Solvent-induced inversion of colloidal aggregation during electrophoretic deposition.

by DeMoulpied, Justin R.; Killenbeck, Jessica A.; Schichtl, Zebulon G.; Sharma, Babloo; Striegler, Susanne; Coridan, Robert H.

Electrophoretic deposition of colloidal particles is a practical system for the study of crystn. and related phys. phenomena. The aggregation is driven by the electroosmotic flow fields generated by the polarization of the electrode-particle-electrolyte interface. Here, we report on the electrochem. control of aggregation and repulsion in the electrophoretic deposition of colloidal microspheres. The nature of this transition depends solely on the compn. of the solvent. The obsd. behavior switches between elec. field-driven aggregation in water to elec. field-driven repulsion in ethanol for otherwise identical systems of colloidal microspheres. This work uses optical microscopy-derived particle and a recently developed particle insertion method-approach to ext. the effective interparticle potentials as a function of the solvent and electrode potential at the electrode interface. This approach can be used to understand the phase behavior of these systems based on the observable particle positions rather than a detailed understanding of the electrode-electrolyte microphysics.

Journal
ChemRxiv
Year
2022
Start Page
1-21
URL
https://dx.doi.org/10.26434/chemrxiv-2022-dz3j4
ISBN/ISSN
2573-2293
DOI
10.26434/chemrxiv-2022-dz3j4