Investigation of the constancy of the MWCNTs on the fibres surface for manufactured self-sensing composites

Abstract

Different methods have been used to deposit the multi-walled carbon nanotubes (MWCNTs) onto the fibre surface to fabricate self-sensing composites. However, the constancy of the MWCNTs onto the fibre surfaces during infusion processing still unclear. In this study, we have deposited MWCNTs onto the glass fibre surface by two methods to investigate the state of MWCNTs during and after epoxy infusion processing. In the first method, the glass fibres were directly coated with the MWCNTs and in the second method, an adhesive was applied to coat the glass fibre surface before depositing the MWCNTs over it. Rectangular specimens for both types of self-sensing composites were cut from different specified zones and then tested. The results showed that the self-sensing composites with adhesively bonded MWCNTs exhibited more consistent in their properties than the composites where no adhesive was used. In addition, the electrical resistance of both types of self-sensing composites was monitored during the epoxy infusion process. The results showed that the electrical resistance was not obviously affected for composite with non-adhesive bonded MWCNTs and was high for the specimens where the MWCNTs were not adhesively bonded. Moreover, the numerical study was also conducted and the results indicated that the relationship between the volume fraction of the MWCNTs and their tunnelling distance was an inverse. The current study proves evidence that the properties of the self-sensing composites are strongly dependent on the method that used to deposit the MWCNTs on the surface of glass fibres layers.