scholarly journals Anticorrosion Performance of PVDF Membranes Modified by Blending PTFE Nanoemulsion and Prepared through Usual Non-Solvent-Induced Phase Inversion Method

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 420
Author(s):  
Tianshu Liu ◽  
Xiaoji Zhou ◽  
Yizhuo Sun ◽  
Renbi Bai

In this study, PVDF/PTFE composite membranes were prepared by adding a PTFE nanoemulsion to a PVDF solution and casting it through the conventional non-solvent-induced phase separation method. The objective was to explore the effectiveness of using a simple and economical method to modify PVDF membranes with PTFE to enhance their anticorrosion performance, especially under highly acidic or alkaline conditions. PTFE nanoparticles (of around 200 nm in size) in nanoemulsion form were blended with PVDF at a mass ratio of PTFE:PVDF in the range of 0–0.3:1. The obtained membranes were examined to determine the effect of the added PTFE nanoparticles on the structure of the modified PVDF membranes as well as on their mechanical strength and surface characteristics. The membranes were then immersed in various concentrations of acidic or alkaline solutions for varied durations ranging from a few days up to as long as 180 days (6 months). The impacts of by the corrosive solutions on the tensile strength, surface roughness, and water flux of the membranes with different exposure times were quantified. The results showed that although a certain extent of change may occur with extended immersion times, greatly enhanced anticorrosion performance was obtained with the prepared PVDF/PTFE membranes compared with the unmodified PVDF membrane. For example, after being immersed in 5 mol-H+··L−1 H2SO4, HCl, and HNO3 solutions for 6 months, the tensile strength at breaking point remained at up to 69.70, 74.07, and 71.38%, respectively, of the initial strength for the PVDF/PTFE (M30) membrane. This was in contrast to values of only 55.77, 70.43, and 61.78% for the unmodified PVDF membrane (M0). Although the water flux and surface roughness showed a change trends to the tensile strength, the PVDF/PTFE (M30) membrane had much higher stability than the PVDF (M0) membrane. In a continuous filtration experiment containing H2SO4 at 0.01 mol-H+·L−1 for 336 h (14 days), the PVDF/PTFE membrane showed a maximum flux change of less than 30%. This was in comparison with a change of up to 50% for the PVDF membrane. However, the PVDF/PTFE membranes did not seem to have a greatly enhanced anticorrosion performance in the alkaline solution environment tested.

2018 ◽  
Vol 197 ◽  
pp. 09007
Author(s):  
Syawaliah Syawaliah ◽  
Nasrul Arahman ◽  
Medyan Riza ◽  
Sri Mulyati

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.


2013 ◽  
Vol 746 ◽  
pp. 390-393
Author(s):  
Qiong Zhi Gao ◽  
Hong Qiang Li ◽  
Xing Rong Zeng

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.


2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Muhamad Zaini Yunos ◽  
Zawati Harun ◽  
Hatijah Basri ◽  
Mohd Fikri Shohur ◽  
Mohd Riduan Jamalludin ◽  
...  

The influence of zinc oxide and silver (I) oxide in polysulfone ultrafiltration membrane was studied. The membranes were prepared via phase inversion method. The morphology, surface roughness, hydrophillicity and antibacterial properties of membrane were investigated using SEM, AFM and contact angle device consecutively. It was found that membrane with zinc oxide additive has excellent pure water flux as compared to silver (I) oxide. However silver (I) oxide has better humic acid rejection due to the tradeoff effect. SEM-EDX for PSf/silver (I) oxide reveals that the accumulation of silver on top area in cross section of membrane while for zinc oxide seems more concentrated on the bottom. Interestingly, the AFM results support the previous result when PSf/zinc oxide showed better surface roughness on the top of the membrane. Eventhough zinc oxide is known one of antibacterial material, however from qualitative experiment using disc diffusion test (e-coli), there is no inhibition ring for PSf/zinc oxide membrane as compared to membrane with PSf/silver (I) oxide membrane which shows excellence inhibition ring.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 510
Author(s):  
Muhammad Zahid ◽  
Saba Akram ◽  
Anum Rashid ◽  
Zulfiqar Ahmad Rehan ◽  
Talha Javed ◽  
...  

A novel, functionalized graphene oxide–based cellulose acetate membrane was fabricated using the phase inversion method to improve the membrane characteristics and performance. We studied the effect of aminated graphene oxide (NH2–GO) composite on the CA membrane characteristics and performance in terms of membrane chemistry, hydrophilicity, thermal and mechanical stability, permeation flux, and antibacterial activity. The results of contact angle and water flux indicate the improved hydrophilic behavior of composite membranes in comparison to that of the pure CA membrane. The AGO-3 membrane showed the highest water flux of about 153 Lm−2h−1. The addition of hydrophilic AGO additive in CA membranes enhanced the antibacterial activity of AGO–CA membranes, and the thermal stability of the resulting membrane also improved since it increases the Tg value in comparison to that of a pristine CA membrane. The aminated graphene oxide (NH2–GO) was, therefore, found to be a promising additive for the fabrication of composite membranes with potent applications in wastewater treatment.


2013 ◽  
Vol 681 ◽  
pp. 309-313
Author(s):  
Dong Hua Zhang ◽  
Li Jing Pan ◽  
Da Zhi Sun

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.


2011 ◽  
Vol 311-313 ◽  
pp. 1818-1821 ◽  
Author(s):  
Yang He ◽  
Jun Ming Hong

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%.


2021 ◽  
Author(s):  
Hongbin Li ◽  
chao liu ◽  
Yongqiang Guo ◽  
Shuzhen Gao

Abstract Developing an antifouling and stable separation poly (vinylidene fluoride) (PVDF) membrane for water treatment is of great significance but challenging due to the limitations of its low surface properties and strong hydrophobicity. In this study, a novel multi-block composite ultrafiltration membrane was developed using the mosaic-assembled doping of pineapple leaf nanocrystalline cellulose and g-C3N4. The effects of adding different components on the PVDF composite membrane properties have been analyzed. The surface chemical composition, surface morphology, crystallinity and thermal stability of the composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Both of the tensile strength and elongation length of the PVDF composite membranes were enhanced due to the addition of pineapple leaf nanocellulose and g-C3N4, and the tensile strength and elongation length of PVDF/PEG/g-C3N4/Pineapple leaf nanocellulose composite membrane can reach 10.61 MPa and 8.85 mm. The porosity of the PVDF composite membranes was 46.6%, respectively. The water flux and flux recovery ratio of PVDF/PEG/g-C3N4/Pineapple leaf nanocellulose also can reach 256.75 L/(m2 ⋅h) and up to 82.1%. All the above experimental data showed that the addition of pineapple leaf nanocellulose and g-C3N4 can greatly improve the performance of the PVDF composite membrane. The prepared modified membrane has potential application value in the field of wastewater separation and treatment.


2011 ◽  
Vol 675-677 ◽  
pp. 391-394
Author(s):  
Shuai Li ◽  
Yuan Gao ◽  
Lu Bai ◽  
Wei Qian Tian ◽  
Li Ping Zhang

Nanocrystalline cellulose (NCC) was used to improve hydrophilic property and permeability of polysulfone (PS) membrane. It was prepared from cellulose pulp by acid-catalyzed hydrolysis and high-pressure homogenization. The casting solution of a PS/NCC blend was obtained by adding NCC to a PS membrane solution and the composite membrane was prepared by phase-inversion method. In addition, the concentration of NCC was increased gradually from 0 wt% to 1.1 wt% during the preparation in order to examine the pure water flux and the retention of a bovine serum albumin (BSA). Simultaneously, the porosity and mean pore size of the membrane was detected and calculated. The result showed that the capacity for ultrafiltration was enhanced with appropriate NCC content. The membranes were also observed with atomic force microscopy (AFM) and scanning electron microscopy (SEM) to explore their porous structures.


2016 ◽  
Vol 74 (2) ◽  
pp. 333-342 ◽  
Author(s):  
Ahmad Akbari ◽  
Vahid Reza Abbaspour ◽  
Seyed Majid Mojallali Rostami

The goal of the present work is the Tabas coal preparation plant wastewater treatment using membrane technology. Polyacrylonitrile membrane was prepared through phase inversion method and then developed by annealing process. Also, high fouling resistance membranes were prepared by the embedding of TiO2 nanoparticles using self-assembling and blending methods. The effect of immersion time and TiO2 nanoparticles concentration was investigated using two techniques. The chemical structure, morphology, hydrophilicity, molecular weight cut-off and antifouling properties of membranes were characterized using energy-dispersive X-ray spectroscopy, scanning electron microscopy, contact angle, polyethylene glycol tracers, and cationic polyacrylamide (C-PAM) filtration, respectively. The optimized self-assembled membrane was shown to have more than 31.2% higher water flux with the best antifouling properties. Improving hydrophilicity leads to excellent antifouling properties for composite membranes and illustrates a promising method for fabrication of high performance membrane for C-PAM separation.


2018 ◽  
Vol 24 (7) ◽  
pp. 50
Author(s):  
Mohammed Amer Abdul-Majeed

In this study, polymeric ultrafiltration (UF) membranes were prepared by phase inversion method to obtain both antibacterial and organic antifouling properties. The membranes were cast from a solution of polyvinylidene fluoride (PVDF) and formative silver (Ag) nanoparticles were successfully immobilized on a polymer. This was done using a solvent N, N-dimethylformamide (DMF) which is a solvent for the PVDF polymer meanwhile it is a reducing agent for silver ion. The effect of silver nanoparticles additives on the performance of polymeric ultrafiltration membrane was verified. Chemical composition and morphology of the surfaces of the membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The antibacterial property of modified membrane and the influence of silver nanoparticles on pure water flux of composite membrane at 0.2 Mpa were also verified. The experimental results obtained concluded that the composite membrane properties have been improved by the integration of Ag nanoparticles. The grafted membrane with silver nanoparticles has shown a clear ability to inhibit the growth of E. coli, Pseudomonas Aeruginosa, and Bacillus Cereus. While the clean PVDF membrane (without any additives) did not show any effect of preventing the growth of these species of bacteria referred to above. The pure water flux, porosity and the mean pore size of composite membrane can reach 261.8 L/m2 h, 85.4%, and 0.0206 µm, respectively, and it was much more than that of pure PVDF membrane.  


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