Preparation and ionic selectivity of carbon-coated alumina nanofiber membranes

Лебедев, Д. В.; Shiverskiy, A. V.; Симунин, М. М.; Солодовниченко, В. С.; Парфенов, В. А.; Bykanova, Victoria; Khartov, S. V.; Ryzhkov, Ilya I.

doi:10.1134/s096554411704003x

Cited by 11 publications

(8 citation statements)

References 45 publications

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“…Ion transport is carried out only through the membrane pores. The approach under consideration can also be applied to the description of nanofiber membranes with a conductive carbon coating [20,21]. In this case, the average radius calculated from the pore size distribution can be selected as the pore radius.…”

Section: Formulation Of the Problemmentioning

confidence: 99%

“…It should be noted that the disadvantage of modified track membranes is their low porosity (less than 1%), which complicates their use in baromembrane processes. Highly porous membranes (60-70%) based on alumina nanofibers with a diameter of about 10 nm coated with a carbon layer by chemical vapor deposition were proposed in [20,21]. The possibility of changing the membrane potential at zero current and ionic conductivity of the membrane by applying an external potential to its surface was shown in [22].…”

Section: Introductionmentioning

confidence: 99%

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Modelling of Conductive Nanoporous Membranes with Switchable Ionic Selectivity

Ryzhkov

Vyatkin

Mikhlina

2020

Membr. Membr. Technol.

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An interesting area of modern membrane science is the development of "smart" membranes, which can affect the transport properties of selected components via external tuning. When the target components are ions, such a tuning can be realized with the help of electric field created by the conductive pore surface. We have proposed in this work a mathematical model of ions transport in a cylindrical nanopore with the electronic charge at the conductive surface and the chemical charge, which is separated from the surface by the Stern layer. The model is based on one-dimensional equations for potential, ion concentrations, and pressure in the diffuse layer. It is applied for describing the membrane potential at zero current, which characterizes the type and strength of ionic selectivity. It is shown that the change of surface potential in the direction from negative to positive results in the continuous change of pore selectivity from cation to anion. The decrease in the Stern layer capacitance and increase in the pore radius lead to the decrease in ionic selectivity. The presence of positive (negative) chemical charge causes the shift of potential value, at which the selectivity is switched, in the direction of negative (positive) values. At this value of potential, the membrane becomes non-selective, the diffusive flux of ions reaches maximum, and the osmotic flow ceases. The suggested model provides a qualitative and quantitative description of experimental results on switchable selectivity of tracketched membranes modified by the gold coating.

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Section: Formulation Of the Problemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modelling of Conductive Nanoporous Membranes with Switchable Ionic Selectivity

Ryzhkov

Vyatkin

Mikhlina

2020

Membr. Membr. Technol.

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“…Raman spectroscopy and measurement of electrical resistance confirm this conclusion. These findings could be employed for further development of conductive nanoporous membranes for switchable ion transport [36,37,40] as well electroconductive ceramics [33,34].…”

Section: Resultsmentioning

confidence: 92%

“…Recently, we have proposed a novel type of ion-selective membranes based on carboncoated Nafen nanofibers, which combine the advantages of ceramic nanofibrous media with good electrical conductivity [36,37]. These composite membranes demonstrate high ionic selectivity and appear to be very promising for nano-and ultrafiltration, separation of charged species, and switchable ion-transport selectivity [38][39][40].…”

Section: Introductionmentioning

confidence: 99%

Coupled thermal analysis of carbon layers deposited on alumina nanofibres

et al. 2019

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Catalyst-free chemical vapor deposition is used to form thin (1-2 nm) carbon layers on the surface of alumina nanofibers resulting in carbon-alumina nanocomposites. Thermal analysis, Xray fluorescent microanalysis, Raman spectroscopy, and electrical resistance measurements of these composites show that increasing of synthesis time not only increases the amount of carbon on alumina surface, but also the ordering and density of the carbon layers. Nitrogen adsorption data reveal the decrease of total pore volume with increasing the synthesis time. The obtained composite material could be employed for the preparation of ion-selective membranes with switchable ion transport, electroconductive ceramics, and electrochemical sensors.

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“…Recently, a new type of highly porous ceramic membranes with a conductive coating was suggested [14,15]. The membranes were prepared by vacuum filtration of a colloidal solution of Nafen alumina fibers with a diameter of about 10 nm through a porous substrate and subsequent drying and annealing.…”

Section: Introductionmentioning

confidence: 99%

Modelling of Electrochemically Switchable Ion Transport in Nanoporous Membranes with Conductive Surface

Ryzhkov

Vyatkin

Медведева

2019

Journal of Siberian Federal University. Mathematics &Amp; Physics

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The impact of potential applied to the conductive surface of nanoporous membrane on the membrane potential at zero current is investigated theoretically on the basis of two–dimensional Space–charge model. The membrane separates two reservoirs with different salt concentrations. It is shown that the variation of applied potential from negative to positive values results in the continuous change of membrane selectivity from cation to anion. For equal ion diffusion coefficients, the dependence of membrane potential on the applied potential is an odd function, while for different ion diffusion coefficients it is shifted along the applied potential axis due to contribution of diffusion potential enhanced by the induced charge effect. The decrease of pore radius results in the increase of ionic selectivity and steep transition between cation– selective and anion–selective states when the applied potential is changing

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Preparation and ionic selectivity of carbon-coated alumina nanofiber membranes

Cited by 11 publications

References 45 publications

Modelling of Conductive Nanoporous Membranes with Switchable Ionic Selectivity

Modelling of Conductive Nanoporous Membranes with Switchable Ionic Selectivity

Coupled thermal analysis of carbon layers deposited on alumina nanofibres

Modelling of Electrochemically Switchable Ion Transport in Nanoporous Membranes with Conductive Surface

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