PHASE INVERSION PREPARATION AND MORPHOLOGICAL STUDY OF POLYVINYLIDENE FLUORIDE ULTRAFILTRATION MEMBRANE MODIFIED BY NANO-SIZED ALUMINA

In this study, polyvinylidene fluoride (PVDF) membranes with various structures ranging from dense to highly asymmetric morphologies were obtained by changing the effective parameters in the phase inversion process. The effect of some important processing parameters such as solution concentration, harshness of the precipitation bath, exposure time before immersion in coagulation bath and bath temperature was studied and the mentioned parameters were optimized. The membranes were then modified with nano-sized alumina powder in order to improve the hydrophilicity of the PVDF membranes. The surface morphology, surface and cross-sectional structures of the membranes were examined by scanning electron microscope (SEM) and atomic force microscope (AFM). The specific surface area of the membranes was determined using the Brunauer–Emmett–Teller (BET) method. The contact angles between water and the membranes' surfaces were measured in order to study the hydrophilicity changes of the membrane surface. The results indicated that the addition of nano-sized alumina to the casting dope increased the hydrophilicity of the PVDF membrane surface.

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Preparation of hydrophilic modified polyvinylidene fluoride (PVDF) ultrafiltration membranes by polymer/non-solvent co-induced phase separation: effect of coagulation bath temperature

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0245 ◽

2022 ◽

Vol 0 (0) ◽

Author(s):

Xiaoming Zhang ◽

Qingchen Lu ◽

Nana Li

Keyword(s):

Phase Separation ◽

Membrane Fouling ◽

Membrane Structure ◽

Polyvinylidene Fluoride ◽

Membrane Surface ◽

Pure Water ◽

Bath Temperature ◽

Coagulation Bath ◽

Separation Performance ◽

Coagulation Bath Temperature

Abstract Membrane separation technology is widely used in wastewater purification, but the issue of membrane fouling could not be ignored. Hydrophilic modification is an effective method to reduce membrane fouling. Therefore, in this work, a hydrophilic modified polyvinylidene fluoride (PVDF) ultrafiltration membrane was prepared by polymer/non-solvent co-induced phase separation, and the effect of coagulation bath temperature on the membrane structure and performance was systematically investigated based on the previous study. With the increased of the coagulation bath temperature, the phase separation process changed from delayed to instantaneous, and the membrane surface changed from porous to dense, while the macropore structures and sponge-like pores appeared on the cross-section. Meanwhile, the pure water flux decreased from 229.3 L/(m2·h) to 2.08 L/(m2·h), the protein rejection rate increased from 83.87% to 100%, and the surface water contact angle increased from 63° to 90°. Thus, excessively high coagulation bath temperature adversely affected the permeate and separation performance, as well as antifouling performance of the membrane. This study enriched the research for preparing separation membranes by polymer/non-solvent co-induced phase separation and provided a practical and theoretical reference for controlling the membrane structure and properties by changing the coagulation bath temperature.

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

Water Science & Technology Water Supply ◽

10.2166/ws.2018.187 ◽

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.

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

Water Science & Technology Water Supply ◽

10.2166/ws.2020.068 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1629-1642 ◽

Cited By ~ 1

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.

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Effect of sonochemical synthesized TiO2 nanoparticles and coagulation bath temperature on morphology, thermal stability and pure water flux of asymmetric cellulose acetate membranes prepared via phase inversion method

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq111202014a ◽

2012 ◽

Vol 18 (3) ◽

pp. 385-398 ◽

Cited By ~ 20

Author(s):

Reza Abedini ◽

Mahmoud Mousavi ◽

Reza Aminzadeh

Keyword(s):

Thermal Stability ◽

Tio2 Nanoparticles ◽

Phase Inversion ◽

Pure Water ◽

Water Flux ◽

Composite Membranes ◽

Bath Temperature ◽

Coagulation Bath ◽

Pure Water Flux ◽

Coagulation Bath Temperature

In this study, asymmetric pure CA and CA/ TiO2 composite membranes were prepared via phase inversion by dispersing TiO2 nanopaticles in the CA casting solutions induced by immersion precipitation in water coagulation bath. TiO2 nanoparticles, which were synthesized by the sonochemical method, were added into the casting solution with different concentrations. Effects of TiO2 nanoparticles concentration (0 wt. %, 5wt.%, 10wt.%, 15wt.%, 20wt.% and 25wt.%) and coagulation bath temperature (CBT= 25?C, 50?C and 75?C) on morphology, thermal stability and pure water flux (PWF) of the prepared membranes were studied and discussed. Increasing TiO2 concentration in the casting solution film along with higher CBT resulted in increasing the membrane thickness, water content (WC), membrane porosity and pure water flux (PWF), also these changes facilitate macrovoids formation. Thermal gravimetric analysis (TGA) shows that thermal stability of the composite membranes were improved by the addition of TiO2 nanopaticles. Also TGA results indicated that increasing CBT in each TiO2 concentration leads to the decreasing of decomposition temperature (Td) of hybrid membranes.

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Fabrication and Characterization of GO-Fe3O4/PSF Membrane with Phase Inversion Method

JPSE (Journal of Physical Science and Engineering) ◽

10.17977/um024v6i22021p055 ◽

2021 ◽

Vol 6 (2) ◽

pp. 55-60

Author(s):

Vivia Maulida Alfianti ◽

◽

Munasir Munasir ◽

Keyword(s):

Phase Inversion ◽

Average Pore Size ◽

Membrane Surface ◽

Xrd Analysis ◽

Solid Matrix ◽

Coagulation Bath ◽

Inversion Method ◽

Average Pore ◽

Polysulfone Membrane ◽

Phase Inversion Method

Polysulfones are hydrophobic which can reduce membrane permeability. Permeability can be increased through the application of hydrophilic materials such as GO-Fe3O4 to the polysulfone membrane so that the membrane is hydrophilic. The riset purpose to determine the effect of the percentage weight of different material compositions on the hydrophilicity properties of the polysulfone membrane. Membrane fabrication is carried out using the phase inversion method where the polymer solution is molded in a place and immersed in a coagulation bath containing non-solvent. This solvent exchange causes the polymer to form a solid matrix and become a membrane. The results showed that GO particles were successfully doped with Fe3O4 material shown by XRD analysis at a peak of 35.61˚ with a magnetite phase, while FTIR analysis showed that there was an absorption band characteristic of Fe-O streching vibrations. The results of the contact angle test on the GO-Fe3O4/PSF membrane 0.75 wt per cent were around 73.17˚ which showed the smallest hydrophobic value and the membrane surface morphology had an average pore size of 333.61 nm so that the addition of GO-Fe3O4 composites could increase membrane hydrophilicity.

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The Effect of Temperature, Sulfonation, and PEG Addition on Physicochemical Characteristics of PVDF Membranes and Its Application on Hemodialysis Membrane

Indonesian Journal of Chemistry ◽

10.22146/ijc.63740 ◽

2021 ◽

Vol 21 (4) ◽

pp. 942

Author(s):

Retno Ariadi Lusiana ◽

Ayub Indra ◽

Nor Basid Adiwibawa Prasetya ◽

Nurwarrohman Andre Sasongko ◽

Parsaoran Siahaan ◽

...

Keyword(s):

Membrane Permeability ◽

Water Uptake ◽

Polyvinylidene Fluoride ◽

Bath Temperature ◽

Physicochemical Characteristics ◽

Effect Of Temperature ◽

Coagulation Bath ◽

Pvdf Membrane ◽

Swelling Degree ◽

Ft Ir

Polyvinylidene fluoride (PVDF) membrane and its derivative have been investigated the permeation ability for creatinine and urea. The membrane was made by an inversion precipitation system in N,N-dimethyl acetamide (DMAc) and water as non-solvents. In this study, the modification of PVDF membrane permeability with PEG additives, CBT variations, and sulfonation was successfully carried out. The membrane solidification process was carried out on three variations of the coagulation bath temperature (CBT): 30, 45, and 60 °C. Eight types of membranes were characterized by using FT-IR and TGA/DSC, followed by the analysis of their porosity, hydrophilicity, water uptake, swelling degree, tensile strength, and permeability of creatinine and urea. The FT-IR spectra indicate that PVDF modification has been successfully carried out. The porosity, hydrophilicity, water uptake, and swelling degree values increase with the modification of functional groups. Furthermore, improvements in creatinine and urea permeability and clearances are achieved by increasing CBT and sulfonation in the PVDF/PEG membrane. The presence of sulfonate groups improves the membrane permeability through the interaction of intermolecular hydrogen with water and dialysate compounds. The existence of PEG as a porogen enhanced membrane porosity. Creatinine and urea clearance values increase from 0.29–0.58 and 6.38–20.63 mg/dL, respectively.

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A Wet-Spinning Process for Producing Carbon Nanotube/Polyvinylidene Fluoride Fibers Having Highly Consistent Electrical and Mechanical Properties

Polymers ◽

10.3390/polym13224048 ◽

2021 ◽

Vol 13 (22) ◽

pp. 4048

Author(s):

Ki-Weon Kang ◽

Chan-Woong Choi ◽

Ji-Won Jin

Keyword(s):

Carbon Nanotube ◽

Polyvinylidene Fluoride ◽

Structural Variation ◽

Initial Conditions ◽

Bath Temperature ◽

Wet Spinning ◽

Longitudinal Variation ◽

Cross Sectional ◽

Spinning Process ◽

Dope Solution

Studies of polymer/carbon nanotube (CNT) fibers typically focus on optimizing the overall properties, and the effects of structural variation on these properties are ignored. Thus, we investigated the longitudinal variation in the properties of CNT/polyvinylidene fluoride (CNT/PVDF) fibers prepared by wet spinning a solution of multi-walled nanotubes, PVDF, and dimethylacetamide. To this end, materials for the CNT/PVDF fiber were selected, and a dope solution was prepared using MWNT, PVDF, and dimethylacetamide (DMAc). To consider the process parameters that would affect the performance of the CNT/PVDF fiber during the wet-spinning process using the dope solution, the initial conditions for wet spinning were selected, including bath concentration, bath temperature, drying temperature, and elongation, and the CNT/PVDF fiber was spun under the corresponding conditions. Additionally, three performance stabilization processes were proposed to improve the initial conditions for wet spinning and manufacturing the fiber. Lastly, to confirm the reliability of the CNT/PVDF fiber in all sections, tensile strength, electrical conductivity, and cross-sectional images were analyzed for the 30 m, 60 m, and 90 m sections of the fiber, and the reliability of the wet-spinning process was verified.

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Development of antimicrobial and antifouling nanocomposite membranes by a phase inversion technique

Journal of Polymer Engineering ◽

10.1515/polyeng-2019-0007 ◽

2019 ◽

Vol 39 (6) ◽

pp. 545-555 ◽

Cited By ~ 1

Author(s):

Zeenat Arif ◽

Naresh Kumar Sethy ◽

Lata Kumari ◽

Pradeep Kumar Mishra ◽

Bhawna Verma

Keyword(s):

Polyvinylidene Fluoride ◽

Phase Inversion ◽

High Efficiency ◽

Separation Efficiency ◽

Membrane Surface ◽

Experimental Result ◽

Major Drawback ◽

E Coli ◽

Inversion Technique ◽

Phase Inversion Technique

Abstract Membrane separation technology is preferred over conventional techniques because of its simple operation and high efficiency. The major drawback of using a pristine polymer for membrane application includes its rapid fouling tendency, which affects the separation efficiency of membranes; hence, they need to be modified using physical or chemical techniques. Recent developments involve the incorporation of nanoparticles within the polymer to achieve high efficiency along with stability. The hydrophobic membranes of polyvinylidene fluoride (PVDF) blended with titanium dioxide (TiO2) nanoparticles were synthesized using a phase inversion technique to develop an antifouling membrane. The effects of TiO2 loading on the permeation flux and antimicrobial behavior of the membranes were systematically investigated, and the experimental results were also justified using the theoretical model. Extended Derjaguin–Landau–Verwey–Overbeek, high-resolution scanning electron microscopy, and atomic force microscopy were used to study the membrane morphology. It was observed that the antimicrobial properties of different PVDF/TiO2 ratios against Gram-negative Escherichia coli (E. coli) showed excellent results compared with PVDF membrane. The antimicrobial activity was also evaluated to study the exponential growth phases’ retardation of E. coli over the membrane surface. The experimental result for bovine serum albumin filtration was also studied and high protein rejection was achieved for PVDF/TiO2 (1.5 wt%) membrane.

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A novel positively charged membrane based on polyamide thin-film composite made by cross-linking for nanofiltration

Water Science & Technology ◽

10.2166/wst.2015.538 ◽

2015 ◽

Vol 73 (4) ◽

pp. 776-789 ◽

Cited By ~ 3

Author(s):

Ahmad Akbari ◽

Zahra Fakharshakeri ◽

Sayed Majid Mojallali Rostami

Keyword(s):

Interfacial Polymerization ◽

Membrane Surface ◽

Water Flux ◽

Feed Solution ◽

Contact Angles ◽

Cross Linking ◽

Cross Sectional ◽

Charged Membrane ◽

Trimesoyl Chloride ◽

Positively Charged

In this paper, a novel positively charged membrane was prepared through interfacial polymerization technique between polyethyleneimine in aqueous phase and trimesoyl chloride in organic phase. Next, cross-linking of polyamide (PA) layer using ρ-xylylene dichloride (XDC) and glutaraldehyde (GA) was studied. The influences of cross-linking concentrations on the separation and permeation performance of membrane were also investigated. Membranes were characterized in terms of their chemical structure, the cross-sectional and surface morphologies, contact angles, molecular weight cut-off (MWCO) and effect of pH feed solution. The salt rejection sequence of CaCl2 >NaCl > Na2SO4 showed a positive charge at the membrane surface after cross-linking reaction. The MWCO of primary PA membrane decreased from 1,135 to 775 and 885 Da for XDC and GA, respectively. XDC membrane shows highest CaCl2 divalent cationic rejection (95.5%) and lowest water flux (21.1 L/m2.h). This study illustrates a promising method for fabrication of positively charged membrane in cation separation.

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Modification of the Surface Morphology and Properties of Graphene Oxide and Multi-Walled Carbon Nanotube-Based Polyvinylidene Fluoride Membranes According to Changes in Non-Solvent Temperature

Nanomaterials ◽

10.3390/nano11092269 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2269

Author(s):

Jungryeong Chae ◽

Taeuk Lim ◽

Hao Cheng ◽

Wonsuk Jung

Keyword(s):

Graphene Oxide ◽

Functional Groups ◽

Polyvinylidene Fluoride ◽

Water Flux ◽

Bath Temperature ◽

Coagulation Bath ◽

Water Contact ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Pure Pvdf

The effect of changes in non-solvent coagulation bath temperature on surface properties such as morphology and hydrophilicity were investigated in multi-walled carbon nanotubes (MWCNTs) and graphene oxide (GO)-based polyvinylidene fluoride (PVDF) membranes. The properties of pores (size, shape, and number) as well as membrane hydrophilicity were investigated using field emission scanning electron microscopy, Raman spectroscopy, optical microscopy, water contact angle, and water flux. Results showed that the pore size increased with an increase in coagulation temperature. The hydrophilic functional groups of the added carbon materials increased the solvent and non-solvent diffusion rate, which significantly increased the number of pores by 700% as compared to pure PVDF. Additionally, these functional groups changed the hydrophobic properties of pure PVDF into hydrophilic properties.

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