Comparisons Among Electrical and Rheological Properties of Melt-Mixed Composites Containing Various Carbon Nanostructures

Abstract

The present investigation compares different carbon-based nanoscaled materials with regard to their effectiveness in producing thermoplastic polymers with antistatic and electrically conductive behavior. The dispersed phases are carbon black (CB) as spherical particles, multiwalled carbon nanotubes (MWNT) as fiber-like filler, and expanded graphite (EG) as platelet-like filler. Each was incorporated into polycarbonate by small-scale melt mixing. The electrical percolation concentrations were found to be 2 wt% for MWNT, 4 wt% for EG, and 8.75 wt% for CB which parallels the aspect ratios of the fillers. For EG a strong dependence of morphology and electrical resistivity on mixing time was observed, indicating a structural change/destruction during intensive shear mixing. Rheological percolation thresholds were found to be lower than electrical percolation threshold for the MWNT and CB, but similar in the case of EG. The general impact on complex melt viscosity decreases in the order MWNT, CB, EG. For EG, at higher loadings (above 4wt%) the viscosity increase with filler content is delayed as is the decrease in resistivity.

Eco‐friendly conductive polymer nanocomposites (CPC) for solar absorbers design

“…From the rheological point of view, this results in a decrease of the polymer chains’ mobility owing to polymer–CNT interaction, leading to the adsorption of the polymer chains on CNT surface. Similar results were also reported in the literature for CNT dispersed in poly(propylene), poly(methyl methacrylate) and poly(carbonate) matrices.…”

“…Finally, these rheological results demonstrate that the CNT network formation is easier in PLA than in PA12 matrix, which is also expected to have consequences on electric and thermal conductivities, as it will be confirmed in the following paragraphs.…”

The Role of Selectively Located Commercial Graphene Nanoplatelets in the Electrical Properties, Morphology, and Stability of EVA/LLDPE Blends

“…When the GN content is 2.2 vol%, both blends presented very similar rheological behavior and morphology, in terms of characteristic domain size ξ, but remarkably different electrical conductivity: 1.10 −12 S m −1 for the blend prepared from EVA MB and 4.10 −6 S m −1 for the blend prepared from LLDPE MB. As mentioned above, the G′ plateau at low frequencies (Figure a) can be explained by the formation of a solid GN network but that does not necessarily lead to a parallel increase in conductivity because the rheological percolation of this network occurs before the electrical percolation . Even electrically insulating composites, which are close to the electrical percolation, can still present a rheological percolation.…”

Tailoring selectivity of sprayed carbon nanotube sensors (CNT) towards volatile organic compounds (VOC) with surfactants

“…In particular, carbon nanotubes (CNT) based nanocomposites have been actively studied in the recent years because of their attractive electronic [16], mechanical [17], rheological [18], thermal [19], structural [20] and optical properties [21]. For instance, 60 CNT based gas sensors were found to exhibit a remarkable sensitivity towards gases such as NO2, NH3, H2, O2, CO, CO2 [22].…”