Contact electrification efficiency dependence on surface energy at the water-solid interface

Liquid-solid contact electrification is a useful mechanism to harvest wasted micromechanical energy. In this study, we investigate how the surface properties of a solid substrate affect contact electrification efficiency. Substrate surfaces were modified from hydrophilic to hydrophobic by changing t...

Full description

Saved in:
Bibliographic Details
Published in:Applied physics letters 2018-07, Vol.113 (2)
Main Authors: Shahzad, Amir, Wijewardhana, K. Rohana, Song, Jang-Kun
Format: Article
Language:English
Subjects:
Aliphatic compounds
Applied physics
Charge density
Dependence
Drying
Efficiency
Electrification
Electronegativity
Energy harvesting
Properties (attributes)
Self-assembled monolayers
Self-assembly
Silicon dioxide
Substrates
Surface energy
Surface properties
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Liquid-solid contact electrification is a useful mechanism to harvest wasted micromechanical energy. In this study, we investigate how the surface properties of a solid substrate affect contact electrification efficiency. Substrate surfaces were modified from hydrophilic to hydrophobic by changing the density of self-assembled monolayers (SAMs) on a SiO2 surface. A substrate with a partially-covered SAM exhibited superior performance. The partially-covered SAM substrate is hydrophobic enough to induce quick dewetting of water from the surface and sufficiently electronegative to induce a high charge density on the surface. The quick dewetting results from the aliphatic tail groups of the SAM and -OH groups make the SiO2 surface electronegative; these two competing properties can be simultaneously obtained by optimizing the SAM density. Our findings contribute to the understanding of contact electrification in liquid-solid-type energy-harvesting devices and advance the strategies to maximize the electrification efficiency by optimizing surface geometries and properties.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.5038605