Assessing the electrical behaviour of MWCNTs/epoxy nanocomposite for strain sensing. (1st November 2017)

• Record Type: Journal Article
• Authors: Bouhamed, Ayda; Al-Hamry, Ammar; Müller, Christian; Choura, Slim; Kanoun, Olfa
• Is Part Of: Composites. Number 128(2017)
• Page Start: 91
• Page End: 99
• Publication Date: 2017-11-01
• Subjects: MWCNTs/epoxy nanocomposite -- Electrical properties -- Piezoresistive behaviour -- Temperature dependency -- Humidity dependency; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2017.07.005
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: Nanocomposite sensors are gaining importance not only because they have low cost, but also because of the possibility to adjust sensor properties to the requirements of certain applications. In this paper, we focus on the realization of multiwalled carbon nanotubes (MWCNTs)/epoxy nanocomposite for strain sensing applications. We propose to use a simple direct mixing process to realize randomly distributed nanocomposite films with different concentration ranging from 0.3 to 0.75 wt.% and thicknesses. Dispersions were firstly examined using scanning electron microscopy (SEM). The results show a good homogeneity and distribution of the MWCNTs in agreement with the reduced electrical resistance when increasing the CNTs content and film thickness. Additionally, it has been demonstrated that the piezoresistive characteristic of nanocomposites depends principally on the CNTs content and film thickness. A higher magnitude of change in resistance is observed for the sample with low volume fraction and thickness leading to a gauge factor 14.19 with a linearity correlation of R 2 = 0.9414. In this work, we address also the effect of environmental changes by characterization of temperature, humidity and stability behaviour. These films show higher sensitivity to temperature and humidity at lower MWCNTs concentration. The film resistance shows a good stability under ambient conditions. Graphical abstract: MWCNTs∖epoxy nanocomposite based strain sensor is studied in this work. Influence of MWCNTs concentration and film thickness on the performance of the sensor are investigated in this work. Morphological characterization is performed using SEM investigation to identifier the quality of the dispersion. Strain sensor performance such as electrical, electro-mechanical, electrical change under harsh environment and stability measurements are performed to characterize the sensitivity, durability and stability, to identify the different aspects that change the sensor performance and to select the suitable composition. Highlights: MWCNTs∖epoxy nanocomposite is prepared using direct mixing method for the development of strain sensor. Scanning electron microscopy is used to investigate the effect of MWCNTs concentration on the quality of dispersions. Electrical and piezoresistive characterization are performed to determine the impact of both film thickness and concentration on the sensor performance. Deeply investigation of the impact of harsh environment on the electrical behaviour of nanocomposite is addressed. The stability of thin films under isothermal condition is addressed.