Detonation Nanodiamonds and Carbon Nanotubes as Reinforcements in Epoxy Composites—A Comparative Study

Abstract

A comparative study between detonation nanodiamonds (DNDs) and carbon nanotubes (CNTs) as low concentration additives to epoxy composites is presented. The dispersibility of the different nanocarbons in resin solutions leading to uniform composite formation is also discussed. Significant increase in glass transition temperature was observed, which were 37 °C and 17 °C for DNDs and CNTs, respectively. Unlike the pure epoxy, the fractured surface of both composites showed resistance to crack propagation. Tensile properties of DNDs and CNTs composites showed enhancement of 6.4% and 2.9%, respectively. The nanocomposites also showed an increase in microhardness by 41% for DNDs and 12% for CNTs, and a decrease in electrical resistivity by 2 orders of magnitude, with the CNTs showing lower resistivity. In general, the DNDs were found to be quite effective and at the reported concentrations between 0.1% and 0.5% and showed superior enhancement compared to the CNTs.

Mechanical performance of epoxy matrix hybrid nanocomposites containing carbon nanotubes and nanodiamonds

“…In contrast, reports are also available which show no significant effect upon tensile strength even after adding 1wt% MWCNTs [63]. NDs are reported to increase the tensile strength of epoxy matrix [12,48,56,59]; for example, a 52.7% increase in tensile strength was observed in a study by adding only 0.3wt% NDs [55]. Fig.…”

“…10 on Mohs scale [9], NDs are expected to have a pronounced effect on the hardness of epoxy matrix composites [8,47,56,61]. In comparison, MWCNTs also increase the hardness of polymeric matrix composites significantly [58,59]. However, it is to be mentioned here that neither the hardness value of MWCNTs is available due to its nanometer size nor it can be estimated by relating it to graphite due to change in their structural morphology, i.e.…”

“…Both NDs and MWCNTs are reported to increase the hardness of epoxy matrix composites when incorporated individually in limited quantities, i.e. 0.1wt% [59]. However, in large concentrations, NDs significantly increase the hardness of composites; for example, 270% increase in Vickers hardness and 300% increase in Meyers hardness have been reported by incorporating 25vol% NDs in epoxy matrix composites [1].…”

“…planer graphene sheets in graphite to rolled graphene sheets in MWCNTs. Nevertheless, a significant increase in the hardness of epoxy matrix composites is found by the addition of MWCNTs [59]. Hardness actually measures the resistance to deformation and penetration of a material under concentrated applied load.…”

Nanodiamond–polymer composites

“…The nanocomposites also showed an increase in microhardness by 41 % for NDs and 12 % for CNTs. The authors conclude that at similar nanofiller concentrations in the range 0.1 -0.5 wt.% NDs showed superior enhancement compared to the CNTs in epoxy matrix composites 64 .…”