Characterization of slug flow of two aqueous phases by electrochemical impedance spectroscopy in a fluidic chip

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23640%2F18%3A43964124" target="_blank" >RIV/49777513:23640/18:43964124 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60461373:22340/18:43915898

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0167931718301138#" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0167931718301138#</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.mee.2018.03.003" target="_blank" >10.1016/j.mee.2018.03.003</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Characterization of slug flow of two aqueous phases by electrochemical impedance spectroscopy in a fluidic chip

Popis výsledku v původním jazyce

We adopted a method of electrochemical impedance spectroscopy (EIS) for the characterization of slug flow of two immiscible aqueous phases in a flow channel. The impedance response (both magnitude and phase shift) of the two-phase system is measured as a function of time at selected frequencies. The presence of slugs or a continuous phase at a pair of parallel facing electrodes can be determined under various signal frequencies mainly due to a significant difference in the electrolytic conductivities of both phases. We found that EIS data are sensitive to the total flowrate at low signal frequencies. Further, we suggested an equivalent electric circuit that takes into account all capacitances and resistances emerging between the two sensing electrodes. We determined the values of these elements by fitting a theoretical model to the experimental data. The obtained values of resistances were used to estimate the thicknesses of the wall film of the continuous phase that is present between a slug of the dispersed fluid and a channel wall. The estimates given by the EIS method were successfully verified by microscopic observation and an available hydrodynamic correlation. The developed EIS method represents an original approach to the estimation of wall film thickness applicable to the efficient control of various droplet-based microfluidic devices such as microreactors and microextractors working with aqueous two-phase systems.

Název v anglickém jazyce

Characterization of slug flow of two aqueous phases by electrochemical impedance spectroscopy in a fluidic chip

Popis výsledku anglicky

We adopted a method of electrochemical impedance spectroscopy (EIS) for the characterization of slug flow of two immiscible aqueous phases in a flow channel. The impedance response (both magnitude and phase shift) of the two-phase system is measured as a function of time at selected frequencies. The presence of slugs or a continuous phase at a pair of parallel facing electrodes can be determined under various signal frequencies mainly due to a significant difference in the electrolytic conductivities of both phases. We found that EIS data are sensitive to the total flowrate at low signal frequencies. Further, we suggested an equivalent electric circuit that takes into account all capacitances and resistances emerging between the two sensing electrodes. We determined the values of these elements by fitting a theoretical model to the experimental data. The obtained values of resistances were used to estimate the thicknesses of the wall film of the continuous phase that is present between a slug of the dispersed fluid and a channel wall. The estimates given by the EIS method were successfully verified by microscopic observation and an available hydrodynamic correlation. The developed EIS method represents an original approach to the estimation of wall film thickness applicable to the efficient control of various droplet-based microfluidic devices such as microreactors and microextractors working with aqueous two-phase systems.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Projekt

<a href="/cs/project/LO1402" target="_blank" >LO1402: CENTEM+</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

MICROELECTRONIC ENGINEERING

ISSN

0167-9317

e-ISSN

—

Svazek periodika

194

Číslo periodika v rámci svazku

JUL 5 2018

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

7

Strana od-do

89-95

Kód UT WoS článku

000433265900016

EID výsledku v databázi Scopus

2-s2.0-85044131761