Visualization of Concentration Gradients and Colloidal Dynamics under Electrodiffusiophoresis

Autor:	Kun Wang, Behrouz Behdani, Carlos Silvera Batista
Rok vydání:	2022
Předmět:	Electrochemistry General Materials Science Surfaces and Interfaces Condensed Matter Physics Spectroscopy
Zdroj:	Langmuir. 38:5663-5673
ISSN:	1520-5827 0743-7463
DOI:	10.1021/acs.langmuir.2c00252
Popis:	In this work, we present an experimental study of the dynamics of charged colloids under direct currents and gradients of chemical species (electrodiffusiophoresis). In our approach, we simultaneously visualize the development of concentration polarization and the ensuing dynamics of charged colloids near electrodes. With the aid of confocal microscopy and fluorescent probes, we show that the passage of current through water confined between electrodes, separated about a hundred microns, results in significant pH gradients. Depending on the current density and initial conditions, steep pH gradients develop, thus becoming a significant factor in the behavior of charged colloids. Furthermore, we show that steep pH gradients induce the focusing of charged colloids away from both electrodes. Our results provide the experimental basis for further development of models of electrodiffusiophoresis and the design of non-equilibrium strategies for materials fabrication.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8b28364bf7ddaaed3bce523310837dfd https://doi.org/10.1021/acs.langmuir.2c00252 Zobrazit plný text záznamu