Electrical and optical properties of polyamide 6 nanocomposites with multi-walled carbon nanotubes

Abstract

In this work, quantum chemical modeling, electrical conductivity, Raman scattering, and photoluminescence of polyamide 6 nanocomposites with multi-walled carbon nanotubes (0-2.5 vol.%) were investigated. It was shown that the concentration dependence of the electrical conductivity obeys the percolation theory and has the value of percolation threshold 1.41 vol.%. The conductivity value of the composite at 2.5 vol.% nanotubes is 1.1*10-3 S/cm. It was found that in PA6 nanocomposites filled with MWCNT an increase in the concentration of nanotubes from 0.001 to 0.015 vol.%, namely in the pre-percolation region of electrical conductivity, due to a significant restructuring of the Raman spectra, which consists in a shift of the vibrational modes of the methylene groups CH2 and amide I, as well as in a change of their relative intensities. From the photoluminescence spectra of PA6-MWCNT, it can be seen, that the carbon nanotubes largely determine the conformational changes in the polymer matrix and have little effect on the defective structure of the polymer itself. The goal: to establish the mechanisms of electrical conductivity and the interaction of nanotubes with polyamide macromolecules and its influence on the electronic and optical properties of nanocomposites of polyamide multi-walled carbon nanotubes.