| 1. |
- Ismail, Norafiqah, et al.
(författare)
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Investigating the potential of membranes formed by the vapor induced phase separation process
- 2020
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Ingår i: Journal of Membrane Science. - : Elsevier. - 0376-7388 .- 1873-3123. ; 597
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Forskningsöversikt (refereegranskat)abstract
- About 100 years ago, Zsigmondy and Bachmann invented a new method to induce phase inversion, the so-called vapor induced phase separation (VIPS). Since then many researchers have demonstrated this method in membrane fabrication. Here we present a review on membrane fabrication via VIPS to provide insights into membrane formation parameters in order to achieve desired properties for different applications. The key factors upon membrane preparation including solution parameters (i.e. polymer type and concentration, type of solvent, and additives) as well as operating parameters (i.e. exposure time, relative humidity, dissolution temperature, and vapor temperature) are comprehensively discussed. Furthermore, the design of a fouling-resistance membrane by the VIPS process has recently gained attention and is elaborated in details. The applications of the produced membranes via VIPS in water and wastewater treatment, gas separations, electrochemical applications (i.e. secondary batteries and supercapacitors) as well as in medical and biological applications are summarized and an outlook for future investigation is presented.
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| 2. |
- Kebria, Mohammad Reza Shirzad, et al.
(författare)
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Hyper-branched dendritic structure modified PVDF electrospun membranes for air gap membrane distillation
- 2020
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Ingår i: Desalination. - : ELSEVIER. - 0011-9164 .- 1873-4464. ; 479, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Dendrimers are a new class of polymeric materials owning unique properties such as hydrophobicity. In this study, hydrophobic hyper-branched dendritic (HB-Den) structures were synthesized via a polycondensation reaction between hydroxyl groups of boehmite and carboxylic groups of nitrilotriacetic acid (NTA) and was used to improve the hydrophobicity of electrospun nanofibrous membranes (ENMs). Effects of the different contents of HB-Den structures on membrane morphology, elemental properties, surface hydrophobicity, desalination performance and antifouling properties were assessed by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), water contact angle measurements and air gap membrane distillation (AGMD) experiments. Digital microscopy images showed monodisperse dendrimers with a tree-like structure. The water contact angle and liquid entry pressure (LEP) increased from around 129.3 degrees and 101 +/- 3.1 kPa for a neat PVDF membrane to 138.3 degrees and 121 +/- 2.2 kPa upon loading with 0.075 wt% HB-Den structures. FTIR analysis of the HB-Den containing ENMs confirmed the presence of carboxylic groups of NTA on the membrane surface. After desalination experiments, the 0.075 wt% HB-Den ENM showed a stable flux of 10.7 kg/m(2) h and 99.9% NaCl rejection over 15 h filtration of a 3.5 g/l NaCI solution. The anti-fouling properties of the ENMs were also enhanced by incorporation of the dendritic structures. The 0.075 wt% HB-Den ENM showed flux recovery of about 94% after 20 h desalination experiment using real seawater as a feed solution.
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| 3. |
- Mazani, Mahfar, et al.
(författare)
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Cu-BTC Metal−Organic Framework Modified Membranes for Landfill Leachate Treatment
- 2020
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Ingår i: Water. - : MDPI. - 2073-4441. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Mousavinejad, Atiyeh, et al.
(författare)
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Nickel-Based Metal–Organic Frameworks to Improve the CO2/CH4 Separation Capability of Thin-Film Pebax Membranes
- 2020
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 59:28, s. 12834-12844
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Tidskriftsartikel (refereegranskat)abstract
- Incorporating metal–organic frameworks (MOFs) into the thin layer of thin-film composite (TFC) membranes is an effective way of improving the CO2/CH4 separation performance. In this study, porous polyethersulfone (PES) membranes were surface-coated with a novel CO2-permeable layer consisting of CO2-philic Pebax and nickel-based MOF particles. The MOF particles were synthesized using nickel(II) acetate tetrahydrate as a metal source and 2-amino-1,4-dicarboxybenzene (NH2-BDC) as an organic linker. The properties and performance of the MOFs and synthesized membranes were assessed using analytical techniques including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), field-emission scanning electron microscopy (FE-SEM), and dynamic light scattering (DLS). DLS analysis showed that the MOF particle size range was in a range of 350–650 nm. Moreover, cross-sectional FE-SEM images depicted that a uniform and dense Pebax layer was shaped on top of the PES substrate. Well dispersion of the particles was demonstrated by surface FE-SEM imaging. DSC analysis showed that embedding Ni-NH2-BDC MOF particles into the Pebax-1657 film increased the crystallinity degree and the glass-transition temperature (Tg) of resulted membranes. To evaluate the membrane’s separation performance, permeation experiments were performed with CO2, CH4, and CO2/CH4 mixtures at ambient temperature. Embedding 5 wt % Ni-based MOF particles improved the CO2 permeability and CO2/CH4 selectivity from 19.05 Barrer and 32.2 to 31.55 Barrer and 94, respectively, compared to MOF-free membranes. Loading MOF particles into the Pebax matrix also improved the real gas separation factor. The obtained results demonstrate the great potential of the fabricated TFC membranes for gas separation.
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