scholarly journals A Stable Anti-Fouling Coating on PVDF Membrane Constructed of Polyphenol Tannic Acid, Polyethyleneimine and Metal Ion

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1975 ◽  
Author(s):  
Lili Wu ◽  
Qiuhu Lin ◽  
Cong Liu ◽  
Wanyu Chen
Keyword(s):  
Contact Angle ◽  
Metal Ions ◽  
Tannic Acid ◽  
Metal Ion ◽  
Polyvinylidene Fluoride ◽  
Coating Layer ◽  
Retention Rate ◽  
Pure Water ◽  
Composite Membranes ◽  
Modified Membrane

A hydrophilic and anti-fouling coating layer was constructed on a polyvinylidene fluoride (PVDF) microfiltration membrane by a novel surface modification method. The pristine membrane was firstly coated by (3-chloropropyl) trimethoxysilane/polyethyleneimine and tannic acid. Then, the metal ion was induced on the coating layer to coordinate with tannic acid and polyethyleneimine, forming a more stable and hydrophilic coating on the surface. The membrane’s surface morphology and chemical element analysis showed that the Tannic acid/ polyethyleneimine (TA/PEI) coating layer was denser and had more stability after the addition of metal ions, and this may be due to the coordination bond formed between the TA/PEI coating and metal ions. The results of the water contact angle and pure water flux measurements showed that the hydrophilicity and wettability of the modified membranes were improved obviously after introducing the metal ion layers. The anti-fouling performance and stability of the modified membrane were also characterized by the underwater oil contact angle (OCA), the separation efficiency, and the contact angle variation value for before and after the rinsing experiment. The modified membrane showed obvious stability and antifouling. Moreover, the retention rate of some composite membranes could reach 99.6%.

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.

scholarly journals Removal of Dye from a Leather Tanning Factory by Flat-Sheet Blend Ultrafiltration (UF) Membrane

Membranes ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 47 ◽  
Author(s):  
Maryam Y. Ghadhban ◽  
Hasan Shaker Majdi ◽  
Khalid T. Rashid ◽  
Qusay F. Alsalhy ◽  
D. Shanthana Lakshmi ◽  
...  
Keyword(s):  
Contact Angle ◽  
Pure Water ◽  
Composite Membranes ◽  
Membrane Properties ◽  
Inversion Method ◽  
Average Roughness ◽  
Structural Formation ◽  
Blend Membrane ◽  
Flat Sheet ◽  
Pes Membrane

In this work, a flat-sheet blend membrane was fabricated by a traditional phase inversion method, using the polymer blends poly phenyl sulfone (PPSU) and polyether sulfone (PES) for the ultrafiltration (UF) application. It was hypothesized that adding PES to the PPSU polymer blend would improve the properties of the PPSU membrane. The effect of the PES concentration on the blend membrane properties was investigated extensively. The characteristics of PPSU-PES blend membranes were investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM), contact angle measure, and contaminant (dye) elimination efficiency. This study showed that PES clearly affected the structural formation of the blended membranes. A considerable increase in the average roughness (about 93%) was observed with the addition of 4% PES, with a higher mean pore size accompanied by a rise in the pores’ density on the surface of the membrane. The addition of up to 4% PES had a significant influence on the hydrophilic character of the PPSU-PES membrane, by lowering the value of the contact angle (CA) (i.e., to 56.9°). The performance of the PPSU-PES composite membranes’ UF performance was systematically investigated, and the membrane pure water permeability (PWP) was enhanced by 25% with the addition of 4% PES. The best separation removal factor achieved in the current investigation for dye (Drupel Black NT) was 96.62% for a PPSU-PES (16:4 wt./wt.%) membrane with a 50% feed dye concentration.

Study of antifouling modified ultrafiltration membrane based on the secondary treated water of urban sewage

2012 ◽  
Vol 66 (10) ◽  
pp. 2074-2082 ◽  
Author(s):  
Xiao-rong Meng ◽  
Liang Zhao ◽  
Lei Wang ◽  
Xu-dong Wang ◽  
Dan-xi Huang ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Layer Structure ◽  
Pure Water ◽  
Water Flux ◽  
Inversion Method ◽  
Treated Water ◽  
Urban Sewage ◽  
Cake Layer ◽  
Modified Membrane ◽  
Section Structure

Mixtures of polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA) containing hydrophilic ultrafiltration membranes were prepared by adding PVA (5 to 30%) to PVDF by the phase inversion method. The hydrophilic contact angle (CA), equilibrium water content, pure water flux and bovine serum albumin retention were studied to assess the membrane performance. The anti-fouling performance of modified membrane to the secondary treated water was evaluated by flux decline, washing recovery rate and fouling resistance analysis. Scanning electron microscopy showed that the cross-section structure of the membranes had finger-like pores, which were well developed and uniformly distributed, and the sub-layer structure was looser and more porous with the increasing content of PVA. The CA gradually decreased. The steady flux was 800 L/m2 h from P15 to P30, and the BSA retention sharply declined. The ultrafiltration tests for secondary treated water indicated that the main fouling source of the modified membrane was the concentration polarization and cake layer resistance. After physical flushing, the flux recovery ratio of the membrane could reach 100% when the PVA content was 5–15%, which shows excellent anti-pollution performance and good prospects for use in processing wastewater from urban sewage.

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%.

Preparation and Characterization of BaBi2Nb2O9/PVDF Inorganic-Organic Composite Ultrafiltration Membranes

2013 ◽  
Vol 681 ◽  
pp. 309-313
Author(s):  
Dong Hua Zhang ◽  
Li Jing Pan ◽  
Da Zhi Sun
Keyword(s):  
Polyvinylidene Fluoride ◽  
Pure Water ◽  
Water Flux ◽  
Composite Membranes ◽  
Rejection Rate ◽  
Inversion Method ◽  
Ultrafiltration Membranes ◽  
Cross Sectional ◽  
Uf Membranes ◽  
Phase Inversion Method

BaBi2Nb2O9/PVDF (polyvinylidene fluoride) composite ultrafiltration (UF)membranes were prepared by alloying BaBi2Nb2O9 (BBN) particles uniformly in the PVDF solution (15% polymer weight) and used a phase-inversion method. This paper studied the effect of the concentration of BBN from 0% to 5% in 0.2Mpa on pure water flux and rejection rate to Bovine serum albumin (BSA). The cross-sectional structures of composite membranes were observed by scanning electron microscopy (SEM). Moreover, XRD results revealed the crystal structure of PVDF. The experimental results showed that the BBN/PVDF composite ultrafiltration membranes were superior in separation performances than the pure PVDF membranes due to the addition of BBN.

scholarly journals Performance of Sprayed PVDF-Al2O3 Composite Coating for Industrial and Civil Applications

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6358
Author(s):  
Adel M. A. Mohamed ◽  
Hosam Hasan ◽  
Mohamed M. El-Sayed Seleman ◽  
Essam Ahmed ◽  
Sayed M. Saleh ◽  
...  
Keyword(s):  
Contact Angle ◽  
Polyvinylidene Fluoride ◽  
Coating Layer ◽  
Composite Coatings ◽  
Contact Angle Hysteresis ◽  
Nanoindentation Test ◽  
Al2o3 Nanoparticles ◽  
Glass Substrates ◽  
Coated Materials ◽  
Al2o3 Composite

Because of their great water repellency, Superhydrophobic coatings have a major impact on a variety of industrial applications. The current study’s key originality is the development of low-cost, stable, superhydrophobic, and corrosion-resistant composite coatings. In the present work, polyvinylidene fluoride (PVDF)/Al2O3 composite coatings were produced using the spray technique to investigate the wettability and corrosion behavior of the coated materials for industrial and civil applications. PVDF was mixed with various concentrations of Al2O3 nanoparticles, and the mixture was sprayed onto steel, aluminum, and glass substrates. The wettability and morphology of the coated surfaces were investigated using the sessile droplet method and scanning electron microscopy, respectively. The corrosion resistance of bare substrates was compared to that of those coated with PVDF alone and those coated with PVDF/Al2O3 nanoparticles using Tafel polarization techniques. The force of adhesion between the coat and the substrates was measured in pounds per square inch. A nanoindentation test was also used to measure the hardness of the coating layer. The PVDF/Al2O3 coated steel showed a significantly higher water contact angle and lower contact angle hysteresis, reaching 157 ± 2° and 7 ± 1°, respectively, compared to the coated aluminum and glass substrates. Corrosion test results showed that the superhydrophobic PVDF/Al2O3 coatings had a much higher corrosion protection efficiency for steel and aluminum than that of the PVDF ones. The PVDF/Al2O3 coated substrates showed moderate but still acceptable adhesion between the coating layer and the substrates. Moreover, the PVDF/Al2O3 coatings had much better mechanical properties than the PVDF only coatings. Such type of coating could be a promising candidate for possible industrial and civil applications.

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.

Preparation and Properties of Two-Dimensional Braid Heterogeneous-Reinforced Polyvinylidene Fluoride Hollow Fiber Membrane

2014 ◽  
Vol 936 ◽  
pp. 218-225 ◽  
Author(s):  
Quan Quan ◽  
Chang Fa Xiao ◽  
Hai Liang Liu ◽  
Wei Zhao ◽  
Xiao Yu Hu ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Polyvinylidene Fluoride ◽  
Polymer Solutions ◽  
Coating Layer ◽  
Pure Water ◽  
Water Flux ◽  
Two Dimensional ◽  
Hollow Fiber Membranes ◽  
Fiber Membranes ◽  
Pure Water Flux

The two-dimensional braid heterogeneous-reinforced (BHR) polyvinylidene fluoride (PVDF) hollow fiber membranes which include PVDF polymer solutions (coating layer) and the two-dimensional braid as a reinforcement were prepared through the dry-wet spinning process. The influence of PVDF concentration in polymer solutions on performance of BHR hollow fiber membranes were investigated by terms of pure water flux, protein rejection, a mechanical strength test, and morphology observations by a scanning electron microscope (SEM). The results of this study indicated that the tensile strength of the BHR PVDF hollow fiber membranes was nearly 75 MPa and the hollow fiber membranes were endowed with better flexibility performance. The BHR PVDF hollow fiber membranes had a favorable interfacial bonding between the coating layer and the two-dimensional braid. The pure water flux decreased, while the rejection ratio increased with the increase of polymer concentration.

Preparation and Characterization of Al2O3/TiO2/PVDF Polymer Composites Ultrafiltration Membrane

2012 ◽  
Vol 253-255 ◽  
pp. 865-870
Author(s):  
Sun Hong ◽  
Song Hua ◽  
Lu Yan
Keyword(s):  
Pore Size ◽  
Size Distribution ◽  
Composite Membrane ◽  
Polyvinylidene Fluoride ◽  
Retention Rate ◽  
Average Pore Size ◽  
Waste Water Treatment ◽  
Composite Membranes ◽  
Average Pore ◽  
Nanometer Particles

The polymer polyvinylidene fluoride (PVDF) membranes were modified by blending with nanometer particles to improve its hydrophilic property and anti-fouling performances in the process of waste water treatment. The organic macromolecule composite ultrafiltration (UF) membranes modified by the inorganic nanometer TiO2 and Al2O3 were prepared by a phase inversion process. The composite membranes performances, such as water flux, mechanical strength, water contact angle, retention rate, pores size and pores size distribution, were compared to those of organic membranes. The surface and sectional structures of membranes were observed by scanning electron microscope (SEM). The experimental results show that the composite membrane water fluxes increases 79.5% than that of organic membrane with 3% nanometer particles addition and the proportion of TiO2 and Al2O3 is 1:1. The composite membrane average pore size is larger than that of organic membrane and the pore size distribution is more uniform. The composite UF membrane has not only maintained PVDF membrane’s favorable performances but also improved its permeation performance, intensity, hydrophilic and anti-fouling performances.

Hydrophilically Modified Poly(vinylidene fluoride) Membrane for Removal of Methylene Blue Dye

2020 ◽  
Vol 17 (2) ◽  
pp. 1499-1502
Author(s):  
J. Hamdan ◽  
H. Hasbullah ◽  
M. N. M. Sokri ◽  
N. S. M. Sabri ◽  
M. A. F. Suran ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Contact Angle ◽  
Polyvinylidene Fluoride ◽  
Pure Water ◽  
Water Flux ◽  
Blue Dye ◽  
Separation Performance ◽  
Methylene Blue Dye ◽  
Pvdf Membrane ◽  
Pure Water Flux

Polyvinylidene Fluoride (PVDF) has been used as a membrane’s base material for wastewater treatment for quite some time. Due to PVDF hydrophobic nature, fouling will occur, thus, reducing the membrane performance. The main objective of this study was to investigate the effect of various chitosan loadings on membrane hydrophilicity and overall liquid separation performance. The loadings of chitosan (wt.%) used were neat PVDF, 0.25%, 0.5%, 0.75% and 1% in PVDF mixed matrix membrane. It was found that 0.75% chitosan membrane had the lowest contact angle of 63° making it the most hydrophilic. The pure water flux test on the membranes also showed the same trend where the lowest contact angle resulting in the highest pure water flux. The PVDF membrane containing 0.75% chitosan possessed the highest pure water flux of 43.5 Lm−2h−1. With the rejection of dye of over 43.12%. The study proved that adding chitosan into PVDF membrane certainly improved the membrane hydrophilicity and the percentage removal of methylene blue dye.

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