Citation: Lee, S.-J.; Jung, Y.-J.; Park, J.;
Jang, S.-H. Temperature Detectable
Surface Coating with Carbon
Nanotube/Epoxy Composites.
Nanomaterials 2022, 12, 2369. https://
doi.org/10.3390/nano12142369
Academic Editor: Deepak Kukkar
Received: 5 June 2022
Accepted: 7 July 2022
Published: 11 July 2022
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Article
Temperature Detectable Surface Coating with Carbon
Nanotube/Epoxy Composites
Seung-Jun Lee
1
, Yu-Jin Jung
2
, JeeWoong Park
3,
* and Sung-Hwan Jang
2,4,
*
1
Department of Civil and Environmental Engineering, Hanyang University, Seoul 04763, Korea;
sj5523@hanyang.ac.kr
2
Department of Smart City Engineering, Hanyang University ERICA, Ansan 15588, Korea;
yujin0421@hanyang.ac.kr
3
Department of Civil and Environmental Engineering and Construction, The University of Nevada,
Las Vegas, NV 89154, USA
4
Department of Civil and Environmental Engineering, Hanyang University ERICA, Ansan 15588, Korea
* Correspondence: jee.park@unlv.edu (J.P.); sj2527@hanyang.ac.kr (S.-H.J.)
Abstract:
In the construction and machinery industry, heat is a major factor causing damage and
destruction. The safety and efficiency of most machines and structures are greatly affected by temper-
ature, and temperature management and control are essential. In this study, a carbon nanotube (CNT)
based temperature sensing coating that can be applied to machines and structures having various
structural types was fabricated, and characteristics analysis and temperature sensing performance
were evaluated. The surface coating, which detects temperature through resistance change is made
of a nanocomposite composed of carbon nanotubes (CNT) and epoxy (EP). We investigated the
electrical properties by CNT concentration and temperature sensing performance of CNT/EP coating
against static and cyclic temperatures. In addition, the applicability of the CNT/EP coating was
investigated through a partially heating and cooling experiment. As a result of the experiment,
the CNT/EP coating showed higher electrical conductivity as the CNT concentration increased. In
addition, the CNT/EP coating exhibits high sensing performance in the high and sub
−
zero tempera-
ture ranges with a negative temperature coefficient of resistance. Therefore, the proposed CNT/EP
coatings are promising for use as multi-functional coating materials for the detection of high and
freezing temperatures.
Keywords: carbon nanotube; surface coating; temperature sensing; epoxy
1. Introduction
Temperature is a key parameter for most industries, and temperature sensors account
for a large part of the overall sensor market [
1
]. In addition, according to industrial
development, a temperature sensor is required with capable of responding to complex
structures and various environments. However, in the case of conventional temperature
sensor materials such as silicon diodes and platinum, heat loss occurs when there is not
enough thermal energy, resulting in poor precision or slow response. It is also difficult to
cope with large areas. In order to compensate for the shortcomings of the conventional
temperature sensors, research on new materials or composites is being actively conducted.
Carbon nanotubes (CNT) are widely used as a functional filler, and carbon nanotube
composites are utilized in various industrial fields. The structural morphology of CNT
can be used as a composite mixed with different materials to impart electrical and thermal
conductivity and/or mechanical properties [
2
–
4
]. In particular, the dispersion of these kinds
of nanoparticles in polymeric systems allows to improve thermal stability, photooxidation
resistance, and mechanical properties and simultaneously provides the means to make the
resulting nanocomposite able to manifest functional properties [5,6].
Nanomaterials 2022, 12, 2369. https://doi.org/10.3390/nano12142369 https://www.mdpi.com/journal/nanomaterials
