Slide electrification: charging of surfaces by moving water drops

Abstract

<p>We investigate the charge separation caused by the motion of a water drop across a hydrophobic, insulating solid surface.</p>

Autoren

Amy Z Stetten
Dmytro S Golovko
Stefan AL Weber
Hans-Jürgen Butt

DOI

10.1039/c9sm01348b

eISSN

1744-6848

ISSN

1744-683X

Ausgabe der Veröffentlichung

43

Zeitschrift

Soft Matter

Sprache

en

Online publication date

2019

Paginierung

8667 - 8679

Status

Published online

Herausgeber

Royal Society of Chemistry (RSC)

Herausgeber URL

http://dx.doi.org/10.1039/c9sm01348b

Datum der Datenerfassung

2024

Titel

Slide electrification: charging of surfaces by moving water drops

Ausgabe der Zeitschrift

15

Data source: Crossref

Abstract

We investigate the charge separation caused by the motion of a water drop across a hydrophobic, insulating solid surface. Although the phenomenon of liquid charging has been consistently reported, these reports are primarily observational, results are difficult to reproduce, and no quantitative theory has been developed. In this work, we address both the experimental and theoretical sides of this problem. We reproducibly measure the charge gained by water drops sliding down a substrate, and we outline an analytical theory to describe this charging process. As an experimental system, we choose water drops moving down an inclined plane of glass hydrophobized with perfluoro octadecyltrichlorosilane (PFOTS). On this surface, sliding drops gain a positive charge. We observe charge saturation in three variables: increasing drop number, increasing interval between drops, and increasing drop-sliding length. These charge saturations indicate a limited "storage capacity" of the system, as well as a gradual discharging of the surface. To explain these results, we theorize that some fraction of the charge in the Debye layer is transferred to the surface rather than being neutralized as the drop passes. This fraction, or "transfer coefficient", is dependent on the electric potentials of surface and drop. All of our experimental charge saturation results can be interpreted based on the proposed theory. Given that nearly every surface in our lives comes in contact with water, this water-dependent surface charging may be a ubiquitous process that we can begin to understand through the proposed theory.

Addresses

Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. butt@mpip-mainz.mpg.de.

Autoren

Amy Z Stetten
Dmytro S Golovko
Stefan AL Weber
Hans-Jürgen Butt

DOI

10.1039/c9sm01348b

eISSN

1744-6848

Externe Identifier

PubMed Identifier: 31528956

Funding acknowledgements

European Research Council: SUPRO 340391

Open access

false

ISSN

1744-683X

Ausgabe der Veröffentlichung

43

Zeitschrift

Soft matter

Sprache

eng

Medium

Print-Electronic

Online publication date

2019

Paginierung

8667 - 8679

Datum der Veröffentlichung

2019

Status

Published

Publisher licence

CC BY

Datum der Datenerfassung

2019

Titel

Slide electrification: charging of surfaces by moving water drops.

Sub types

Journal Article

Ausgabe der Zeitschrift

15

Data source: Europe PubMed Central

Abstract

We investigate the charge separation caused by the motion of a water drop across a hydrophobic, insulating solid surface. Although the phenomenon of liquid charging has been consistently reported, these reports are primarily observational, results are difficult to reproduce, and no quantitative theory has been developed. In this work, we address both the experimental and theoretical sides of this problem. We reproducibly measure the charge gained by water drops sliding down a substrate, and we outline an analytical theory to describe this charging process. As an experimental system, we choose water drops moving down an inclined plane of glass hydrophobized with perfluoro octadecyltrichlorosilane (PFOTS). On this surface, sliding drops gain a positive charge. We observe charge saturation in three variables: increasing drop number, increasing interval between drops, and increasing drop-sliding length. These charge saturations indicate a limited "storage capacity" of the system, as well as a gradual discharging of the surface. To explain these results, we theorize that some fraction of the charge in the Debye layer is transferred to the surface rather than being neutralized as the drop passes. This fraction, or "transfer coefficient", is dependent on the electric potentials of surface and drop. All of our experimental charge saturation results can be interpreted based on the proposed theory. Given that nearly every surface in our lives comes in contact with water, this water-dependent surface charging may be a ubiquitous process that we can begin to understand through the proposed theory.

Autoren

Amy Z Stetten
Dmytro S Golovko
Stefan AL Weber
Hans-Jürgen Butt

Autoren-URL

https://www.ncbi.nlm.nih.gov/pubmed/31528956

DOI

10.1039/c9sm01348b

eISSN

1744-6848

Ausgabe der Veröffentlichung

43

Zeitschrift

Soft Matter

Sprache

eng

Country

England

Paginierung

8667 - 8679

Datum der Veröffentlichung

2019

Status

Published

Datum, an dem der Datensatz öffentlich gemacht wurde

2019

Titel

Slide electrification: charging of surfaces by moving water drops.

Sub types

Journal Article

Ausgabe der Zeitschrift

15

Data source: PubMed

Slide electrification: charging of surfaces by moving water drops

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