Uniaxial strengthening of the polyamide film by the aligned carbon nanotubes

Abstract

The incorporation of carbon nanotubes (CNTs) into a polymer matrix can significantly improve its mechanical and electrical properties. In the case of the aligned CNTs in a polymer matrix, the mechanical properties along the alignment direction are significantly enhanced comparing to the perpendicular direction. Hence, the CNT alignment is a crucial step in the fabrication of a CNT-reinforced nanocomposite. The aligned growth of the CNTs or a post-incorporation CNT alignment are two options mainly used. In our work, we present a facile and scalable preparation method for the polyamide nanocomposite film containing a self-assembled layer of the aligned CNTs. The nanocomposite was prepared by spraying the polyamide solution onto a Langmuir film of the aligned CNTs. The nanocomposite films were characterized by the tensile strength measurements, Raman spectroscopy and broadband dielectric spectroscopy. The measured tensile strength along the CNT alignment was up to 12× higher than that in the perpendicular direction and the electrical conductivity increased from 10−15 S/cm to 10-7 S/cm. Our results show that even a rather simple method can provide a substantial enhancement of mechanical and electrical properties of a polymer by incorporation of CNTs.