scholarly journals Inner Surface Hydrophilic Modification of PVDF Membrane with Tea Polyphenols/Silica Composite Coating

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4186
Author(s):  
Qiang Xu ◽  
Xiaoli Ji ◽  
Jiaying Tian ◽  
Xiaogang Jin ◽  
Lili Wu
Keyword(s):  
Composite Coating ◽  
Polyvinylidene Fluoride ◽  
Water Flux ◽  
Tea Polyphenols ◽  
Pvdf Membrane ◽  
Hydrophilic Modification ◽  
Silica Composite ◽  
Inner Surface ◽  
One Step ◽  
Modified Membrane

The use of Polyvinylidene fluoride (PVDF) membranes is constrained in wastewater treatment because of their hydrophobic nature. Therefore, a large number of researchers have been working on the hydrophilic modification of their surfaces. In this work, a superhydrophilic tea polyphenols/silica composite coating was developed by a one-step process. The composite coating can achieve not only superhydrophilic modification of the surface, but also the inner surface of the porous PVDF membrane, which endows the modified membrane with excellent water permeability. The modified membrane possesses ultrahigh water flux (15,353 L·m−2·h−1). Besides this, the modified membrane can realize a highly efficient separation of oil/water emulsions (above 96%).

Preparation and Characterization of PVDF Modified Ultrafiltration Membrane for Purification of Hg in Water

2013 ◽  
Vol 575-576 ◽  
pp. 265-269 ◽  
Author(s):  
Xiu Ju Wang ◽  
Xing Jie Lu ◽  
Wei Ying Xu ◽  
Jia Chen Zhu ◽  
Li Guo Wang
Keyword(s):  
Polyvinylidene Fluoride ◽  
Retention Rate ◽  
Water Flux ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Ultrafiltration Membrane ◽  
Mercury Ion ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Modified Membrane

The 2-thiol benzothiazole was blended in Polyvinylidene fluoride (PVDF) membrane to prepare a kind of PVDF modified ultrafiltration membrane that could be used to remove mercury ion in water treatment. The water flux and retention rate of BSA of obtained PVDF modified ultrafiltration membrane was 222 L/m2·h and 92.33% respectively. The membrane performance were characterized by infrared spectroscopy (FT-IR) and water contact angle measurement. The results showed that, the PVDF modified membrane presented better adsorption ability for mercury ion than the traditional PVDF membrane. After 4 phases of adsorption/desorption, the modified membrane maintained a mercury ion adsorption amount of 0.264 mg/cm2and the desorption rate could reached 94%.

Hydrophilic modification of PVDF membranes by in situ synthesis of nano-Ag with nano-ZrO2

2021 ◽  
Vol 10 (1) ◽  
pp. 538-546
Author(s):  
Yanjun Lu ◽  
Yuxuan Ma ◽  
Tong Yang ◽  
Jifeng Guo
Keyword(s):  
Polyvinylidene Fluoride ◽  
Pure Water ◽  
Water Flux ◽  
Inversion Method ◽  
Hydrophilic Modification ◽  
E Coli ◽  
Pure Water Flux ◽  
Modified Membrane ◽  
Phase Inversion Method

Abstract Modified polyvinylidene fluoride (PVDF) membranes were prepared by the phase inversion method via blending in situ formed nanosilver (Ag) and nanozirconium dioxide (ZrO2). Scanning electron microscopy of the membranes revealed that the surface pore size of the membranes was increased and distributed widely with the addition of modified nanosilver (Ag) and nanozirconium dioxide (ZrO2). The pores of the membrane were reduced due to excessive modification of the material when the content of zirconium dioxide was increased to 0.4%. XRD characterization showed that in situ synthesis of nanosilver (Ag) and nanozirconium dioxide (ZrO2) had been successfully blended in the membranes. The contact angle of the modified membrane ranged from 82.72° to 67.37°, which showed that the hydrophilic properties of the membrane were improved. The pure water flux of the modified membrane increased from 28.43 to 143.2 L/m2 h, indicating that the hydrophilicity of the modified membrane was enhanced significantly. The flux recovery rate of the modified membrane was obviously increased in the fouling experiment with BSA as the source of organic pollutants. The antimicrobial contamination of the membrane was greatly enhanced with the E. coli microbial contamination experiment.

Effect of Nano-Sized ZnO Particle Addition on PVDF Ultrafiltration Membrane Performance

2011 ◽  
Vol 311-313 ◽  
pp. 1818-1821 ◽  
Author(s):  
Yang He ◽  
Jun Ming Hong
Keyword(s):  
Aqueous Solution ◽  
Polyvinylidene Fluoride ◽  
Tensile Elongation ◽  
Water Flux ◽  
Reclaimed Water ◽  
Oxygen Demand ◽  
Inversion Method ◽  
Permeation Flux ◽  
Pvdf Membrane ◽  
Modified Membrane

In this study, a polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane was modified by dispersing nano-sized ZnO particles in a PVDF solution. PVDF membranes were fabricated by a phase inversion method. The permeation flux, mechanical properties, rejection of BSA aqueous solution and reclaimed water treatment were examined. The results indicate that the permeation flux of the modified membrane was lower than the neat PVDF membrane. The maximum tension force and tensile elongation length were improved initially for the modified membrane. The rejection of BSA aqueous solution was improved to 98.4%, while the neat PVDF membrane was 87.26%, and the relative water flux reduction was lower than the neat PVDF membrane. The chemical oxygen demand (COD) removal of the reclaimed water treated by the modified membrane was 46.36%, while the neat PVDF membrane was 14.09%.

scholarly journals The Modification of PVDF Membrane via Crosslinking with Chitosan and Glutaraldehyde as the Crosslinking Agent

2018 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
Romaya Sitha Silitonga ◽  
Nurul Widiastuti ◽  
Juhana Jaafar ◽  
Ahmad Fauzi Ismail ◽  
Muhammad Nidzhom Zainol Abidin ◽  
...  
Keyword(s):  
Contact Angle ◽  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Pure Water ◽  
Water Flux ◽  
Crosslinking Agent ◽  
Hydrophobic Properties ◽  
Pvdf Membrane ◽  
Pure Water Flux ◽  
Modified Membrane

Poly(vinylidene fluoride) (PVDF) has outstanding properties such as high thermal stability, resistance to acid solvents and good mechanical strength. Due to its properties, PVDF is widely used as a membrane matrix. However, PVDF membrane is hydrophobic properties, so as for specific applications, the surface of membrane needs to be modified to become hydrophilic. This research aims to modify PVDF membrane surface with chitosan and glutaraldehyde as a crosslinker agent. The FTIR spectra showed that the modified membrane has a peak at 1655 cm-1, indicating the imine group (–N=C)- that was formed due to the crosslink between amine group from chitosan and aldehyde group from glutaraldehyde. Results showed that the contact angle of the modified membrane decreases to 77.22° indicated that the membrane hydrophilic properties (< 90°) were enhanced. Prior to the modification, the contact angle of the PVDF membrane was 90.24°, which shows hydrophobic properties (> 90°). The results of porosity, Ɛ (%) for unmodified PVDF membrane was 55.39%, while the modified PVDF membrane has a porosity of 81.99%. Similarly, by modifying the PVDF membrane, pure water flux increased from 0.9867 L/m2h to 1.1253 L/m2h. The enhancement of porosity and pure water flux for the modified PVDF membrane was due to the improved surface hydrophilicity of PVDF membrane.

Preparation and Characterization of Hydrophilic PVDF Membrane via Graft Modification by Maleic Anhydride

2011 ◽  
Vol 295-297 ◽  
pp. 286-291
Author(s):  
Li Guo Wang ◽  
Xiao Guang Zhang ◽  
Shu Fang Hou ◽  
Xiu Ju Wang ◽  
Ai Min Wang ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Polyvinylidene Fluoride ◽  
Pure Water ◽  
Water Flux ◽  
Pvdf Membrane ◽  
Technical Parameters ◽  
Pure Water Flux ◽  
Flat Membranes ◽  
Better Than

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.

scholarly journals The influences of polydopamine immersion time on characteristics and performance of polyvinylidene fluoride ultrafiltration membrane

2018 ◽  
Vol 197 ◽  
pp. 09007
Author(s):  
Syawaliah Syawaliah ◽  
Nasrul Arahman ◽  
Medyan Riza ◽  
Sri Mulyati
Keyword(s):  
Polyvinylidene Fluoride ◽  
Water Flux ◽  
Sem Analysis ◽  
Inversion Method ◽  
Asymmetric Structure ◽  
Pvdf Membrane ◽  
Before And After ◽  
Poly Ethylene ◽  
And Performance ◽  
Phase Inversion Method

The Polyvinylidene Fluoride (PVDF) membrane has been prepared by phase inversion method using N,N-dimethylacetamide (DMAc) as solvent and Poly Ethylene Glycol (PEG) as additive. The fabricated membrane was modified by Polydopamine (PDA) coating in concentration of 0.5 mg/ml and immersion times of 2 hours, 6 hours, and 24 hours. The characteristics and performance of the PVDF membranes before and after the modification are studied in this paper. The result of the water flux experiment showed that the PDA-coated PVDF membranes showcased a higher flux than that of pure PVDF membrane. Scanning Electron Microscopy (SEM) analysis confirmed that the membrane had an asymmetric structure consisting of two layers. There was no significant influence on the addition of PDA to the morphology of the pore matrix because the modification was done by surface coating. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that PDA was successfully introduced on the surface of PVDF membrane with the appearance of O-H from cathecol and N-H peaks at wavenumber range of 3300-3600 cm-1. Modification with PDA increased the mechanical strength of the membrane which affirmed by the results of the tensile and elongation at break evaluation.

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.

Novel Nanoparticles Incorporated Polyvinylidene Fluoride Ultrafiltration Membrane

2013 ◽  
Vol 746 ◽  
pp. 390-393
Author(s):  
Qiong Zhi Gao ◽  
Hong Qiang Li ◽  
Xing Rong Zeng
Keyword(s):  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Water Flux ◽  
Silver Ions ◽  
Inversion Method ◽  
Hybrid Films ◽  
Ultrafiltration Membranes ◽  
Pvdf Membrane ◽  
Basic Performance ◽  
Phase Inversion Method

In this study, polyvinylidene fluoride (PVDF) composite ultrafiltration membranes were prepared by a phase inversion method, N,N-dimethylacetamide (DMAc) was used as solvent and polyvinylpyrrolidone (PVP) was used as dispersant, nanoTiO2 and AgNO3 were used as addictive materials. With different doping content of nanoTiO2 and silver ions, those hybrid films have different functions and structure. The basic performance and photocatalytic properties of those ultrafiltration membranes were studied in detail. The experiment results show that adding nanosized TiO2 particles will make the porosity of PVDF membrane increase, adding silver ion with low content can not improve water flux and porosity of membranes, however, nanoTiO2 and silver ions doping together can effectively improve the photocatalytic degradation rate.

scholarly journals Hydrophilic modification of poly(vinylidene fluoride) ultrafiltration membranes by surface UV photo-grafting with N,N′-methylene-bisacrylamide as monomer and Ce(IV) as initiator

2015 ◽  
Vol 6 (2) ◽  
pp. 280-289
Author(s):  
Baoli Shi ◽  
Zheng Li ◽  
Xing Su
Keyword(s):  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Ultrafiltration Membranes ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Hydrophilic Modification ◽  
Poly Vinylidene Fluoride ◽  
Modified Membrane ◽  
Porosity Measurements ◽  
Pure Pvdf

A UV photo-grafting method was utilised to enhance the hydrophilicity and anti-fouling property of self-made poly(vinylidene fluoride) (PVDF) ultrafiltration membranes. N,N′-methylene-bisacrylamide (MBAA) was used as monomer and Ce(IV) was used as initiator to obtain balance between grafting treatment consumption and enhanced performance. MBAA could be grafted onto the surface of pure PVDF membranes through a water-phase grafting method under UV photoradiation. When the MBAA concentration was 0.07 mol/L, the Ce(IV) concentration was 0.04 mol/L, and the irradiation duration was 3 min, the membrane surface was grafted with a sufficient amount of monomer under a UV photoradiation intensity of 5.0 mW/cm2. The water contact angle on the surface of the modified membrane decreased by approximately 16°, and flux recovery increased by approximately 40% compared with the pure PVDF membrane when treating river water. For bovine serum albumin rejection and porosity measurements no significant changes were observed between pure PVDF and graft-treated membranes. The enhanced performance of the modified membrane in this work was moderate, but the UV irradiation duration (3 min) was short. The integrative effects of UV modification in this work were satisfactory when both irradiation duration and enhanced performance were considered.

scholarly journals Characteristics and Preparation of PVDF Catalytic Membrane Modified by Nano-TiO2/Fe3+

2013 ◽  
Vol 7 (1) ◽  
pp. 39-43
Author(s):  
Xi Lijun ◽  
Zhang Li ◽  
Li Li ◽  
Chi Jingyuan ◽  
Lu Junchi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Polyvinylidene Fluoride ◽  
Sol Gel ◽  
Water Flux ◽  
Catalytic Membrane ◽  
X Ray Diffraction ◽  
Pvdf Membrane ◽  
Tio2 Sol ◽  
Ft Ir ◽  
Good Filtration

The polyvinylidene fluoride (PVDF)/Fe3+-TiO2 catalytic membrane was prepared by sol-gel method. It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR spectrum (FT-IR), mechanics capability, water flux, pepsin retention, porosity and contact angle etc. The catalytic activity of PVDF/Fe3+-TiO2 catalytic membrane was evaluated by the degradation of refractory dye Orange IV in the presence of H2O2. The results show that the addition of appropriate nano-sized TiO2 sol in the preparation of PVDF membrane has greatly improved some properties of the membrane such as microstructure, hydrophilic ability, mechanics intensity and water flux etc. The addition of Fe3+ ion in the preparation of PVDF membrane has greatly improved its catalytic activity to decompose H2O2. The catalytic activity of PVDF/Fe3+ -TiO2 is increased with the increase of the content of Fe3+ ion. When the content of Fe3+ _TiO2 sol is 21%, the content of Fe3+ ion is from 0.02% to 0.12%, the discolorization rate of Orange IV in this Fenton-like oxidation is from 61.2% to 90.5%. The catalytic activity of PVDF/Fe3+-TiO2 is not changed with the increase of the content of nano-sized TiO2. This kind of PVDF/Fe3+ -TiO2 catalytic membrane has not only good filtration efficiency but also good catalytic activity to effectively decompose H2O2.

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