The dependence of monovalent-ion selectivity of surface-sulfonated anion exchange membranes (s-AEMs) on the electrodialysis (ED) desalination current density, the concentration of equimolar ternary ...electrolyte (XCl + X2SO4) in the total concentration range 0.04–0.2 M, and the type of cations (X = H, Cs, Na) has been studied. The membrane current-voltage characteristics and values of the diffusion permeability coefficients in electrolyte solutions and their mixtures were measured. It was shown that Cl/SO4-selectivity coefficients (PCl|SO4) increase along with current density, reaching maximum values at the limiting current density (Ilim). The PCl|SO4 maximum value of 5.5 was achieved for the s-AEM-18 membrane in the ED-desalination of equimolar ternary electrolytes NaCl/Na2SO4, and CsCl/Cs2SO4 (total salt concentration 0.04 M) at 1.4 and 2.4 mA cm−2 current densities, respectively. At the overlimiting currents, the splitting of water and the decrease of Cl/SO4-selectivity were observed. The obtained experimental results are interpreted using simplified mass transfer and numerical simulations in the framework of Nernst-Planck-Poisson equations implemented in the COMSOL® Multiphysics software. The model represents the modified membrane as an asymmetric bipolar membrane with two diffusion boundary layers (DBL) in electrolyte solutions on both sides of the membrane interface. The model includes the water splitting at the bipolar boundary and the chemical equilibrium between sulfate and hydrogen sulfate ions. The numerical simulations qualitatively predict the behaviour of s-AEMs membranes when the abovementioned conditions change.
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•Monovalent ion selectivity of surface-sulfonated anion-exchange membranes was studied.•Selectivity of modified membranes reaches a maximum at limiting current density.•The selectivity decreases at the overlimiting currents and in acids solution.•The transport model with the SO42−/HSO4− equilibrium explains the decrease in selectivity.
Ion exchange membranes are widely used in chemical power sources, including fuel cells, redox batteries, reverse electrodialysis devices and lithium-ion batteries. The general requirements for them ...are high ionic conductivity and selectivity of transport processes. Heterogeneous membranes are much cheaper but less selective due to the secondary porosity with large pore size. The composition of grafted membranes is almost identical to heterogeneous ones. But they are more selective due to the lack of secondary porosity. The conductivity of ion exchange membranes can be improved by their modification via nanoparticle incorporation. Hybrid membranes exhibit suppressed transport of co-ions and fuel gases. Highly selective composite membranes can be synthesized by incorporating nanoparticles with modified surface. Furthermore, the increase in the conductivity of hybrid membranes at low humidity is a significant advantage for fuel cell application. Proton-conducting membranes in the lithium form intercalated with aprotic solvents can be used in lithium-ion batteries and make them more safe. In this review, we summarize recent progress in the synthesis, and modification and transport properties of ion exchange membranes, their transport properties, methods of preparation and modification. Their application in fuel cells, reverse electrodialysis devices and lithium-ion batteries is also reviewed.
It was shown experimentally that changing the indenter load P and the indentation size does not change the total deformation during indentation (εt≈const.), and that fracture does not influence the ...scale effect. For this reason the physical nature of the scale effect is revealed better by nanoindentation and under more “clean” conditions than in uniaxial deformation tests. The indentation size effect (ISE) is revealed as the change of mechanical properties determined by indentation. It was shown that reduction of the indent size leads to both increasing hardness and decreasing plasticity, determined by indentation. The phenomenological approach to the ISE (in which the power dependence of the indenter load P on the indenter displacement of h is used) made it possible to describe the dependence of nanohardness H(P) and H(h) by simple equations. Nanohardness was determined for 21 different crystals, and parameters that enabled the size dependence of H for these crystals to be calculated were determined. It is proposed to determine nanohardness at h=const. instead of P=const. and to recalculate H using our equations for fixed values of hf=1000nm for metals and hf=100nm for hard materials. The use of the developed technique makes it possible to compare results of nanohardness tests from different sources for different indenter loads.
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•Novel composite with selective perfluorosulfonic acid (PFSA) layer was developed.•Composite membrane was used for ethane/ethylene separation.•Selectivity up to 514 was achieved for ...Ag-form of PFSA layer and humidified gases.•Composite membranes have high ethylene permeability.•Membrane selectivity is determined by the thickness of the selective layer.
The PFSA-PP composite membrane was fabricated by deposition of a selective Nafion®-type poly(perfluorosulfonic acid) (PFSA) layer on a highly porous polypropylene (PP) film. The possibility of ethylene/ethane mixtures separation with the use of hydrogen and silver forms of the membrane was studied. A considerable influence of the gas mixture humidity on the ethylene permeability and selectivity of the membranes was demonstrated. The ethylene/ethane mixture separation factor reached 514, which is close to the values attained for Nafion® membranes, but with higher ethylene gas permeance of 28 GPU. The decrease in the selective layers thickness from 11 to 1 μm increases the ethylene permeance to 94.5 GPU with simultaneous decrease in the selectivity. As the ethylene content in the mixture decreases, the separation factors increase markedly.
Cation-exchange membranes based on polystyrene block copolymer with phenylsulfonylimide ionogenic groups in the Na+-form show conductivities up to 0.2 mS cm−1 in organic amides such as ...N-methylpyrrolidone and N,N-dimemylacetamide. These values are 2–2.5 orders of magnitude higher compared to those of conventional sulfonated cation-exchange membranes. A strong dependence of solvation degree and ionic conductivity on dielectric permittivity, chemical structure, and composition of the solvent, as well as on the nature of the membrane functional group, was noted and discussed. Further, based on the dependence of membrane’s solvation on the dimethylacetamide or acetonitrile content in the water/organic solvent mixtures and thermodynamic properties of these solvent mixtures, the reasons for the difference in ionic conductivity with a variation in the composition of the solvent and the functional groups of membranes are described. It was shown that conductivity of the cation-exchange membranes can increase dramatically even at low water concentration in the acetonitrile solution. It was demonstrated that the membranes with phenylsulfonylimide groups have high ionic conductivity in water/dimethylacetamide mixtures of any concentrations, which opens new prospects for their applications in electrochemical desalination and metal-ion batteries.
Radiation-induced grafted ion exchange membranes based on functionalized polystyrene were tested for the first time in reverse electrodialysis (RED). Сation and anion exchange membranes based on ...sulfonated and quaternized/chloromethylated poly(styrene-co-divinylbenzene) grafted on UV-oxidized polymethylpentene films with different conductivity and selectivity relationships were compared with each other and with different commercial ion-exchange membranes (IEMs), FujiFim® Type 1 and Type 2 and RALEX®. The synthesized grafted membranes provided the highest power density of lab-scale stacks with a total active membrane area of 72 cm2 with the use of 0.1 М/1 М NaCl (0.67 W m−2) and 0.1 М/5 М NaCl (2.1 W m−2) solutions. The use of grafted membranes with a low resistance ~0.5 Ω cm2 (0.5 М NaCl, 25 °C) did not benefit the stack resistance; the low selectivity of such membranes resulted in a lower voltage and a high non-selective diffusion current of the RED stack. Higher power densities and current efficiencies in some model systems are observed for stacks with grafted membranes with lower conductivity and higher selectivity.
•Radiation-induced grafted membranes were firstly tested in reverse electrodialysis (RED).•RED stacks with grafted membranes were compared with FujiFim® T1, T2 and RALEX® membranes.•Stacks with grafted membrane show the highest performance.•Maximal net power densities are 0.67 and 2.1 W m−2 with 0.1/1М NaCl and 0.1/5М NaCl.
This paper addresses hybrid ion exchange membranes fabricated by the synthesis of amorphous zirconium phosphate (dopant contents from 0.5 to 24 wt%) directly in the pore and channel system of ...heterogeneous cation-exchange membrane RALEX® CM (by in situ technique). The incorporation of zirconium phosphate nanoparticles into the membrane system of pores and channels leads to the displacement of the pore water. As a result, the cation transport numbers increase. The hybrid materials thus obtained are characterized by increased ionic resistance and enhanced monovalent ion selectivity. The former effect was eliminated by fabrication of a surface-modified membrane. The relative simplicity of modification, together with the benefits of the hybrid materials make them promising for some membrane processes. Using 31P MAS NMR and elemental analysis, considerable difference between the zirconium phosphate composition inside and outside the membrane was found.
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•Industrial cation-exchange membrane was in situ modified by zirconium phosphate.•The bulk- and surface-modified material was synthesized.•Hybrid materials have selectivity to monovalent cation transport.•Zirconium phosphate incorporation increase membrane permselectivity.•Surface-modified hybrid membranes have good conductivity also.
Increasing evidence suggests that both coding and non-coding regions of sarcomeric protein genes can contribute to hypertrophic cardiomyopathy (HCM). Here, we introduce an experimental workflow ...(tested on four patients) for complete sequencing of the most common HCM genes (
,
,
,
and
) via long-range PCR, Oxford Nanopore Technology (ONT) sequencing, and bioinformatic analysis. We applied Illumina and Sanger sequencing to validate the results, FastQC, Qualimap, and MultiQC for quality evaluations, MiniMap2 to align data, Clair3 to call and phase variants, and Annovar's tools and CADD to assess pathogenicity of variants. We could not amplify the region encompassing exons 6-12 of
. A higher sequencing error rate was observed with ONT (6.86-6.92%) than with Illumina technology (1.14-1.35%), mostly for small indels. Pathogenic variant p.Gln1233Ter and benign polymorphism p.Arg326Gln in
in a heterozygous state were found in one patient. We demonstrated the ability of ONT to phase single-nucleotide variants, enabling direct haplotype determination for genes
and
. These findings highlight the importance of long-range PCR efficiency, as well as lower accuracy of variant calling by ONT than by Illumina technology; these differences should be clarified prior to clinical application of the ONT method.
In the present paper, the influence of acid–base properties of inorganic particles in ion-exchange membrane-based nanocomposites on their physicochemical and transport properties was investigated. ...For this purpose, particles of Zr, Ti, and Si oxides have been synthesized in situ in the system of pores and channels of the membranes. Depending on the acid–base properties of oxides, introduction of nanoparticles can increase or decrease the water uptake, conductivity, and selectivity. A new approach to cross-linking of ion-exchange membranes by incorporating ZrO
2
particles into their matrix is proposed. Such cross-linking provides an improvement of swelling, conductivity, and salt permselectivity of the membrane in Na
+
-form. These parameters are important for successful application of such materials in direct and reverse electrodialysis, electrodeionization, and diffusion dialysis. For example, incorporation of 10 wt% of zirconia leads to a “cross-linking” of the membrane, i.e., binding of 45–50% of sulfonic groups, accompanied by a decrease of the water uptake by more than twofold and an increase of apparent transport numbers.
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