Densely packed, highly strain sensitive carbon nanotube composites with sufficient polymer penetration

Abstract

The nano-porous structure of CNT film severely limits the penetration of polymer resin for advanced composites. To solve this critical issue, we propose a method which could not only uniformly infiltrate resin into CNT films along thickness direction but also ensure sufficient polymer penetration for the fabrication of CNT film/epoxy composites. The resultant composites revealed an outstanding improvement of 352% and 664% accordingly for tensile strength and Young’s modulus. It also showed 8 times enhancement of tensile toughness compared to that of the pristine CNT film. Furthermore, the high sensitivity (gauge factor ~ 4.6) with a linear piezo resistive response within a large strain (~5%) and the stable sensing reversibility, demonstrated the excellent strain sensing properties of the produced composites. Therefore, our study innovatively proposes this vacuum-assisted filtration method to obtain the strong fibre-matrix interface interaction inside the dense CNT assemblies as well as other nanomaterials.