%0 Journal Article
%A Xu, Cheng
%A Zhang, Binbin
%A Wang, Aurelia Chi
%A Zou, Haiyang
%A Liu, Guanlin
%A Ding, Wenbo
%A Wu, Changsheng
%A Ma, Ming
%A Feng, Peizhong
%A Lin, Zhiqun
%A Wang, Zhong Lin
%D 2019
%T Contact-Electrification
between Two Identical Materials: Curvature Effect
%U https://acs.figshare.com/articles/journal_contribution/Contact-Electrification_between_Two_Identical_Materials_Curvature_Effect/7670954
%R 10.1021/acsnano.8b08533.s001
%2 https://ndownloader.figshare.com/files/14250410
%K curvature-dependent charge transfer model
%K contact mode
%K curvature surfaces
%K contact-separation mode triboelectric nanogenerator
%K contact-electrification
%K material
%K curvature-induced energy shifts
%K piece
%X It is known that contact-electrification
(or triboelectrification) usually occurs between two different materials,
which could be explained by several models for different materials
systems (Adv. Mater. 2018, 30, 1706790; Adv. Mater. 2018, 30, 1803968). But contact between two pieces of the chemically
same material could also result in electrostatic charges, although
the charge density is rather low, which is hard to understand from
a physics point of view. In this paper, by preparing a contact-separation
mode triboelectric nanogenerator using two pieces of an identical
material, the direction of charge transfer during contact-electrification
is studied regarding its dependence on curvatures of the sample surfaces.
For materials such as polytetrafluoroethylene, fluorinated ethylene
propylene, Kapton, polyester, and nylon, the positive curvature surfaces
are net negatively charged, while the negative curvature surfaces
tend to be net positively charged. Further verification of the above-mentioned
trends was obtained under vacuum (∼1 Pa) and higher temperature
(≤358
K) conditions. Based on the received data acquired for gentle contacting
cases, we propose a curvature-dependent charge transfer model by introducing
curvature-induced energy shifts of the surface states. However, this
model is subject to be revised if the mutual contact mode turns into
a sliding mode or more complicated hard-pressed contact mode, in which
a rigorous contact between the two pieces of the same material could
result in nanoscale damage/fracture and possible species transfer.
Our study provides a primitive step toward understanding the basics
of contact-electrification.
%I ACS Publications