Dielectric and Electrical Properties of WS₂ Nanotubes/Epoxy Composites and Their Use for Stress Monitoring of Structures

Abstract

The dielectric and electrical characteristics of the semiconductive WS2 nanotubes/epoxy composites were studied as a function of the nanotubes concentration and the pressure applied during their molding. In addition, the ability of WS2 nanotubes to serve as stress sensors in epoxy based nanocomposites, for health-monitoring applications, was studied. The nanocomposite elements were loaded in three-point bending configuration. The direct current was monitored simultaneously with stress-strain measurements. It was found that, in nanocomposites, above the percolation concentrations of the nanotubes, the electrical conductivity increases considerably with the applied load and hence WS2 nanotubes can be potentially used as sensors for health monitoring of structural components.

Dielectric Properties of Epoxy-Matrix Composites with Tungsten Disulfide Nanotubes

“…In the earlier studies, it was established that the percolation threshold in WS 2 /epoxy composites can be close to 25 vol% [20] and in polyurethane/WS 2 composites-larger than 2 wt% [21]. No electrical percolation for polyvinylidene fluoride (PVDF) composites with WS 2 was observed in reference [20]; however, in this work was established that pellets of WS 2 nanotubes are quite conductive.…”

“…All composite preparation technology conditions were varied in order to obtain the biggest complex dielectric permittivity value of samples at room temperature; it was determined that the above listed conditions are optimal. These conditions are different from those, which applied for epoxy/WS 2 composite preparation in [21].…”

“…Despite the fact that the electrical conductivity of WS 2 nanotubes is about 10 3 S/m [16,17] and these nanotubes can be used in transistors, photodetectors, and other electronic devices [2,18,19], the amount of publications on electromagnetic properties of polymer composites with WS 2 nanotubes is still very small [20][21][22]. Therefore, being of nanosize, having excellent mechanical and electrical properties, and possessing good dispersion and adhesion to polymers, inorganic nanotubes of WS 2 could be a good candidate for broadband electromagnetic composite applications.…”

Poly(L-lactic acid) Reinforced with Hydroxyapatite and Tungsten Disulfide Nanotubes

“…However, both PLLA and HA and their composites suffer from low toughness, which limits their application in the human body [15,16]. Reinforcing the PLLA/HA composite with nanotubes of WS 2 (INT-WS 2 ) can remedy this disadvantage [6,17,18]. The INT-WS 2 are multiwall nanostructures 1-20 µm long with diameters of 30-150 nm (aspect ratios of 50-100 and even larger).…”

Parametric Analysis of Electrical Conductivity of Polymer-Composites

“…This polymer-composite electrolyte is suitable for electrochemical, and magnetic devices. Furthermore, nanocomposites of inorganic materials for health monitoring sensor was investigated by [25]. The fast electrical response of the composite when subjected to mechanical stress, revealed that the material is suitable for the manufacturing of health monitoring sensors.…”