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 ◽  
...  

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.

2018 ◽  
Vol 19 (4) ◽  
pp. 1279-1285
Author(s):  
Q. Y. Zhang ◽  
Q. An ◽  
Y. G. Guo ◽  
J. Zhang ◽  
K. Y. Zhao

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.


2014 ◽  
Vol 70 (2) ◽  
Author(s):  
H. P. Ngang ◽  
A. L. Ahmad ◽  
S. C. Low ◽  
B .S. Ooi

In the present work, polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes were prepared by diffusion induced phase separation process (DIPS). N,N’-dimethylformamide (DMF) was used as the solvent and water was used as coagulant. The effect of polyethylene glycol (PEG 2000) concentration in the casting solution on morphology and performance were investigated. The physical properties of PVDF UF membranes were characterized based on pore size distribution, scanning electron microscope (SEM) and contact angle. The permeation performance of the membranes were evaluated in term of pure water flux (PWF), relative flux reduction (RFR), flux recovery ratio (FRR), and bovine serum albumin (BSA) rejection. The pore size distribution increased with the increased in PEG 2000 concentrations, and pure water flux also increased accordingly. The PEG 2000 at concentration of 6 wt.% achieved lowest RFR (50.38%), highest FRR (84.54%) and achieved highest BSA rejection, of 94.55%. This membrane exhibited better antifouling properties as well as improved membrane performance during filtration of BSA due to the optimum pore size, hydrophilic as well as smooth surface. 


2011 ◽  
Vol 480-481 ◽  
pp. 201-206
Author(s):  
Li Guo Wang ◽  
Xiu Ju Wang ◽  
Ai Min Wang ◽  
Wen Juan Liu ◽  
Shi Qi Guo ◽  
...  

Hydrophilic Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membranes were prepared by wet-spinning method. The effects of technical parameters of acrylic acid grafted onto PVDF on the performance of hydrophilic PVDF membranes were investigated via orthogonal test, the technical parameters of preparation of hydrophilic PVDF membranes were determined, and hydrophilic PVDF membranes were prepared. Then hydrophilic PVDF membranes were characterized in terms of breaking strength, breaking elongation, rupture pressure, pure water flux and rejection. The fouling properties and the conditions of acrylic acid grafted onto PVDF were also examined. The results showed that acrylic acid had been grafted onto PVDF, the breaking strength and rupture pressure improved greatly, and the fouling properties were better than PS hollow fiber UF membrane.


2017 ◽  
Vol 79 (1-2) ◽  
Author(s):  
Siti Khadijah Hubadillah ◽  
Mohd Hafiz Dzarfan Othman ◽  
A. F. Ismail ◽  
Mukhlis A. Rahman ◽  
Juhana Jaafar

Ceramic hollow fibre membrane (CHFM) demonstrated superior characteristics and performance in any separation application. The only problem associated with this kind of technology is the high cost. In order to effectively fabricate and produce low cost porous CHFM, a series of CHFMs made of kaolin were fabricated via combined phase inversion and sintering technique. The CHFMs from kaolin named as kaolin hollow fibre membranes (KHFMs) were studied at different kaolin contents of 35 wt.%, 37.5 wt.% and 40 wt.% sintered at 1200ºC. The result indicated that by varying kaolin contents, different morphologies were obtained due to changes in the viscosity of ceramic suspension containing kaolin. The optimum kaolin content for KHFM was identified. It was found that KHFM prepared at 37.5 wt% has a mechanical strength and pure water flux of A and B respectively.  


2011 ◽  
Vol 295-297 ◽  
pp. 286-291
Author(s):  
Li Guo Wang ◽  
Xiao Guang Zhang ◽  
Shu Fang Hou ◽  
Xiu Ju Wang ◽  
Ai Min Wang ◽  
...  

Hydrophilic polyvinylidene fluoride (PVDF) flat ultrafiltration membranes were prepared by wet-spinning method. The effects of technical parameters of maleic anhydride grafted onto PVDF on the performance of hydrophilic PVDF membranes were investigated, the preparation technical parameters were determined, and the hydrophilic PVDF flat membranes were prepared. Then, hydrophilic PVDF membranes were characterized in terms of pure water flux, contact angle, infrared spectroscopic analysis and scanning electron microscope(SEM). The results showed that maleic anhydride had been grafted onto PVDF, and the hydrophilic performance of the modified membrane was better than the traditional one.


2012 ◽  
Vol 528 ◽  
pp. 210-213 ◽  
Author(s):  
Xuan Wang ◽  
Hao Long Bai ◽  
Li Ping Zhang

Nanocrystalline cellulose was used to blend with polysulfone to improve the hydrophicility and mechanical properties of PS hollow fiber ultrafiltration membrane. The method of dry-jet/wet-spining was adopted to form the hollow fiber by the mechanism of phase-inversion. In addition, the content of NCC was increased gradually from 0% to 1 wt% to examin the permeation flux, rejection ratio of bovine serum albumin(BSA) and mechanical strength of PS hollow-fiber. We find that the pure water flux was soared when NCC content was increased. The tensile strength and elongation at break were also detected and calculated. The results indicated that the properties of PS hollow-fiber membrane with appropriate NCC content were enhanced. The hollow fiber membranes were also observed with scaning electron microscopy(SEM) to explore the porous structure


2021 ◽  
pp. 1-8
Author(s):  
Jiale Qu ◽  
Shen Gao ◽  
Zhenghao Hou

Polyvinylidene fluoride (PVDF) is a promising membrane material in ultrafiltration (UF) applications; its extensive application however is limited due to the disadvantage in hydrophilicity and low surface energy. Herein, a sort of TPU-modified PVDF membrane is prepared by blending method and its hydrophilicity is compared with a series of pure/modified PVDF membranes. The contact angle and pure water flux (PWF) results demonstrate that the hydrophilicity of the TPU-modified PVDF membrane is enhanced, and the performance is not inferior to that of traditional pore-modified PVDF membranes. SEM image shows that the TPU-modified PVDF membrane maintains morphology of the pure PVDF membrane, indicating that TPU molecules have excellent compatibility with PVDF molecules and can maintain the mechanical property of PVDF membrane to a certain extent. Finally, we explore the effects of TPU molecules and PVDF molecules on water molecules, respectively, from a microscopic perspective involving first principles. This investigation not only establishes that PVDF membrane has been prepared with enhanced hydrophilicity, but also provides a novel avenue for the modification of membrane properties.


2015 ◽  
Vol 74 (11) ◽  
Author(s):  
Azizul Mohd Zahari ◽  
Abdull Rahim Mohd Yusoff ◽  
Nor Aziah Buang ◽  
Palanivel Satishkumar ◽  
M Jasmin Fathi Jasni ◽  
...  

This research is about the investigation of the pure water flux property of composite polyvinylidene fluoride (PVDF) nanofibers. Electrospinning technique was used to prepare the composite electrospun nanofibers. PVDF was dissolved in N,N-dimethylformamide (DMF) solvent and blended together with activated carbon (AC) and polyvinylpyrrolidone (PVP). The nanofibers were characterized to determine the morphologies, wettability property, and its tensile strength. The fabricated nanofibers diameter was found in the range between 20 to 180 nm. The presence of AC deteriorates the mechanical properties of the nanofibers as the size of AC is larger than the external diameter of the nanofibers. The results of contact angle confirmed that the fabricated nanofiber exhibit less hydrophobic in the presence of PVP and AC. The less hydrophobic nature of proposed nanofiber might be useful for the water treatment process.


2012 ◽  
Vol 18 (3) ◽  
pp. 385-398 ◽  
Author(s):  
Reza Abedini ◽  
Mahmoud Mousavi ◽  
Reza Aminzadeh

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.


2021 ◽  
Author(s):  
Parya Hasanzade ◽  
Parvin Gharbani ◽  
Fahime Derakhshan ◽  
Behnaz Memar Maher

Abstract Polyvinylidene fluoride (PVDF)/g-C3N4/Chitosan thin film membranes were prepared for removal of Direct Blue 14 dye (an anionic dye) from aqueous solutions. PVDF/g-C3N4/Chitosan membranes were prepared by immersing of PVDF/g-C3N4 membrane in solution containing various concentrations of chitosan. The resulting membranes were characterized by XRD, FESEM, TEM and AFM. Also, pure water flux, salt rejection, water content, antifouling properties of prepared membranes were investigated. The resulting demonstrate that pure water flux was decreased by increasing of chitosan concentration, while water content, antifouling properties and salt rejection were increased. It is found that chitosan has major impact on the membrane structural properties due to transform of the PVDF membrane into hydrophilic ones. It is reported that maximum 93% rejection of Direct Blue 14 was obtained by PVDF/g-C3N4/Chitosan membrane. Compared to the PVDF/g-C3N4 membrane, the experimental results showed that PVDF/g-C3N4/Chitosan membranes demonstrated high potential mainly due to greater hydrophilicity and further minimizing membrane fouling.


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