EconPapers    
Economics at your fingertips  
 

pH drives electron density fluctuations that enhance electric field-induced liquid flow

S. Pullanchery, S. Kulik, T. Schönfeldová, C. K. Egan, G. Cassone, A. Hassanali () and S. Roke ()
Additional contact information
S. Pullanchery: School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL)
S. Kulik: School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL)
T. Schönfeldová: School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL)
C. K. Egan: International Centre for Theoretical Physics
G. Cassone: Italian National Research Council (IPCF-CNR)
A. Hassanali: International Centre for Theoretical Physics
S. Roke: School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL)

Nature Communications, 2024, vol. 15, issue 1, 1-13

Abstract: Abstract Liquid flow along a charged interface is commonly described by classical continuum theory, which represents the electric double layer by uniformly distributed point charges. The electrophoretic mobility of hydrophobic nanodroplets in water doubles in magnitude when the pH is varied from neutral to mildly basic (pH 7 → 11). Classical continuum theory predicts that this increase in mobility is due to an increased surface charge. Here, by combining all-optical measurements of surface charge and molecular structure, as well as electronic structure calculations, we show that surface charge and molecular structure at the nanodroplet surface are identical at neutral and mildly basic pH. We propose that the force that propels the droplets originates from two factors: Negative charge on the droplet surface due to charge transfer from and within water, and anisotropic gradients in the fluctuating polarization induced by the electric field. Both charge density fluctuations couple with the external electric field, and lead to droplet flow. Replacing chloride by hydroxide doubles both the charge conductivity via the Grotthuss mechanism, and the droplet mobility. This general mechanism deeply impacts a plethora of processes in biology, chemistry, and nanotechnology and provides an explanation of how pH influences hydrodynamic phenomena and the limitations of classical continuum theory currently used to rationalize these effects.

Date: 2024
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41467-024-50030-8 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:15:y:2024:i:1:d:10.1038_s41467-024-50030-8

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-024-50030-8

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().

 
Page updated 2025-03-19
Handle: RePEc:nat:natcom:v:15:y:2024:i:1:d:10.1038_s41467-024-50030-8