Effect of Pore-Forming Agents on Structure and Properties of PVDF/PVC Blend Membranes

2009 ◽  
Vol 79-82 ◽  
pp. 1627-1630 ◽  
Author(s):  
Hui Ling Shen ◽  
Lu Bai ◽  
Hua Liao ◽  
Chang Fa Xiao ◽  
Shi Ru Jia
Keyword(s):  
Pore Size ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Capillary Flow ◽  
Removal Rate ◽  
Pure Water ◽  
Membrane Formation ◽  
Membrane Pore ◽  
Blend Membrane ◽  
Blend Membranes

By phase inversion process, the polyvinylidene fluoride (PVDF) with polyvinyl chloride (PVC) blend membrane was prepared. In which, as pore-forming agents, the polyethylene glycol (PEG), poly(vinylpyrrolidone) (PVP) and lithium chloride (LiCl) was separately added into PVDF/PVC casting solution. The effect of each pore-forming agent on the kinetics of membrane formation and properties of PVDF/PVC blend membrane were investigated respectively. Using the capillary flow porometry, the microstructure and morphology of PVDF/PVC blend membrane were quantitatively characterized. The results show that by respectively adding PEG, PVP or LiCl, it emphasizes the rate of solvent diffusion from PVDF/PVC solution during the phase inversion or membrane formation, and the porosity of membrane gets increasing. The pure water flux of PVDF/PVC blend membrane achieves enhancement obviously. At the same time, the rejection is decreased in a certain degree. Comparison with PEG or LiCl, PVP has more effect on the membrane pore-forming action. The microstructure analysis indicates that based on the same formulation, by selecting PEG or LiCl as pore-forming agent, formatted PVDF/PVC blend membranes achieve equivalent mean pore size. However, there is a little larger mean pore size distributed in the membrane by using PVP instead of PEG or LiCl. The application of purifying ε-polylysine (ε-PL) by using the PVDF/PVC blend membrane with PVP, the results reveal that the protein removal rate can be around 62.33% and the filterable and permeated ε-PL kept at 70.79% yield.

scholarly journals Statistical Analysis of Synthesis Parameters to Fabricate PVDF/PVP/TiO2 Membranes via Phase-Inversion with Enhanced Filtration Performance and Photocatalytic Properties

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 113
Author(s):  
Erika Nascimben Santos ◽  
Ákos Fazekas ◽  
Cecilia Hodúr ◽  
Zsuzsanna László ◽  
Sándor Beszédes ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Statistical Analysis ◽  
Pore Size ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Pure Water ◽  
Water Flux ◽  
Pore Sizes ◽  
Small Pore ◽  
Pure Water Flux

Non-solvent induced phase-inversion is one of the most used methods to fabricate membranes. However, there are only a few studies supported by statistical analysis on how the different fabrication conditions affect the formation and performance of membranes. In this paper, a central composite design was employed to analyze how different fabrication conditions affect the pure water flux, pore size, and photocatalytic activity of polyvinylidene fluoride (PVDF) membranes. Polyvinylpyrrolidone (PVP) was used to form pores, and titanium dioxide (TiO2) to ensure the photocatalytic activity of the membranes. The studied bath temperatures (15 to 25 °C) and evaporation times (0 to 60 s) did not significantly affect the pore size and pure water flux of the membranes. The concentration of PVDF (12.5 to 17.5%) affected the viscosity, formation capability, and pore sizes. PVDF at high concentrations resulted in membranes with small pore sizes. PVP affected the pore size and should be used to a limited extent to avoid possible hole formation. TiO2 contents were responsible for the decolorization of a methyl orange solution (10−5 M) up to 90% over the period studied (30 h). A higher content of TiO2 did not increase the decolorization rate. Acidic conditions increased the photocatalytic activity of the TiO2-membranes.

Influence of Hydrophilic Polymer on Proteins Separation, Molecular Weight Cut-off (MWCO) and Average Pore Size of Polysulfone Blend Membrane

2015 ◽  
Vol 74 (7) ◽  
Author(s):  
Asmadi Ali ◽  
Rosli Mohd Yunus ◽  
Mohamad Awang ◽  
Mohd Azizi Che Yunus
Keyword(s):  
Molecular Weight ◽  
Pore Size ◽  
Structural Properties ◽  
Phase Inversion ◽  
Average Pore Size ◽  
Separation Performance ◽  
Average Pore ◽  
Blend Membrane ◽  
Blend Membranes ◽  
Wet Phase Inversion

The aim of this study is to investigate the influence of different composition of cellulose acetate phtalate (CAP) on the membrane structural properties of polysulfone (PSf) membrane which in turn affect the separation performance of PSf/CAP blend membrane. The PSf/CAP blend membranes were prepared by using casting solutions contain 17 wt% of polymer via wet phase inversion process. The results showed that increasing the composition of CAP in PSf/CAP blend membranes increased molecular weight cut-off (MWCO), average pore size and pore density which then increased protein solution permeate fluxes but reduced proteins rejection of PSf/CAP blend membranes. Pure PSf membranehas the lowest membrane structural properties compared to blend membranes. This characteristic contributed to decrease in protein permeation flux and increase proteins rejection. 

scholarly journals Synthesis, characterization and filtration performance of the polyvinylidene fluoride membrane modified by poly(methyl ethacrylate-co-2-acrylamido-2-methylpropane sulfonic acid)

2018 ◽  
Vol 19 (4) ◽  
pp. 1279-1285
Author(s):  
Q. Y. Zhang ◽  
Q. An ◽  
Y. G. Guo ◽  
J. Zhang ◽  
K. Y. Zhao
Keyword(s):  
Sulfonic Acid ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Pure Water ◽  
Water Flux ◽  
Contact Angles ◽  
Fouling Resistance ◽  
Inversion Process ◽  
Pvdf Membrane ◽  
Pure Water Flux

Abstract To enhance the anti-fouling and separating properties of polyvinylidene fluoride (PVDF) membranes, an amphiphilic copolymer of methyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid, poly(MMA-co-AMPS), was designed and synthesized. Through a phase-inversion process, the poly(MMA-co-AMPS) were fully dispersed in the PVDF membrane. The properties of membrane including the surface and cross-section morphology, surface wettability and fouling resistance under different pH solutions were investigated. Compared to the unmodified PVDF membranes, the contact angles of modified PVDF membranes decreased from 80.6° to 71.6°, and the pure water flux increased from 54 to 71 L·m−2·h−1. In addition, the hybrid PVDF membrane containing 0.5 wt% copolymers demonstrated an larger permeability, better fouling resistance and higher recovery ratio via pure water backlashing, when it was compared with the other blend membranes, and the virgin one in the cyclic test of anti-fouling. The modified membranes with the copolymers possessed an outstanding performance and may be used for further water treatment applications.

scholarly journals Membrane distillation crystallization using PVDF membrane incorporated with TiO2 nanoparticles and nanocellulose

2020 ◽  
Vol 20 (5) ◽  
pp. 1629-1642 ◽  
Author(s):  
Hoi-Fang Tan ◽  
Why-Ling Tan ◽  
N. Hamzah ◽  
M. H. K. Ng ◽  
B. S. Ooi ◽  
...  
Keyword(s):  
Pore Size ◽  
Tio2 Nanoparticles ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Membrane Distillation ◽  
Coagulation Bath ◽  
Membrane Thickness ◽  
Permeate Flux ◽  
Sem Images ◽  
Pvdf Membrane

Abstract Polyvinylidene fluoride (PVDF) membrane was improved using TiO2 nanoparticles and nanocellulose for membrane distillation crystallization in this work. Besides the addition of TiO2 nanoparticles and nanocellulose, PVDF membrane was post-modified with octadecyltrichlorosilane after phase inversion using a dual coagulation bath. The addition of hydrophilic TiO2 nanoparticles and nanocellulose reduced membrane hydrophobicity, but the dispersed TiO2 nanoparticles assisted silane modification to improve surface hydrophobicity. Besides reducing the agglomeration of TiO2 nanoparticles, nanocellulose induced the formation of larger pore size and higher porosity as proven in SEM images and gravimetric measurement, respectively. The abundant moieties of nanocellulose accelerated the exchange between solvent and non-solvent during phase inversion for the formation of large pore size and porosity, but membrane thickness increased due to the thickening effects. The modified membrane showed higher water permeate flux in membrane distillation with salt rejection greater than 97%. Severe fouling in membrane distillation crystallization was not observed.

scholarly journals Impact of membrane pore structure on protein detection sensitivity of affinity-based immunoassay

2016 ◽  
Vol 18 (2) ◽  
pp. 97-103 ◽  
Author(s):  
A.L. Ahmad ◽  
N. Ideris ◽  
B.S. Ooi ◽  
S.C. Low ◽  
A. Ismail
Keyword(s):  
Pore Size ◽  
Surface Area ◽  
Protein Spot ◽  
Polyvinylidene Fluoride ◽  
Membrane Surface ◽  
Protein Detection ◽  
Protein Immobilization ◽  
Total Surface Area ◽  
Detection Sensitivity ◽  
Membrane Pore

Abstract Understanding a membrane’s morphology is important for controlling its final performance during protein immobilization. Porous, symmetric membranes were prepared from a polyvinylidene fluoride/N-methyl-2-pyrrolidinone solution by phase inversion process, to obtain membrane with various microsized pores. The concentration and surface area of aprotein dotted on the membrane surface were measured by staining with Ponceau S dye. The dotted protein was further scanned and analysed to perform quantitative measurements for relative comparison. The intensity of the red protein spot and its surface area varied depending on the membrane pore size, demonstrating the dependence of protein immobilization on this factor. The membrane with the smallest pore size (M3) showed the highest protein spot intensity and surface area when examined at different protein concentrations. An increase in the applied protein volume showed a linearity proportional trend to the total surface area, and an uneven round dot shape was observed at a large applied volume of protein solution.

Effects of polymer blend composition on membrane properties and separation performance of PEES/PEI blend membrane

2016 ◽  
Vol 29 (4) ◽  
pp. 467-475 ◽  
Author(s):  
R Saranya ◽  
JS Beril ◽  
D Mohan
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Protein Separation ◽  
Pure Water ◽  
Water Flux ◽  
Membrane Properties ◽  
Separation Performance ◽  
Blend Membrane ◽  
Blend Membranes ◽  
Protein Rejection

In this work, an attempt has been made for protein rejection from aqueous solution using ultrafiltration blend membrane based on poly(phenylene ether ether sulfone) (PEES) and polyetherimide (PEI) was prepared in various blend compositions. Prepared membranes were characterized in terms of pure water flux, water content, membrane hydraulic resistance, porosity, contact angle, scanning electron microscopy, thermogravimetric analysis, and attenuated total reflectance-Fourier transform infrared spectroscopy. Studies were carried out to find out the rejection of proteins such as trypsin, pepsin, egg albumin, and bovine serum albumin. The extent of protein separation is directly proportional to molecular weight of protein. Pristine PEES membrane exhibited high-percentage protein rejection of BSA (92.7%), EA (88.2%), pepsin (85.8%), and trypsin (82.2%) compared to PEES/PEI blend membranes. PEES/PEI blend membranes have better hydrophilic property compared to pristine PEES membrane. Pristine PEES has a contact angle of 97.8°, embedded with PEI and reduced to 67.9°. The thermal stability of the membrane was slightly decreased when the percentage of PEI composition into the PEES/PEI blend increased and observed that the pure PEES membrane has superior thermal stability than PEES/PEI blend membranes

High performance polyvinylidene fluoride (PVDF) mixed matrix membrane (MMM) doped by various zeolite imidazolate frameworks

2020 ◽  
pp. 095400832095252
Author(s):  
Lian-Jing Liu ◽  
Gui-E Chen ◽  
Hai-Fang Mao ◽  
Yang Wang ◽  
Jia-Jun Wan
Keyword(s):  
Pore Size ◽  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Pure Water ◽  
Water Flux ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Brilliant Blue ◽  
Mixed Matrix Membrane ◽  
Zeolitic Imidazolate Framework

Zeolitic imidazolate framework (ZIF-8) in three particle sizes (40, 70 and 100 nm) was prepared through both solvothermal and hydrothermal methods and employed to decorate polyvinylidene fluoride (PVDF). The finger-like macro-voids, sponge-like poly-porous morphology and surface roughness of prepared membranes were characterized by SEM and AFM microscopy. The FTIR spectrum and XPS analysis bear out the chemical component. ZIF-8 has the characteristics of higher porosity and appropriate pore size, which is a condition for improving the permeability and pollution resistance of the modified membrane. Results indicated that different ZIF-8s have different enhancement effects on PVDF MMM. 100 nm ZIF-8 membrane possessed pure water flux (PWF) of 350 L m−2h−1, which was 10 times more than the bare membrane (30 L m−2h−1), and OVA flux recovery ration (FRR%) is 98%. 40 nm ZIF-8 membrane owned BSA FRR% of 98.4%. The 70 nm ZIF-8 showed the best mechanical properties. The dynamic contact angles of UP-Z70 ranged from 104.5° to 62.5° within 180 s. Furthermore, pore size distribution, molecular weight cut-off (MWCO) and porosity were also researched to evaluate the MMM. The dislodge of Reactive Black KN-B, Reactive Red 3BS and Reactive Brilliant Blue KN-R dyes by MMM were studied under different dye concentrations and transmembrane pressures. The membrane can provide selective separation methods for dyes and Reactive Brilliant Blue KN-R up to 99%. Overall, the permeability, hydrophilicy, anti-fouling performance and wastewater treatment of modified membranes were regulated by the ZIF-8 in a steerable blending reaction modification process.

scholarly journals Porous Gelatin Membranes Obtained from Pickering Emulsions Stabilized with h-BNNS: Application for Polyelectrolyte-Enhanced Ultrafiltration

Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 144 ◽  
Author(s):  
Molka Nafti Mateur ◽  
Danae Gonzalez Ortiz ◽  
Dorra Jellouli Ennigrou ◽  
Karima Horchani-Naifer ◽  
Mikhael Bechelany ◽  
...  
Keyword(s):  
Pore Size ◽  
Water Permeability ◽  
Hexagonal Boron Nitride ◽  
Pure Water ◽  
Transmembrane Pressure ◽  
Pickering Emulsions ◽  
Drying Time ◽  
Membrane Pore ◽  
Membrane Pore Size ◽  
Water Swelling

In recent years, numerous studies have been conducted to develop biopolymer-based membranes, highlighting the challenges to prepare porous structures with control porosity. In this paper an innovative method that relies on the generation of Pickering emulsions was developed to prepare porous membranes from gelatin for filtration purpose. Hexagonal boron nitride nanosheets (h-BNNS) were used to stabilize micro-droplets of castor oil in a continuous homogeneous gelatin solution. Two steps in the membrane preparation process strongly influenced the porous structure. Specifically, the duration of the drying time after emulsion casting and the duration of the cross-linking step affected membrane pore size, hydrophobicity, water swelling, and water permeability. By controlling these two steps, membranes could be designed with pore size between 0.39 and 1.60 μm and display pure water permeability between 150 and 506 L h−1 m−2 bar−1. These membranes have been tested for complexation–ultrafiltration experiments in which iron ions were removed from aqueous solutions with/without poly (acrylic acid) (PAA). Without PAA, the removal of free iron (II) ions was low (not more than 14%). The addition of PAA (200 ppm) allowed obtaining high removal rates (97%) at pH ≥ 5 with 3 bars of transmembrane pressure.

Fabrication Membrane of Titanium dioxide (TiO2) Blended Polyethersulfone (PES) and Polyvinilidene fluoride (PVDF): Characterization, Mechanical Properties and Water Treatment

2020 ◽  
Vol 867 ◽  
pp. 159-165
Author(s):  
Agung Mataram ◽  
Nyanyu Anisya ◽  
Nyayu Ayu Nadiyah ◽  
Afriansyah
Keyword(s):  
Mechanical Properties ◽  
Titanium Dioxide ◽  
Water Treatment ◽  
Electric Field ◽  
Polyvinylidene Fluoride ◽  
Membrane Surface ◽  
Pure Water ◽  
Permeate Flux ◽  
Field Methods ◽  
Membrane Pore

In this research, Polyethersulfone (PES) and Polyvinylidene Fluoride (PVDF) with the addition of a Titanium Dioxide (TiO2) blanded membrane were prepared using the DC 15000 V electric field method. The investigation of this research is the adding result of Titanium Dioxide (TiO2) with the DC 15000 V electric field methos such as the mechanical properties of membranes and water treatment performance. The surface mixture of Polyethersulfone (PES) and Polyvinylidene Fluoride (PVDF) membranes is characterized using SEM, the membrane pore size shrinks and forms evenly with the addition of Titanium Dioxide (TiO2) and DC electric field methods. Tensile tests were carried out to obtain the mechanical properties of Polyethersulfone (PES) and Polyvinylidene Fluoride (PVDF) by adding Titanium Dioxide (TiO2) mixture membrane, which showed an increase in optimal tensile strength to 3.86 MPa at a concentration of 30% Polyethersulfone (PES) and also increased to 1.15 MPa at 20% Polyvinylidene Fluoride (PVDF). The membrane surface was examined using contact angle measurements, which in the mixed membrane Polyethersulfone (PES) and Polyvinylidene Fluoride (PVDF) showed a decrease in the angle between the range of 43o - 46o. Therefore, hydrophilicity makes it possible to suppress the permeate flux of pure water. Making membranes with the addition of Titanium Dioxide (TiO2), and assisted by DC electric fields opens up new ways to increase membrane strength, hydrophilicity, shrink and make pore sizes evenly formed.

Studies on the Relationship between Morphology and Water Flux of PVDF/PU Blend Membranes

2011 ◽  
Vol 121-126 ◽  
pp. 387-391
Author(s):  
Guo Lan Huan ◽  
Jian Li Liu ◽  
Qi Yun Du ◽  
Xiao Yu Hu
Keyword(s):  
Cross Section ◽  
Polyvinylidene Fluoride ◽  
Fractal Theory ◽  
Membrane Surface ◽  
Water Flux ◽  
Precipitation Process ◽  
Blend Membrane ◽  
Blend Membranes ◽  
Operation Pressure ◽  
The Relationship

Polyvinylidene fluoride/polyurethane (PVDF/PU) blend membranes were made via immersion precipitation process, the surface morphologies and the micro-porous structures of the blend membranes were analyzed using scanning electronic microscope (SEM) and fractal theory, the water flux change with the operation pressure of the blend membranes was investigated, and the relationship between blend membrane morphology and water flux was discussed. The results showed that, the water flux of the resulting blend membranes was increased, and the contribution of different structures to water flux was in the following order: cross-section finger-shaped porous defects > cross-section through holes > blend membrane surface pores. In addition, water flux of the blend membranes was also related to the deformability of PU.

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