Self-Propulsion of Active Colloids via Ion Release: Theory and Experiments

De Corato, Marco (Universidad de Zaragoza) ; Arqué, Xavier ; Patiño, Tania ; Arroyo, Marino ; Sánchez, Samuel ; Pagonabarraga, Ignacio

Resumen: We study the self-propulsion of a charged colloidal particle that releases ionic species using theory and experiments. We relax the assumptions of thin Debye length and weak nonequilibrium effects assumed in classical phoretic models. This leads to a number of unexpected features that cannot be rationalized considering the classic phoretic framework: an active particle can reverse the direction of motion by increasing the rate of ion release and can propel even with zero surface charge. Our theory predicts that there are optimal conditions for self-propulsion and a novel regime in which the velocity is insensitive to the background electrolyte concentration. The theoretical results quantitatively capture the salt-dependent velocity measured in our experiments using active colloids that propel by decomposing urea via a surface enzymatic reaction.

Idioma: Inglés

DOI: 10.1103/PhysRevLett.124.108001

Año: 2020

Publicado en: Physical Review Letters 124, 10 (2020), 108001 [6 pp.]
ISSN: 0031-9007

Factor impacto JCR: 9.161 (2020)

Categ. JCR: PHYSICS, MULTIDISCIPLINARY rank: 7 / 84 = 0.083 (2020) - Q1 - T1

Factor impacto SCIMAGO: 3.688 - Physics and Astronomy (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/EC/H2020/712754/EU/Postdoctoral Programme in Bioengineering Excellence Scientific Training/BEST
Financiación: info:eu-repo/grantAgreement/ES/MINECO/SEV-2014-0425

Tipo y forma: Article (PostPrint)

Área (Departamento): Área Mecánica de Fluidos (Dpto. Ciencia Tecnol.Mater.Fl.)