scholarly journals Characterization of PVDF/Graphene Nanocomposite Membranes for Water Desalination with Enhanced Antifungal Activity

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1279
Author(s):  
Emilia Gontarek-Castro ◽  
Maria Krystyna Rybarczyk ◽  
Roberto Castro-Muñoz ◽  
Monica Morales-Jiménez ◽  
Blanca Barragán-Huerta ◽  
...  

Seawater desalination is a worldwide concern for the sustainable production of drinking water. In this regard, membrane distillation (MD) has shown the potential for effective brine treatment. However, the lack of appropriate MD membranes limits its industrial expansion since they experience fouling and wetting issues. Therefore, hydrophobic membranes are promising candidates to successfully deal with such phenomena that are typical for commercially available membranes. Here, several graphene/polyvinylidene (PVDF_G) membranes with different graphene loading (0–10 wt%) were prepared through a phase inversion method. After full characterization of the resulting membranes, the surface revealed that the well-dispersed graphene in the polymer matrix (0.33 and 0.5 wt% graphene loading) led to excellent water repellence together with a rough structure, and a large effective surface area. Importantly, antifungal activity tests of films indicated an increase in the inhibition percentage for PVDF_G membranes against the Curvularia sp. fungal strain. However, the antifungal surface properties were found to be the synergistic result of graphene toxicity and surface topography.

2017 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Qtaishat ◽  
M. Khayet ◽  
T. Matsuura ◽  
K.C. Khulbe

This study aims at further improvement and development of the novel hydro–phobic/–philic composite membranes which are made specifically for membrane distillation (MD). This was attempted by studying the effect of the casting conditions during the membrane preparation process by the phase inversion method. Two variables were chosen to study, which are the evaporation time before gelation and the gelation path temperature. Some of the membranes were allowed to evaporate at room temperature for 2 or 3 minutes to study the effect of evaporation time. The temperature of the gelation path was varied to 4°C, 20°C or 60°C in order to study the gelation path temperature effect. The prepared membranes were characterized using gas permeation test, measurement of the liquid entry pressure of water (LEPw), X–ray photoelectron spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM). The effects of the casting conditions on the membrane morphology were identified, which enabled us to link the membrane morphology to the membrane performance. The membranes were then tested for desalination of 0.5 M NaCl solution by direct contact membrane distillation (DCMD) and the results were compared to commercial polytetraflouroethylene (PTFE) membrane. It was found that the membrane which was prepared with no evaporation time produced better flux than those with evaporation time. Regarding the gelation path temperature; the membrane prepared with gelation path temperature of 4°C was better than those prepared with gelation path temperature of 20 or 60°C. It should be emphasized that the DCMD flux of the membranes prepared with no evaporation time or with a gelation path temperature of 4°C was superior to the commercial one. Furthermore, all the prepared membranes were tested successfully for the desalination application. In other words, no NaCl was detected in the permeate.


2014 ◽  
Vol 925 ◽  
pp. 18-22 ◽  
Author(s):  
P.C. Oh ◽  
N.A. Mansur

In this paper, flat sheet polysulfone (PSF) membrane and polysulfone/montmorillonite (PSF/MMT) mixed matrix membranes with different MMT contents were prepared by dry-wet phase inversion method.N-methyl-2-pyrrolidone (NMP) and deionized water were used as a solvent and coagulant, respectively. The morphology and structure of membranes were analyzed by scanning electron microscope. Thermogravimetric analysis was also performed to examine the thermal decomposition of the synthesized membrane. Results showed that MMT had a good dispersion in the PSF matrix.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Youcef Sedkaoui ◽  
Naima Abdellaoui ◽  
Omar Arous ◽  
Hakim Lounici ◽  
Noreddine Nasrallah ◽  
...  

AbstractThe transport phenomena across polymeric membrane may be enhanced by applying various strengths inside or outside the system. Recently, polymer inclusion membrane (PIM) has been considered one of the most popular methods that acts as a sink for the contaminant and immobilizes it. In the literature, there is no report about how to achieve the synthesis of multi-layer PIMs. In this paper, an improvement of a novel category of membrane without carrier for performing ion separation is reported. Different membranes were elaborated from binary mixtures of polymers, cellulose triacetate (CTA), polymethyl methacrylate (PMMA) and polyvinyl chloride (PVC) using 2-nitrophenyl octyle-ether (NPOE) as plasticizer and carrier in the same time, in order to increase specific interactions between the different polymers. The membranes (Polymer 1– NPOE – Polymer 2) were synthesized by phase inversion method modified by changing the procedure of a plasticizer/carrier addition and characterized by FTIR, TGA, SEM, zeta potential and contact angle. The CTA-based membranes exhibited well-defined pores partially filled with the second polymer and NPOE. Overall, our results showed that the addition of NPOE resulted in homogeneous membranes with modified physical properties, such as thickness, and hydrophobicity. A study of transport of Pb(II) using the synthesized membranes was studied. Dialysis experiments of lead ions across a polymeric membrane have shown that (CTA + NPOE + PMMA) and (PMMA + NPOE + PVC) membranes proved a good performance in one stage by fixing 12.15 and 25.31% of lead, respectively, without any additionally added carrier and acids. These results confirm the affinity between a basic polymer (poly-methyl methacrylate) and the metallic ion (Pb2+).


Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 563
Author(s):  
Muhammad Zahid ◽  
Anum Rashid ◽  
Saba Akram ◽  
H. M. Fayzan Shakir ◽  
Zulfiqar Ahmad Rehan ◽  
...  

In this study, cellulose acetate (CA) was blended with sulfonated graphene oxide (SGO) nanomaterials to endow a nanocomposite membrane for wastewater treatment with improved hydrophilicity and anti-biofouling behavior. The phase inversion method was employed for membrane fabrication using tetrahydrofuran (THF) as the solvent. The characteristics of CA-SGO-doped membranes were investigated through thermal analysis, contact angle, SEM, FTIR, and anti-biofouling property. Results indicated that anti-biofouling property and hydrophilicity of CA-SGO nanocomposite membranes were enhanced with addition of hydrophilic SGO nanomaterials in comparison to pristine CA membrane. FTIR analysis confirmed the successful decoration of SGO groups on CA membrane surface while revealing its morphological properties through SEM analysis. Thermal analysis performed using DSC confirmed the increase in thermal stability of CA-SGO membranes with addition of SGO content than pure CA membrane.


2019 ◽  
Vol 69 (2) ◽  
pp. 122-133 ◽  
Author(s):  
Juan Xiong ◽  
Yexia Gong ◽  
Cong Ma ◽  
Xingtao Zuo ◽  
Jiajie He

Abstract The hydrophilic and antimicrobial polyvinylidene fluoride (PVDF) membrane was fabricated by phase inversion method. The prepared membranes with various concentrations of ZnO nanoparticles (NPs) were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and membrane properties were investigated in terms of hydrophilicity, water flux, BSA solution filtration experiments, etc. Antibacterial testing was also performed to examine the practicability of the PVDF-ZnO membranes in overcoming biofouling. The results of FTIR and XRD confirmed the presence of ZnO NPs in the polymer matrix. The membrane performance demonstrated the significance of hydrophilic nanoparticles towards the enhancement of membrane properties. The optimum amount of ZnO NPs was 1.5 wt% with a lower contact angle as well as highest flux and lowest filtration resistance. The presence of ZnO NPs in the membrane matrix exhibited a strong antibacterial activity increased with the increasing ZnO NPs' content. Incorporation of ZnO NPs into PVDF membranes may have great potential in developing high-performance antifouling membranes for separation process.


Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 437
Author(s):  
Minchul Ahn ◽  
Hyeongrak Cho ◽  
Yongjun Choi ◽  
Seockheon Lee ◽  
Sangho Lee

The optimization of the properties for MD membranes is challenging due to the trade-off between water productivity and wetting tendency. Herein, this study presents a novel methodology to examine the properties of MD membranes. Seven polyvinylidene fluoride (PVDF) membranes were synthesized under different conditions by the phase inversion method and characterized to measure flux, rejection, contact angle (CA), liquid entry pressure (LEP), and pore sizes. Then, water vapor permeability (Bw), salt leakage ratio (Lw), and fiber radius (Rf) were calculated for the in-depth analysis. Results showed that the water vapor permeability and salt leakage ratio of the prepared membranes ranged from 7.76 × 10−8 s/m to 20.19 × 10−8 s/m and from 0.0020 to 0.0151, respectively. The Rf calculated using the Purcell model was in the range from 0.598 μm to 1.690 μm. Since the Rf was relatively small, the prepared membranes can have high LEP (more than 1.13 bar) even at low CA (less than 90.8°). The trade-off relations between the water vapor permeability and the other properties could be confirmed from the results of the prepared membranes. Based on these results, the properties of an efficient MD membrane were suggested as a guideline for the membrane development.


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