A novel type of polyelectrolyte complex/MWCNT hybrid nanofiltration membranes for water softening

Zhao, Faqiong; An, Quan‐Fu; Ji, Yan-Li; Gao, Congjie

doi:10.1016/j.memsci.2015.05.041

Cited by 98 publications

(20 citation statements)

References 60 publications

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“…due to its high biocompatibility, solubility in water, low toxicity, ability to form stable aqueous hydrogels, and film-forming properties. Sodium alginate is also actively applied in membrane technology as a polyelectrolyte [6][7][8] and for the preparation of membranes for fuel cell applications [9], vapor permeation [10][11][12], nanofiltration [13,14], ultrafiltration [15], and pervaporation [16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Novel Mixed Matrix Sodium Alginate–Fullerenol Membranes: Development, Characterization, and Study in Pervaporation Dehydration of Isopropanol

et al. 2020

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Novel mixed matrix dense and supported membranes based on biopolymer sodium alginate (SA) modified by fullerenol were developed. Two kinds of SA–fullerenol membranes were investigated: untreated and cross-linked by immersing the dry membranes in 1.25 wt % calcium chloride (CaCl2) in water for 10 min. The structural and physicochemical characteristics features of the SA–fullerenol composite were investigated by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic methods, scanning electron (SEM) and atomic force (AFM) microscopies, thermogravimetric analysis (TGA), and swelling experiments. Transport properties were evaluated in pervaporation dehydration of isopropanol in a wide concentration range. It was found that the developed supported cross-linked SA-5/PANCaCl2 membrane (modified by 5 wt % fullerenol) possessed the best transport properties (the highest permeation fluxes 0.64–2.9 kg/(m2 h) and separation factors 26–73,326) for the pervaporation separation of the water–isopropanol mixture in the wide concentration range (12–90 wt % water) at 22 °C and is suitable for the promising application in industry.

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Section: Introductionmentioning

confidence: 99%

Novel Mixed Matrix Sodium Alginate–Fullerenol Membranes: Development, Characterization, and Study in Pervaporation Dehydration of Isopropanol

et al. 2020

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“…This huge increase can be explained by the much higher interconnected ( Figure 2 ) porosity (70% vs. 40 %) of EPT-CNF nanopapers compared to PT-CNF nanopapers. Most importantly, by exhibiting this extremely high permeance already at pressures of 2 bar, EPT-CNF nanopapers outperform typical RO or NF membranes in terms of permeance [ 32 , 58 ].…”

Section: Resultsmentioning

confidence: 99%

“…Anim-Mensah et al [ 29 ] and Lai et al [ 30 ] used nanofiltration membranes, whereas Park et al demonstrated an electro-membrane process [ 3 ]. More recently, Rajabzadeh et al demonstrated layer-by-layer polyelectrolyte deposition on polyethersulfone hollow fiber ultrafiltration membranes [ 31 ], whereas Zhao et al introduced a polyelectrolyte complex/carbon nanotube nanofiltration membrane for this purpose [ 32 ] and Zhang applied a positively charged capillary membrane with carbon-nanotubes [ 33 ]. All these examples had appreciable performance with regards to rejection or removal of calcium and magnesium ions.…”

Section: Introductionmentioning

confidence: 99%

Rapid Water Softening with TEMPO-Oxidized/Phosphorylated Nanopapers

et al. 2019

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Water hardness not only constitutes a significant hazard for the functionality of water infrastructure but is also associated with health concerns. Commonly, water hardness is tackled with synthetic ion-exchange resins or membranes that have the drawbacks of requiring the awkward disposal of saturated materials and being based on fossil resources. In this work, we present a renewable nanopaper for the purpose of water softening prepared from phosphorylated TEMPO-oxidized cellulose nanofibrils (PT-CNF). Nanopapers were prepared from CNF suspensions in water (PT-CNF nanopapers) or low surface tension organic liquids (ethanol), named EPT-CNF nanopapers, respectively. Nanopaper preparation from ethanol resulted in a significantly increased porosity of the nanopapers enabling much higher permeances: more than 10,000× higher as compared to nanopapers from aqueous suspensions. The adsorption capacity for Ca2+ of nanopapers from aqueous suspensions was 17 mg g−1 and 5 mg g−1 for Mg2+; however, EPT-CNF nanopapers adsorbed more than 90 mg g−1 Ca2+ and almost 70 mg g−1 Mg2+. The higher adsorption capacity was a result of the increased accessibility of functional groups in the bulk of the nanopapers caused by the higher porosity of nanopapers prepared from ethanol. The combination of very high permeance and adsorption capacity constitutes a high overall performance of these nanopapers in water softening applications.

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“…Recently, a novel class of hybrid nanofiltration membranes were fabricated via in-situ ionic cross-linking between sodium alginate, polyethyleneimine, and MWNT–COOH [ 109 ]. It was shown that the permeability of these hybrid membranes towards water doubled from 13.4 to 27.0 L m −2 ·h −1 , when the mass ratio of MWNTs to sodium alginate was increased from 0.00 to 0.05.…”

Section: Filtration Applicationsmentioning

confidence: 99%

Carbon Nanotube Membranes: Synthesis, Properties, and Future Filtration Applications

2017

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Over the course of the past decade, there has been growing interest in the development of different types of membranes composed of carbon nanotubes (CNTs), including buckypapers and composite materials, for an ever-widening range of filtration applications. This article provides an overview of how different types of CNT membranes are prepared and the results obtained from investigations into their suitability for different applications. The latter involve the removal of small particles from air samples, the filtration of aqueous solutions containing organic compounds and/or bacteria, and the separation of individual liquids present in mixtures. A growing number of reports have demonstrated that the incorporation of CNTs into composite membranes confers an improved resistance to fouling caused by biomacromolecules and bacteria. These results are discussed, along with evidence that demonstrates it is possible to further reduce fouling by taking advantage of the inherent conductivity of composite membranes containing CNTs, as well as by using different types of electrochemical stimuli.

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A novel type of polyelectrolyte complex/MWCNT hybrid nanofiltration membranes for water softening

Cited by 98 publications

References 60 publications

Novel Mixed Matrix Sodium Alginate–Fullerenol Membranes: Development, Characterization, and Study in Pervaporation Dehydration of Isopropanol

Novel Mixed Matrix Sodium Alginate–Fullerenol Membranes: Development, Characterization, and Study in Pervaporation Dehydration of Isopropanol

Rapid Water Softening with TEMPO-Oxidized/Phosphorylated Nanopapers

Carbon Nanotube Membranes: Synthesis, Properties, and Future Filtration Applications

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