Overlimiting convection at a heterogeneous cation-exchange membrane studied by particle image velocimetry

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F22%3A43925229" target="_blank" >RIV/60461373:22340/22:43925229 - isvavai.cz</a>

Alternative codes found

RIV/49777513:23640/22:43965954

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0376738821009881?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0376738821009881?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.memsci.2021.120048" target="_blank" >10.1016/j.memsci.2021.120048</a>

Result language

angličtina

Original language name

Overlimiting convection at a heterogeneous cation-exchange membrane studied by particle image velocimetry

Original language description

Electroconvection and gravitational convection are recognized as the primary mechanisms driving overlimiting currents in ion-exchange systems. Here, we use particle image velocimetry (PIV) to characterize the convection on a small piece of a commercially available heterogeneous cation-exchange membrane. We perform chronoamperometric measurements under various experimental conditions and simultaneously record the developed convection at the membrane-electrolyte solution interface using tracking particles. The convection is observed independently in horizontal and vertical planes, capturing flow fields pertinent to electroconvection and gravitational convection. PIV analysis computes velocity vector fields we employ to calculate the volumetric flow rate through a virtual semi-cylindrical wall around the membrane. The volumetric flow rate represents a way how to quantify the intensity of electroconvection. The electroconvection recorded on the horizontal plane manifests itself as a local short-range chaotic whirring localized at the membrane surface superimposed by two long-range counter-current vortices. The volumetric flow rate associated with the two counter-current vortices almost linearly increases with voltage and decreases with increasing concentration. The stagnant points of the vortices localize from 100 to 450 μm away from the membrane. The convection observed on the vertical plane occurs as a result of electroconvection and gravitational convection. We show that gravitational convection eventually dominates and produces an upward-directed intensive flow with similar values of characteristic velocities as the electroconvection. The development of the gravitational convections is approximately one order of magnitude slower (on the order of seconds) than that of electroconvection (on the order of hundreds of milliseconds).

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20401 - Chemical engineering (plants, products)

Project

<a href="/en/project/GA18-13491S" target="_blank" >GA18-13491S: Interactions of charged polymers with heterogeneous ion-exchange membranes</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Membrane Science

ISSN

0376-7388

e-ISSN

1873-3123

Volume of the periodical

643

Issue of the periodical within the volume

MAR 1 2022

Country of publishing house

BE - BELGIUM

Number of pages

8

Pages from-to

120048

UT code for WoS article

000744265900001

EID of the result in the Scopus database

2-s2.0-85118877099