Structure-Properties Relationships of Nanocomposites Based on Polyethylene Oxide and Anisometric Nanoparticles

Abstract

The electrical properties of systems based on polyethylene oxide (PEO), carbon nanotubes (CNTs), and organoclays were studied using the methods of X-ray diffraction analysis, optical microscopy, and impedance spectroscopy. It is established that the introduction of nanofillers into the PEO matrix leads to a significant reduction in its degree of crystallinity. For systems filled with CNTs, a percolation transition is observed, which was analyzed in the framework of the scaling approach. It was found that the structure of composites that contain organoclays significantly depends on their type. For systems containing montmorillonite, the process of intercalation is observed, and for systems filled with laponite, there is exfoliation of organoclay. It is shown that when organomodified laponite (OLP) is introduced into the system, the percolation threshold is shifted to the region of lower CNT concentrations. At the same time, loosening of aggregates from CNT is observed. Modeling of impedance spectra for systems based on PEO by the method of equivalent circuits is carried out. It is established that the introduction of OLP more than 0.4% into the system leads to a significant reduction in electrical conductivity. This effect is explained by the fact that the OLP plates form their own network and prevent the formation of direct contacts between nanotubes.