Low viscosity processing using hybrid CNT-coated silica particles to form electrically conductive epoxy resin composites

Abstract

Hybrid particles of multiwall carbon nanotubes (CNTs) grafted onto silica gel were shown to provide a low viscosity processing route to forming electrically-conductive epoxy resin composites. Rheological studies showed the viscoelastic shear moduli of epoxy resin suspensions containing these particles (named SG6_3) remained within the same order of magnitude as that of the neat resin at ≤5 wt.% loading (containing up to 1.65 wt.% of grafted CNTs). Whereas, the addition of 1.65 wt.% of discrete (nongrafted) CNTs into the same resin increased shear moduli by up to seven orders of magnitude. The complex viscosities of suspensions containing ≤5 wt.% of SG6_3 remained essentially unchanged, whereas an increase of up to five orders of magnitude resulted upon the addition of 1.65 wt.% of nongrafted CNTs. Whilst rheological studies showed SG6_3 did not form a percolated network at levels ≤5 wt.%, addition of only 2 wt.% (containing 0.66 wt.% CNT) was found to form an electrically-conductive percolated network in an epoxy resin composite with conductivity ~ 10 -4 S/m.

Synergistic effect of graphene and carbon nanotube on lap shear strength and electrical conductivity of epoxy adhesives

“…CNT is regarded as a one‐dimensional (1D) tube possessing outstanding mechanical properties and high aspect ratio ranging from 30 to more than thousands . Since the discovery of CNTs in 1991, they attracted researchers' interest to use them in various applications such as reinforcement filler in developing superior composite . However, most of CNTs exist in bundles and/or agglomerates and it is challenging to uniformly disperse them inside the host matrix.…”

Improvement of Fracture Toughness in Epoxy Nanocomposites through Chemical Hybridization of Carbon Nanotubes and Alumina

“…The world of composite materials is expanding due to its new potential of building various kinds of hybrid compounds. These hybrid compounds provide intriguing challenges and opportunities for chemists, physicists, biologists, engineers, and material scientists [ 1 , 2 ]. The hybrid concept is a simple extension of the composite principle of combining more than one reinforcement material.…”

Preparation and Properties of Highly Electroconductive and Heat-Resistant CMC/Buckypaper/Epoxy Nanocomposites

“…The nanocomposite with four-layered CMC/buckypaper possessed the highest storage modulus of 1934 MPa, which was approximately 60% higher than that of neat polymer (1185 MPa) below the range of glass transition region, whereas there were no significant differences in the rubbery plateau region. This increased storage modulus is attributed to the ultrahigh elastic modulus of CNTs (over 1 TPa) [30,31] and the effect of the homogeneous CMC/buckypapers in an epoxy matrix coupled with significant carbon nanotube/polymer interactions, resulting in the effective knotting and tangling between CNTs and epoxy matrix chains [32]. The glass transition temperature (Tg) of neat epoxy polymer is 130.9 °C, determined from the peak position of the tan d curves.…”