performance comparison with other commercial membrane, it is anticipated that the PEI membrane has a good prospect in CO2 stripping via membrane contactor.

  • effect of polymer concentration on the structure and performance of pei hollow fiber membrane contactor for co2 stripping
    Journal of Hazardous Materials, 2013
    Co-Authors: R. Naim, A F Ismail
    Abstract:

    A series of polyetherimide (PEI) hollow fiber membranes with various polymer concentrations (13–16 wt.%) for CO2 stripping process in membrane contactor application was fabricated via wet phase inversion method. The PEI membranes were characterized in terms of Liquid Entry Pressure, contact angle, gas permeation and morphology analysis. CO2 stripping performance was investigated via membrane contactor system in a stainless steel module with aqueous diethanolamine as Liquid absorbent. The hollow fiber membranes showed decreasing patterns in gas permeation, contact angle, mean pore size and effective surface porosity with increasing polymer concentration. On the contrary, wetting Pressure of PEI membranes has enhanced significantly with polymer concentration. Various polymer concentrations have different effects on the CO2 stripping flux in which membrane with 14 wt.% polymer concentration showed the highest stripping flux of 2.7 × 10−2 mol/m2 s. From the performance comparison with other commercial membrane, it is anticipated that the PEI membrane has a good prospect in CO2 stripping via membrane contactor.

R. Naim - One of the best experts on this subject based on the ideXlab platform.

  • Characterization Study of PVDF/ Cloisite Hollow Fiber Membrane in Aqueous Diethanolamine
    Journal of Applied Membrane Science & Technology, 2017
    Co-Authors: R. Naim, S. Abdullah, N. Zulkifli
    Abstract:

    Different concentrations of PVDF/Cloisite hollow fiber membranes were prepared and studied via immersion test. The differences in membrane properties were observed by immersion tests at 10 days, 20 days and 30 days in DEA solution. The membranes were characterized via Liquid Entry Pressure (LEPW) and contact angle. Surface morphology analysis study was conducted before and after immersion test using scanning electron microscopy. From the result obtained, the Liquid Entry Pressure and contact angle showed decreasing effect after immersion in DEA solution for 30 days. SEM analysis indicated that increasing DEA concentration creates more finger-like structure compared to pristine membrane. Incorporation of cloisite into PVDF membranes improves the contact angle value but development of more finger-like structure is subjected to wetting problem.

  • PVDF-CLOISITE hollow fiber membrane for CO2 absorption via membrane contactor
    Penerbit Universiti Teknologi Malaysia, 2017
    Co-Authors: Izzati, Ahmad Rudaini, R. Naim, Sureena Abdullah, M. N. Mohktar, Juhana Jaafar
    Abstract:

    The effect of cloisite concentrations on CO2 absorption via polyvinylidene fluoride-cloisite hollow fiber in membrane contactor system was investigated. PVDF polymer was modified by introducing different compositions of cloisite clay (S1: 0%, S2:1 wt%, S3: 3 wt% and S4: 5 wt%) into the polymer solution. The hollow fiber membranes were examined via Liquid Entry Pressure (LEPw), contact angle and scanning electron microscope (SEM). CO2 absorption test was conducted at different Liquid absorbent flow rates of 1M MEA. S4 gives highest Liquid Entry Pressure value and S3 obtained highest contact angle value at around 87.21º. Different concentrations of cloisite exhibited various finger-like structure with sponge-like morphology on the membrane lumen side. Meanwhile, the highest CO2 absorption flux of 3.41×10-2 mol/m2.s at flowrate of 200 ml/min was obtained for membrane S4. Long term performance for membrane S4 up to 55 hours of CO2 absorption showed increasing absorption trend up to 6.78 ×10-2 mol/m2.s of CO2 fluxes

  • polyvinylidene fluoride and polyetherimide hollow fiber membranes for co2 stripping in membrane contactor
    Chemical Engineering Research & Design, 2014
    Co-Authors: R. Naim, A F Ismail, Ng Be Cheer, Mohd Sohaimi Abdullah
    Abstract:

    Porous polyvinylidene fluoride (PVDF) and polyetherimide (PEI) hollow fiber membranes incorporating polyethylene glycol (PEG) were prepared via spinning process for CO2 membrane stripping. CO2 loaded diethanolamine solution was used as Liquid absorbent while N2 was used as a strip gas. The characterization study of the fibers was carried out in terms of permeation test, contact angle measurement and Liquid Entry Pressure (wetting Pressure). Performance study via membrane contactor stripping was carried out at specific operating condition. The experimental results showed that PVDF membrane have high gas permeation, effective surface porosity and contact angle despite having lower Liquid Entry Pressure in comparison with PEI membrane. PVDF-PEG membrane showed the highest stripping flux of 4.0 × 10−2 mol m−2 s−1 at 0.7 ms−1 compared to that of PEI membrane. Although the stripping flux for PEI-PEG membranes was slightly lower than PVDF membrane (e.g. 3.5 × 10−2 mol m−2 s−1 at Liquid velocity of 0.85 ms−1), the membrane wetting Pressure of PEI membrane is higher than hydrophobic PVDF membrane. Long term performance of both membranes showed severe flux reduction but started to level-off after 30 h of operation.

  • Polyvinylidene fluoride and polyetherimide hollow fiber membranes for carbon dioxide stripping in gas-Liquid membrane contactor
    2014
    Co-Authors: R. Naim
    Abstract:

    Porous polyvinylidene fluoride (PVDF) and polyetherimide (PET) hollow fiber membranes were developed for CO 2 stripping in membrane contactor system. The effects of various types of additives (lithium chloride, polyethylene glycol, phosphoric acid, methanol and glycerol) and different concentrations of lithium chloride (LiC1) on the membrane structure and CO 2 stripping performance of PVDF membrane were investigated. Different polymer concentrations of PEI membranes were studied and their effects on membrane structure and CO 2 stripping performance were evaluated. Long term performance of PVDF and PEI membranes were compared and analyzed. The membranes were characterized in terms of gas permeation, contact angle, membrane porosity, Liquid Entry Pressure and tensile strength. Atomic force microscopy (AFM) was used to examine the membrane surface roughness while the membrane morphology was investigated using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM). Mass transfer resistance of the system was further calculated based on the experimental data. The addition of additives improved the PVDF membrane characteristics in terms of Liquid Entry Pressure and stripping flux. This could be caused by the thermodynamic (polymer-solvent interaction) and kinetic effects (solution viscosity) on the phase inversion process. These effects also contributed to the reduction of membrane pore size, contact angle and gas permeability of PVDF membranes. The CO 2 stripping performance of PVDF with polyethylene glycol (PEG) additive showed the highest stripping flux and efficiency compared to the other membrane samples. The increase in the concentration of LiC1 in PVDF membrane produced high stripping fluxes which can be associated to low surface roughness and mass transfer resistance. For PET membrane, increasing the polymer concentration had significantly enhanced the wetting Pressure whilst reducing the gas permeation. From FESEM analysis, PEI hollow fiber membranes showed finger-like structure similar to PVDF membrane but there was variation in thickness of spongelike layer in the middle of the membrane cross-structure. Comparative study between PVDF and PEI hollow fiber membranes possessed different microstructures with PVDF-PEG membrane achieving the highest stripping flux of 4.Ox 10-2 mol/m2s. Although PEI membranes had higher resistance compared to PVDF membranes in terms of Liquid Entry Pressure, both membranes suffered reduction of stripping flux after operating more than 20 hours. However, the percentage of flux reduction during long hour operation for PVDF membrane was 34% higher than PEI membrane. In addition, PVDF membranes demonstrated higher stripping flux compared to PEI membranes. Therefore, highly hydrophobic membranes with reasonable pore sizes and microstructure are preferred in membrane contactor system for CO 2 stripping application

  • effect of polymer concentration on the structure and performance of pei hollow fiber membrane contactor for co2 stripping
    Journal of Hazardous Materials, 2013
    Co-Authors: R. Naim, A F Ismail
    Abstract:

    A series of polyetherimide (PEI) hollow fiber membranes with various polymer concentrations (13–16 wt.%) for CO2 stripping process in membrane contactor application was fabricated via wet phase inversion method. The PEI membranes were characterized in terms of Liquid Entry Pressure, contact angle, gas permeation and morphology analysis. CO2 stripping performance was investigated via membrane contactor system in a stainless steel module with aqueous diethanolamine as Liquid absorbent. The hollow fiber membranes showed decreasing patterns in gas permeation, contact angle, mean pore size and effective surface porosity with increasing polymer concentration. On the contrary, wetting Pressure of PEI membranes has enhanced significantly with polymer concentration. Various polymer concentrations have different effects on the CO2 stripping flux in which membrane with 14 wt.% polymer concentration showed the highest stripping flux of 2.7 × 10−2 mol/m2 s. From the performance comparison with other commercial membrane, it is anticipated that the PEI membrane has a good prospect in CO2 stripping via membrane contactor.

Gh. Bakeri - One of the best experts on this subject based on the ideXlab platform.

  • effect of general montmorillonite and cloisite 15a on structural parameters and performance of mixed matrix membranes contactor for co2 absorption
    Chemical Engineering Journal, 2015
    Co-Authors: Mehran Rezaei, Gh. Bakeri, A F Ismail, Takeshi Matsuura, S A Hashemifard
    Abstract:

    Abstract Polyvinylideneflouride (PVDF) hollow fiber mixed matrix membranes (MMMs) were fabricated through wet phase inversion method using general MMT and Cloisite 15A as inorganic fillers. The effect of clay filler loadings (1, 3 and 5 wt% of polymer), their particle size and hydrophobicity on the membrane morphology, structure and performance in gas–Liquid contacting process were investigated. The fabricated MMMs were characterized by scanning electron microscopic (SEM), gas permeation test, hydrophobicity, wetting resistance and CO2 absorption test. As expected, MMMs showed asymmetrical structure, differing in finger-like portion, porosity and pore size. The fabricated MMMs with higher finger-like area and surface porosity showed higher permeance than plain membrane. Furthermore, the wetting resistance in terms of surface hydrophobicity and Liquid Entry Pressure of water increased with loading. From the point of view of physical CO2 absorption, the membranes incorporated with small particle size filler (general MMT-filled PVDF membranes) exhibited higher absorption fluxes than those embedded with large particle size fillers. The highest absorption flux for membrane containing 1 wt% general MMT is 1.0 × 10−3 mol m−2 s−1 at the flow rate of 3.1 m s−1. That flux was approximately 54% and 82% higher than the flux of MMMs with embedded Cloisite 15A of the same loading and plain PVDF membrane, respectively. The obtained flux of synthesized membrane was superior compared to several in-house made and commercial membranes.

  • development of high performance surface modified polyetherimide hollow fiber membrane for gas Liquid contacting processes
    Chemical Engineering Journal, 2012
    Co-Authors: Gh. Bakeri, A F Ismail, Dipak Rana
    Abstract:

    Abstract Low wettability is a vital characteristic for the membrane used in membrane contactor. Blending surface modifying macromolecule (SMM) in spinning dope is an interesting method to enhance the hydrophobicity of membrane and in this research, the effect of SMM on the properties and structure of polyetherimide (PEI) hollow fiber membrane in terms of mean pore size, Liquid Entry Pressure of water (LEPw), membrane porosity and contact angle was investigated and compared with the properties of the PEI membrane without SMM. Furthermore the performance of PEI surface modified membrane in contactor applications in terms of CO2 absorption with distilled water was evaluated and compared with the absorption flux of PEI membrane without SMM and also, with the absorption flux of commercial and in-house made hydrophobic membranes which shows superior performance of surface modified PEI membrane e.g. in case of water in lumen side and pure CO2 in shell side of contactor and at VLiquid = 0.5 m s−1, the absorption flux of PEI surface modified membrane is 2.94 × 10−3 mol m−2 s−1 which is 114% higher than PEI without SMM and 73% higher than commercial membrane contactor, Celgard MiniModule® 0.75X5.

  • a novel surface modified polyetherimide hollow fiber membrane for gas Liquid contacting processes
    Separation and Purification Technology, 2012
    Co-Authors: Gh. Bakeri, A F Ismail, Dipak Rana
    Abstract:

    Abstract A novel surface modified polyetherimide (PEI) hollow fiber membrane was fabricated via dry–wet phased inversion process where the spinning dope contains Surface Modifying Macromolecule (SMM). The surface modified membrane exhibited large pore size, higher effective surface porosity, contact angle and porosity but lower Liquid Entry Pressure of water compared to polyetherimide hollow fiber membrane without SMM. The performance of surface modified membrane in contactor application for gas separation process was evaluated based on CO 2 absorption process using water as absorbent and pure CO 2 and 20:80 CO 2 /CH 4 gas mixture. The results show that surface modified membranes have superior performance compared to commercial and in-house made hydrophobic membranes such as polypropylene and polytetrafluoroethylene, e.g., in the case of pure CO 2 in the shell side and distilled water in the lumen side, the surface modified PEI membrane shows 72% higher absorption flux than commercial membrane contactor, Celgard MiniModule® 0.75X5 which is made of polypropylene membranes, when the Liquid velocity is 0.4 m s −1 .

  • effect of polymer concentration on the structure and performance of polyetherimide hollow fiber membranes
    Journal of Membrane Science, 2010
    Co-Authors: Mojtaba Shariatyniassar, Gh. Bakeri, A F Ismail, T Matsuura
    Abstract:

    Abstract In this paper, polyetherimide (PEI) hollow fiber membranes were used in gas–Liquid contacting process. Porous polyetherimide hollow fiber membranes were fabricated via wet phase inversion method. The polymer concentration in dope solution varied from 10 to 15 wt%. Water was used as internal and external coagulant. Gas permeation test using helium as test gas, Liquid Entry Pressure of water (LEPw) test and scanning electron microscopy (SEM) were used for membrane characterization. The mean pore size, effective surface porosity and void fraction of membranes decreased as the polymer concentration increased, while LEPw and membrane density increased. CO2 absorption rate of fabricated membranes were measured in a gas–Liquid hollow fiber membrane contactor system using distilled water as absorbent and the results showed that CO2 absorption rate of membranes increases as polymer concentration decreases. In addition, CO2 absorption rate of hollow fiber membranes in which polyetherimide concentration was between 10 and 12 wt%, was higher than commercial PVDF hollow fiber membranes.

Dipak Rana - One of the best experts on this subject based on the ideXlab platform.

  • enhanced performance of pvdf nanocomposite membrane by nanofiber coating a membrane for sustainable desalination through md
    Water Research, 2016
    Co-Authors: Johnson E. Efome, Dipak Rana
    Abstract:

    Abstract Membrane distillation (MD) is a promising separation technique capable of being used in the desalination of marine and brackish water. Poly(vinylidene fluoride) (PVDF) flat sheet nano-composite membranes were surface modified by coating with electro-spun PVDF nano-fibres to increase the surface hydrophobicity. For this purpose, the nano-composite membrane containing 7 wt.% superhydrophobic SiO 2 nano-particles, which showed the highest flux in our previous work, was first subjected to pore size augmentation by increasing the concentration of the pore forming agent (Di-ionized water). Then, the prepared flat sheet membranes were subjected to nanofibres coating by electro-spinning. The uncoated and coated composite fabricated membranes were characterized using contact angle, Liquid Entry Pressure of water, and scanning electron microscopy. The membranes were further tested for 6 h desalination by direct contact membrane distillation (DCMD) and vacuum membrane distillation (VMD), with a 3.5 wt.% synthetic NaCl aq as the feed. In DCMD the feed Liquid and permeate side temperature were maintained at 27.5 °C and 15 °C, respectively. For VMD, the feed Liquid temperature was 27 °C and a vacuum of 94.8 kPa was applied on the permeate side. The maximum permeate flux achieved was 3.2 kg/m 2 .h for VMD and 6.5 kg/m 2 .h for DCMD. The salt rejection obtained was higher than 99.98%. The coated membranes showed a more stable flux than the uncoated membranes indicating that the double layered membranes have great potential in solving the pore wetting problem in MD.

  • effects of hydrophilic silica nanoparticles and backing material in improving the structure and performance of vmd pvdf membranes
    Separation and Purification Technology, 2016
    Co-Authors: Mohammadali Baghbanzadeh, Dipak Rana, Takeshi Matsuura
    Abstract:

    Abstract Effects of hydrophilic silica nanoparticles and Non-Woven Fabric (NWF) backing material on the properties and performance of the Polyvinylidene Fluoride (PVDF) membrane have been studied in this work. The nanocomposite membranes were prepared by the phase inversion method and characterized in terms of surface pore size, cross-sectional morphology, thickness, porosity, surface roughness and hydrophobicity. The fabricated membranes were subjected to Vacuum Membrane Distillation (VMD) experiments and their performance was evaluated through measuring the pure water flux and salt rejection. According to the results, effects of the hydrophilic nano-additives and NWF polyester enabled much higher VMD flux than the neat PVDF membrane when an appropriate amount of the nano-filler was added, possibly due to increase in the surface pore size and the reduction of the sponge-like layer thickness. The supported nanocomposite membranes possessed appropriate Liquid Entry Pressure (LEP w ) and mechanical strength, which make the membrane applicable in VMD process. When 7.0 wt.% of the silica nanoparticles was incorporated in a NWF supported membrane, the pure water flux became 12749.6 g/m 2  h at feed temperature of 27.5 °C and permeate side Pressure of 1.2 kPa, representing a 2456% increase from the neat PVDF membrane. Almost complete NaCl rejection was also achieved when tested with 35 g/L NaCl aqueous solution.

  • study on structure and vacuum membrane distillation performance of pvdf membranes ii influence of molecular weight
    Chemical Engineering Journal, 2015
    Co-Authors: Zuolong Che, Dipak Rana, Takeshi Matsuura, Derek Meng
    Abstract:

    Abstract Membranes were prepared from three poly(vinylidene fluoride) (PVDF) of different molecular weights by the phase inversion process. The membranes were characterized by scanning electron microscopy, gas permeation tests, contact angle (CA) and Liquid Entry Pressure of water (LEPw) measurements, and further subjected to the test of flux for vacuum membrane distillation (VMD) in a scenario that is applicable for cooling processes. The results showed that the increase in PVDF molecular weight increased the viscosity and thermodynamic instability of the casting solution significantly. Regarding characterization and performance testing, the membrane prepared from the intermediate molecular weight of Kynar® MG 15 polymer showed the highest VMD flux (325 g/m 2  h) at the feed temperature of 27 °C and the lowest LEPw (622 kPa) due to the largest pore size (49.8 nm) observed among all the tested membranes. The highest flux of this particular membrane seems also due to the thinnest finger-like and sponge-like layer.

  • Effects of superhydrophobic SiO2 nanoparticles on the performance of PVDF flat sheet membranes for vacuum membrane distillation
    Desalination, 2015
    Co-Authors: Johnson E. Efome, Dipak Rana, Takeshi Matsuura, Mohammadali Baghbanzadeh, Christopher Q Lan
    Abstract:

    Abstract Polyvinylidene fluoride (PVDF)/SiO2 flat sheet composite membranes were prepared for vacuum membrane distillation (VMD) by the phase inversion immersion precipitation process. The effect of blending superhydrophobic SiO2 nanoparticles into the PVDF dope solution was studied. The concentration of the nanoparticles in the dope solution was varied at different wt.% (1, 2, 4, 6, 7, 8 and 10 wt.%). The prepared membranes were characterized by scanning electron microscopy, water contact angle, porosity, Liquid Entry Pressure of water, Fourier transformed infrared spectroscopy, and VMD at feed temperature of 27 °C. The nanoparticles enhanced the membrane performance through a reduction in the sponge-like layer thickness and an increase in surface pore size, leading to increased vapour flux with a maximum at 7 wt.%. The salt rejection was greater than 99.98% when a 35 g/L NaCl solution was used as feed. At this concentration, the smallest thickness of the sponge-like layer and largest macro-voids were also achieved. Beyond 7 wt.%, the sponge-like layer became predominant and the flux was reduced. With a vapour flux increase of up to 4 times (from 0.7 to 2.9 kg/m2 h) when compared to the neat membrane, this nanocomposite membrane could be of great potential in the desalination process through VMD.

  • effect of hydrophobic surface modifying macromolecules on differently produced pvdf membranes for direct contact membrane distillation
    Chemical Engineering Journal, 2014
    Co-Authors: J A Prince, Gurdev Singh, T Matsuura, Dipak Rana, T S Shanmugasundaram
    Abstract:

    Abstract Hydrophobic surface modifying macromolecules (SMM) and pore forming poly(vinyl pyrrolidone) (PVP) were added to fabricate poly(vinylidene fluoride) (PVDF)-PVP-hydrophobic SMM composite membranes through the phase inversion process. The composite PVDF-SMM nano-fibers membranes were also fabricated. The SMM was characterized in details by nuclear magnetic resonance spectroscopy. The membranes were characterized using the contact angle, Liquid Entry Pressure of water, scanning electron microscopy, and porometry measurements. Both cast and nanofiber membranes were tested by direct contact membrane distillation (DCMD) with feed 3.5 wt% NaCl solution. Finally, the membrane performance of cast and nanofiber membranes was compared. The prepared hydrophobic SMM modified PVDF electro-spun nano-fibers membranes when combined with the casted membranes are very promising in DCMD for sea water desalination after running for 48 h operational timeframe.