scholarly journals Photocatalytic Nanofiltration Membrane Using Zr-MOF/GO Nanocomposite with High-Flux and Anti-Fouling Properties

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 711
Author(s):  
Rina Heu ◽  
Mohamed Ateia ◽  
Chihiro Yoshimura
Keyword(s):  
Composite Membrane ◽  
Self Assembly ◽  
Metal Organic Framework ◽  
Pure Water ◽  
Water Flux ◽  
Physical Stability ◽  
Chemical Characterization ◽  
High Flux ◽  
Assembly Method ◽  
Physical And Chemical

Photocatalytic nanofiltration (NF) membranes with enhanced flux and anti-fouling properties were prepared from a layered in situ nanocomposite of metal organic framework (i.e., UiO-66) and graphene oxide (UiO-66_GO) on a polyamide NF membrane using a pressure-assisted self-assembly method. For filtering pure water and humic acid, the composite membrane with a 10% UiO-66_GO loading (UiO-66_GO/NF-10%) showed a higher water flux (up to 63 kg/m2 h bar), flux recovery (80%), and total fouling resistance (33%) than the pristine NF membrane. Physical and chemical characterization revealed that this performance was attributed to improvements in hydrophilicity, porosity, surface smoothness, and charge repulsion. The UiO-66_GO/NF-10% composite membrane exhibited better physical stability with a relatively low mass loss (8.64%) after five washes than the membranes with mass loadings of 5 and 15 wt%. Furthermore, the UiO-66_GO/NF-10% composite membrane exhibited considerable photocatalytic activity under ultraviolet (UV) irradiation (bandgap: 3.45 eV), which reduced irreversible fouling from 20.7% to 2.4% and increased flux recovery to 98%. This study demonstrated that surface modification with the UiO-66_GO nanocomposite produced a high-flux anti-fouling photocatalytic NF membrane, which is promising for water purification.

Fabrication and Characterization of PVDF/UiO-66(Zr) Mixed Matrix Membrane on Non-Woven PET Support

2020 ◽  
Vol 1005 ◽  
pp. 108-115
Author(s):  
John Rhoel Cementina ◽  
Michael V. Torres ◽  
Dante P. Bernabe ◽  
Stephen Lirio ◽  
Micah Belle Marie Yap Ang ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Polyvinylidene Fluoride ◽  
Gas Permeability ◽  
Metal Organic Framework ◽  
Pure Water ◽  
Polymer Concentration ◽  
Water Flux ◽  
Mixed Matrix Membrane ◽  
Mixed Matrix ◽  
Metal Organic

Polyvinylidene fluoride (PVDF) membranes, enhanced with metal-organic framework (MOF), were fabricated on a non-woven polyethylene terephthalate (PET) support using the non-solvent induced phase inversion (NIPS) method to produce mixed matrix membrane (MMM). Polymer concentration of 10%, 15%, and 20% were used in the study whereas UiO-66(Zr) was used as a MOF filler. The resulting membranes were characterized in terms of their morphology, porosity, wettability, mechanical strength, pure water flux, and gas permeability. Results show that the presence of UiO-66(Zr) filler improved membrane morphology, mechanical strength, and hydrophobicity of MMM as compared to pristine PVDF.

scholarly journals In situ self-assembly of zirconium metal–organic frameworks onto ultrathin carbon nitride for enhanced visible light-driven conversion of CO2 to CO

2020 ◽  
Vol 8 (12) ◽  
pp. 6034-6040 ◽  
Author(s):  
Yanan Wang ◽  
Wenlong Zhen ◽  
Yiqing Zeng ◽  
Shipeng Wan ◽  
Haiwei Guo ◽  
...  
Keyword(s):  
Visible Light ◽  
Self Assembly ◽  
Carbon Nitride ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Assembly Method ◽  
Visible Light Driven ◽  
Metal Organic ◽  
Zirconium Metal

A series of Zr-porphyrin metal–organic framework (Zr-PMOF)/ultrathin g-C3N4 (UCN) heterostructure photocatalysts, as stable and efficient catalysts for the photoreduction of CO2, have been fabricated via a facile in situ hydrothermal self-assembly method.

Composite Membrane with a Calixarene-Containing Polyamide Functional Layer

2018 ◽  
Vol 71 (5) ◽  
pp. 360 ◽  
Author(s):  
Shun Ren ◽  
Dong-Qing Liu ◽  
Rui-Xiang Miao ◽  
Ze-Xian Zhu ◽  
Yu-Feng Zhang
Keyword(s):  
Composite Membrane ◽  
Photoelectron Spectroscopy ◽  
Interfacial Polymerization ◽  
Film Formation ◽  
Pure Water ◽  
Water Flux ◽  
Metal Cations ◽  
Heat Treating ◽  
Skin Layer ◽  
Functional Layer

Monolayer thin films were prepared at the interface of hexane and water to investigate the film formation ability of monomers through interfacial polymerization (IP). A tetra-calix[4]arene chloride derivative (CC) and a diamino-terminated PEG-1000 (DAP) produced a high strength membrane among the tested monomers. IP is consequently proposed to prepare a composite membrane with CC and DAP on a polysulfone (PSF) bulk membrane used for ultrafiltration. The top layer was cross-linked by heat-treating at 60°C for 2 min, with DAP (2 wt.-%) in water and CC (0.05 wt.-%) in hexane. Attenuated total reflectance (ATR)-FTIR and X-ray photoelectron spectroscopy data confirmed that a polyamide was formed on the surface of the PSF substrate. The skin layer was a 3 μm thick smooth thin-film as determined by field emission scanning electron microscopy (FE-SEM), and was also compact without gaps. Pure water flux was ~80.5 L m−2 h−1 under 0.5 MPa. Rejection of MgSO4 was round 22 %, since the calixarene-containing network was a sparse grid, and also had an affinity for metal cations. Although the skin of the composite membrane was compact under SEM, it was easy for metal cations to transfer through. This composite membrane might have good performance in other separation areas as a result of the special structure imparted by using the calixarenes as cross-linking knots.

scholarly journals Antifouling Polyethersulfone-Petrol Soot Nanoparticles Composite Ultrafiltration Membrane for Dye Removal in Wastewater

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 361
Author(s):  
Nkechi P. Nwafor ◽  
Richard M. Moutloali ◽  
Keneiloe Sikhwivhilu ◽  
Oluwole B. Familoni ◽  
Luqman A. Adams
Keyword(s):  
Composite Membrane ◽  
Membrane Filtration ◽  
Dye Removal ◽  
Pure Water ◽  
Water Flux ◽  
Composite Membranes ◽  
Water Remediation ◽  
Blue Dye ◽  
Phase Inversion Technique ◽  
Pure Water Flux

Engineered nanoparticles are known to boost membrane performance in membrane technology. Hitherto, tunable properties that lead to improved hydrophilicity due to increased surface oxygen functionalities upon oxidation of petrol soot have not been fully exploited in membrane filtration technology. Herein, the integration of oxidized petrol soot nanoparticles (PSN) into polyethersulfone ultrafiltration membranes produced via phase inversion technique for dye removal in wastewater is reported. The nanoparticles, as well as the composite membranes, were characterized with diverse physicochemical methods, particularly TEM, SEM, BET, AFM, contact angle, etc. The effect of varying the ratio of PSN (0.05–1.0 wt %) on the properties of the composite membrane was evaluated. The composite membranes displayed increased hydrophilicity, enhanced pure water flux, and antifouling properties relative to the pristine membrane. For example, the obtained pure water flux increased from 130 L·m−2·h−1 for base membrane to 265 L·m−2·h−1 for the best composite membrane (M4). The best flux recovery ratio (FRR) observed for the membranes containing PSN was ca. 80% in contrast to 49% obtained with the pristine membrane indicative of the positive influence of PSN on membrane antifouling behavior. Furthermore, the PSN composite membranes displayed relatively selective anionic dye rejection of ˃95% for Congo red and between 50–71% for methyl orange compared with 42–96% rejection obtained for cationic methylene blue dye with increasing PSN content. The successful fabrication of polyethersulfone–PSN composite membranes by a simple blending process opens a novel route for the preparation of economical, functional, and scalable water purification membranes capable of addressing the complex issue of water remediation of organic azo dyes.

scholarly journals Biochar/Kevlar Nanofiber Mixed Matrix Nanofiltration Membranes with Enhanced Dye/Salt Separation Performance

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 443
Author(s):  
Shiguo Gu ◽  
Lei Li ◽  
Fei Liu ◽  
Jian Li
Keyword(s):  
Structural Characteristics ◽  
Pure Water ◽  
Water Flux ◽  
Physical Stability ◽  
Mixed Matrix Membranes ◽  
Mixed Matrix Membrane ◽  
Inversion Method ◽  
Separation Performance ◽  
Mixed Matrix ◽  
High Separation

Mixed matrix membranes have received ever-growing attention due to their high separation performance, taking the advantages of both porous fillers and polymer backbones. However, limitations still exist due to the instability of polymers in harsh environments. Here, Kevlar aramid nanofibers, a nanoscale version of poly(paraphenylene terephthalamide), were applied to fabricate a nanofiltration membrane by a thermo-assisted phase inversion method due to their high mechanical strength, physical stability and resistance to solvents. Biochar was incorporated in the Kevlar nanofibers to evaluate its performance in dye/salt separation performance. The fillers’ distribution in the polymeric matrix, structural characteristics, and the interaction of fillers with the polymer in the membrane were characterized via SEM, FTIR, AFM and contact angle analysis. Under the optimal fabrication conditions, the obtained membrane exhibited a pure water flux of 3.83 L m−2 h−1 bar−1 with a dye rejection of 90.55%, 93.54% and 95.41% for Congo red, methyl blue and Reactive blue 19, respectively. Meanwhile, the mixed matrix membrane maintained a salt rejection of 59.92% and 85.37% for NaCl and Na2SO4, respectively. The obtained membrane with high separation performance suggested that Kevlar nanofiber and biochar are good candidates for membrane synthesis.

scholarly journals Cu-BTC Metal−Organic Framework Modified Membranes for Landfill Leachate Treatment

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 91 ◽  
Author(s):  
Mahfar Mazani ◽  
Sadegh Aghapour Aktij ◽  
Ahmad Rahimpour ◽  
Naser Tavajohi Hassan Kiadeh
Keyword(s):  
Landfill Leachate ◽  
Metal Organic Framework ◽  
Pure Water ◽  
Water Flux ◽  
Leachate Treatment ◽  
X Ray ◽  
Membrane Performance ◽  
Metal Organic ◽  
Pure Water Flux ◽  
Uf Membranes

In this study, Cu-BTC (copper(II) benzene-1,3,5-tricarboxylate) metal-organic frameworks (MOFs) were incorporated into the structure of polysulfone (PSf) ultrafiltration (UF) membranes to improve the membrane performance for landfill leachate treatment, whereby different concentrations of Cu-BTC (0.5, 1, 1.5, 2 wt%) were added to the PSf casting solution. The successful incorporation of Cu-BTC MOFs into the modified membranes was investigated by field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray (EDX). The Cu-BTC-modified PSf membranes showed higher performance in terms of flux and rejection, as compared to the neat PSf membrane. For example, the pure water flux (PWF) of neat membrane increased from 111 to 194 L/m2h (LMH) by loading 2 wt% Cu-BTC into the membrane structure, indicating 74% improvement in PWF. Furthermore, the flux of this membrane during filtration of landfill leachate increased up to 15 LMH, which indicated 50% improvement in permeability, as compared to the neat membrane. Finally, the modified membranes showed reasonable antifouling and anti-biofouling properties than the blank membrane.

scholarly journals Hot-Pressed Wet-Laid Polyethylene Terephthalate Nonwoven as Support for Separation Membranes

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1547 ◽  
Author(s):  
Lei Xia ◽  
Quping Zhang ◽  
Xupin Zhuang ◽  
Shuo Zhang ◽  
Chengpu Duan ◽  
...  
Keyword(s):  
Response Surface ◽  
Polyethylene Terephthalate ◽  
Composite Membrane ◽  
Hot Pressing ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Water Flux ◽  
Separation Membranes ◽  
Phase Inversion Technique ◽  
Small Pore

In this work, a polyethylene terephthalate (PET) nonwoven support was prepared by wet-laid and hot-press technology and used as support for separation membranes. The properties of the PET nonwoven support were studied to determine the effect of hot-pressing parameters and PET fiber ratio, and were optimized by response surface methodology. Result showed that the PET nonwoven support with 62% low melting point PET (LPET-180) fibers obtained satisfactory properties and structure after hot pressing at 220 °C under the pressure of 9 MPa for 20 s. The response surface analysis indicated that the temperature and time of hot pressing and the fiber ratio were the most important factors affecting the strength and air permeability of the PET nonwoven support. After hot pressing, the PET nonwoven support exhibited interconnected structure, small pore size, low porosity, and high strength. Then phase inversion technique was applied to prepare a polysulfone (PSF) layer on the PET nonwoven support and an ultra-thin polyamide (PA) active layer was prepared by interfacial polymerization on the PSF layer. The practicality of PET nonwoven support was verified by testing the pure water flux and retention of the PA composite membrane and the structural change of the PA composite membrane before and after use. The results proved the feasibility and remarkable application prospects of hot-pressed wet-laid PET nonwoven support as support for separation membranes.

scholarly journals The Construction of a Hydrophilic Inorganic Layer Enables Mechanochemically Robust Super Antifouling UHMWPE Composite Membrane Surfaces

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 569 ◽  
Author(s):  
Rong Liu ◽  
Shusen Liu ◽  
Junrong Yu ◽  
Wei Zhang ◽  
Jiamu Dai ◽  
...  
Keyword(s):  
Composite Membrane ◽  
Membrane Surface ◽  
Pure Water ◽  
Water Flux ◽  
Chemical Properties ◽  
Lower Surface ◽  
Inorganic Layer ◽  
Nanoparticle Layer ◽  
Membrane Surfaces ◽  
Uhmwpe Composite

In this study, a facile and effective method is adopted to prepare mechanochemically robust super antifouling membrane surfaces. During the process, vinyl trimethoxy silane (VTMS) was used as the reactive intermediate for coupling the hydrophilic inorganic SiO2 nanoparticle layer on to the organic ultra-high-molecular-weight polyethylene (UHMWPE) membrane surface, which created hierarchical nanostructures and lower surface energy simultaneously. The physical and chemical properties of the modified UHMWPE composite membrane surface were investigated. FTIR and XPS showed the successful chemical grafting of VTMS and SiO2 immobilization, and this modification could effectively enhance the membrane’s surface hydrophilicity and filtration property with obviously decreased surface contact angle, the pure water flux and bovine serum albumin (BSA) rejection were 805 L·m−2·h−1 and 93%, respectively. The construction of the hydrophilic nano-SiO2 layer on the composite membrane surface for the improvement of membrane antifouling performance was universal, water flux recovery ratio values of BSA, humic acid (HA), and sodium alginate (SA) were all up to 90%. The aim of this paper is to provide an effective approach for the enhancement of membrane antifouling performance by the construction of a hydrophilic inorganic layer on an organic membrane surface.

scholarly journals Preparation and Physicochemical Properties of Tannin-Immobilized Membrane Adsorbent

2021 ◽  
Vol 11 (20) ◽  
pp. 9684
Author(s):  
Wei Luo ◽  
Huiting Lin ◽  
Zhihao Wu ◽  
Jingteng Chen ◽  
Ruiyang Chi ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Pure Water ◽  
Water Flux ◽  
Flux Analysis ◽  
Hydroxyl Groups ◽  
High Flux ◽  
Microporous Membranes ◽  
Effective Removal ◽  
Surface Contact Angle

Plant tannins have the ability to form stable complexes with metal ions, while microporous membranes have low pressure drop and high flux characteristics. Combining these two materials, a new type of tannin-immobilized membrane (M-TAN) adsorption material has been developed. The PA-BWT, PVDF-BWT, CELL -BWT, and PA-AA-BWT were prepared using different types of microporous membranes as substrates, which maintained the porous structure of the membranes and had the characteristics of high flux and fast filtration rate. The surface contact angle and pure water flux analysis showed that the introduction of tannin with multi-phenolic hydroxyl groups increased the hydrophilicity and water flux of the M-TANs. The adsorption performance shows that the adsorption capacity of four kinds of M-TANs for UO22+ is in the order of PA-BWT > PA-AA-BWT > PVDF-BWT > CELL-BWT, and PA-BWT has the largest adsorption capacity of 0.398 mmol g−1. In addition, the adsorption isothermal and kinetic data of PA-BWT were well fitted by the Langmuir equation and the Elovich model, respectively. The negative values of ΔG for UO22+ adsorption on PA-BWT indicated that adsorption is a spontaneous and favorable process. These facts indicate that PA-BWT can be used as a low-cost adsorbent for effective removal of UO22+ from aqueous solutions.

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