Effect of acidic aqueous solution on chemical and physical properties of polyamide NF membranes

Jun, Byung-Moon; Kim, Su Hwan; Kwak, Sang Kyu; Kwon, Young‐Nam

doi:10.1016/j.apsusc.2018.03.078

Cited by 74 publications

(25 citation statements)

References 57 publications

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“…As shown in Fig. 1a, the selective layer was created by interfacial polymerization of trimesoyl chloride (TMC) and m-phenylenediamine (MPD) since the fully aromatic polyamide possesses high stability in acidic condition 19 . The thickness and the morphology were controlled by changing the weight (g)/volume (mL) ratio of TMC from 0.02 to 0.8 wt/v % at a constant MPD concentration of 2 wt/v %.…”

Section: Resultsmentioning

confidence: 99%

Thin-film composite membrane breaking the trade-off between conductivity and selectivity for a flow battery

et al. 2020

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A membrane with both high ion conductivity and selectivity is critical to high power density and low-cost flow batteries, which are of great importance for the wide application of renewable energies. The trade-off between ion selectivity and conductivity is a bottleneck of ion conductive membranes. In this paper, a thin-film composite membrane with ultrathin polyamide selective layer is found to break the trade-off between ion selectivity and conductivity, and dramatically improve the power density of a flow battery. As a result, a vanadium flow battery with a thin-film composite membrane achieves energy efficiency higher than 80% at a current density of 260 mA cm −2 , which is the highest ever reported to the best of our knowledge. Combining experiments and theoretical calculation, we propose that the high performance is attributed to the proton transfer via Grotthuss mechanism and Vehicle mechanism in sub-1 nm pores of the ultrathin polyamide selective layer.

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Section: Resultsmentioning

confidence: 99%

Thin-film composite membrane breaking the trade-off between conductivity and selectivity for a flow battery

et al. 2020

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“…As previously mentioned, the alkali-catalyzed hydrolysis of an amide bond results in the formation of a carboxylic acid group and an amine bond [24], possibly leading to an increase in the absolute value of the surface charge. The authors of a previous study reported that the absolute value of the surface charge was increased after acid-catalyzed hydrolysis of a semi-aromatic NF membrane with almost the same isoelectric point as that of the membrane used in the present study [18]. In the present study, we measured the surface charge of the pristine and post-treated NF 90 membranes and found that the absolute value of the surface charge at pH 5.6 tended to increase with increasing post-treatment time ( Table 2).…”

Section: Intrinsic Properties Of the Nf 90 Membranesupporting

confidence: 59%

“…Generally, NF membranes comprise two different layers-a support layer and an active layer-to optimize water flux and salt rejection [17]. The active layers of NF membranes have been fabricated through interfacial polymerization using reactions between an amine-based monomer in an aqueous phase and an acyl chloride-based monomer in an organic solvent phase [18]. The reaction between m-phenylenediamine (MPD) and trimesoyl chloride (TMC), in particular, is a well-known method for fabricating polyamide (PA) active layers with high water flux and salt rejection [19].…”

Section: Introductionmentioning

confidence: 99%

“…The hydrolysis of polyamide bonds by acid or base has been explored in biological research because the skin of organisms contains polypeptides, which are chains of amino acids [23]. Amide bonds exhibit high chemical stability because of their resonance structure resulting from electronegative oxygen and lone-pair electrons of nitrogen [18]. However, the stable structure of amide bonds can be easily destroyed by acid or base under extreme pH conditions [24].…”

Section: Introductionmentioning

confidence: 99%

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Post-Treatment of Nanofiltration Polyamide Membrane through Alkali-Catalyzed Hydrolysis to Treat Dyes in Model Wastewater

Jun

Yoon

Park

2019

Water

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This research focused on the influence of post-treatment using alkali-catalyzed hydrolysis with a full-aromatic nanofiltration (NF) polyamide membrane and its application to the efficient removal of selected dyes. The post-treated membranes were characterized through Fourier transform infrared spectroscopy, goniometry, and zeta-potential analysis to analyze the treatment-induced changes in the intrinsic properties of the membrane. Furthermore, the changes in permeability induced by the post-treatment were evaluated via the measurement of water flux, NaCl rejection, and molecular weight cutoff (MWCO) under different pH conditions and post-treatment times. Major changes induced by the post-treatment in terms of physicochemical properties were the enhancement of permeability, hydrophilicity, and negative charge due to the hydrolysis of the membrane’s amide bonds. Four different dyes were selected as representative organic pollutants considering the MWCO of the post-treated membranes. Compared with the pristine NF membrane, membranes post-treated at pH 13.5 showed better water flux with similar rejection of the target dyes. On the basis of these results, the proposed post-treatment method for NF membranes can be applied to the removal of organic pollutants of various size.

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“…Analyses of PXRD peaks were carried out using well-known references (Jade software; Materials Data, Inc., Livermore, CA, USA). Chemical properties of biochar, AB, Fe 3 O 4 , and AB-Fe 3 O 4 were analyzed via Fourier-transform infrared spectroscopy (FTIR; Thermo Nicolet; Madison, WI, USA) in order to identify each chemical bond [33]. The surface morphology of AB, Fe 3 O 4 , and AB-Fe 3 O 4 was analyzed using scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM-EDX, S-4200; Hitachi, Tokyo, Japan).…”

Section: Characterization Methodsmentioning

confidence: 99%

Preparation of Activated Biochar-Supported Magnetite Composite for Adsorption of Polychlorinated Phenols from Aqueous Solutions

Jun

Kim

Han

et al. 2019

Water

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For this study, we applied activated biochar (AB) and its composition with magnetite (AB-Fe3O4) as adsorbents for the removal of polychlorophenols in model wastewater. We comprehensively characterized these adsorbents and performed adsorption tests under several experimental parameters. Using FTIR, we confirmed successful synthesis of AB-Fe3O4 composite through cetrimonium bromide surfactant. We conducted adsorption tests using AB and AB-Fe3O4 to treat model wastewater containing polychlorophenols, such as 2,3,4,6-Tetrachlorophenol (TeCP), 2,4,6-Trichlorophenol (TCP), and 2,4-Dichlorophenol (DCP). Results of the isotherm and the kinetic experiments were well adapted to Freundlich’s isotherm model and the pseudo-second-order kinetic model, respectively. Main adsorption mechanisms in this study were attributed to non-covalent, π-electron acceptor–donor interactions and hydrophobic interactions judging from the number of chloride elements in each chlorophenol and its hydrophobic characteristics. We also considered the electrostatic repulsion effect between TeCP and AB, because adsorption performance of TeCP at basic condition was slightly worse than at weak acidic condition. Lastly, AB-Fe3O4 showed high adsorption selectivity of TeCP compared to other persistent organic pollutants (i.e., bisphenol A and sulfamethoxazole) due to hydrophobic interactions. We concluded that AB-Fe3O4 may be used as novel adsorbent for wastewater treatment including toxic and hydrophobic organic pollutants (e.g., TeCP).

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Effect of acidic aqueous solution on chemical and physical properties of polyamide NF membranes

Cited by 74 publications

References 57 publications

Thin-film composite membrane breaking the trade-off between conductivity and selectivity for a flow battery

Thin-film composite membrane breaking the trade-off between conductivity and selectivity for a flow battery

Post-Treatment of Nanofiltration Polyamide Membrane through Alkali-Catalyzed Hydrolysis to Treat Dyes in Model Wastewater

Preparation of Activated Biochar-Supported Magnetite Composite for Adsorption of Polychlorinated Phenols from Aqueous Solutions

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