Hybrid based on graphene nanoplatelets and carbon nanotubes obtained in a single‐step approach and its reinforcement effect in an epoxy matrix

Abstract

A hybrid based on graphene nanoplatelets and carbon nanotubes (G‐CNT) is obtained through direct exfoliation of graphite in a liquid medium, and tested as reinforcement material in epoxy resin. CNT act as exfoliation material in contact with graphite under ultrasound irradiation, and the thickness of graphite decreases to produce graphene nanoplatelets in an easy one‐step method. The morphology of the hybrid, is observed through transmission electron microscopy micrographs exhibiting delamination of graphite. XRD, UV–vis, and atomic force microscopy (AFM) results provide evidence of the exfoliation of graphite by interaction with CNT. Ultrasonic process does not generate additional oxygenated groups on carbon structures, as it is supported by XPS spectra; and the disorder in the carbon structures detected in Raman spectra is attributed to defects originated by some fragmentations. Epoxy nanocomposites incorporating 0.3 wt% of G‐CNT display the highest enhancement in storage modulus (~2706 MPa), glass transition region increases meaning higher thermal stability, and glass transition temperature increases until 119°C. Impact resistance also enhances with 0.3 wt% of G‐CNT, obtaining ~95% of increment. The hybrid obtained by exfoliating graphite with CNT in one‐step improves the performance of nanocomposites, and it offer an easy and viable alternative to obtain hybrid systems.

Carbon nanotube composites fabricated through filament winding process for battery preheating application

“…By incorporating CNTs‐GO into the PVA polymer, the cross‐section of CNTs yarn/CNTs‐GO PVA showed a distinct helical structure (Figure 2e), wherein CNTs bundles possessed more connections (Figure 2h) among the integrated three‐dimensional networks formed by hybrid CNTs and GO materials. It has been reported that the CNTs‐GO three‐dimensional network was conducive to load transfer efficiency 26 . Differently, the cross‐sectional view of carboxyl CNTs yarn/CNTs‐GO PVA showed a tight, uniform, smooth helical structure, with comparatively shorter CNTs bundles compared with those of CNTs yarn/PVA and CNTs yarn/CNTs‐GO PVA (Figure 2f).…”

“…It has been reported that the CNTs-GO three-dimensional network was conducive to load transfer efficiency. 26 Differently, the cross-sectional view of carboxyl CNTs yarn/CNTs-GO PVA showed a tight, uniform, smooth helical structure, with comparatively shorter CNTs bundles compared with those of CNTs yarn/ PVA and CNTs yarn/CNTs-GO PVA (Figure 2f). As shown in the high-magnification SEM image (Figure 2i), the CNTs bundles entangled together, besides, more CNTs bridges were observed between the two bundles owing to that the functional group within carboxyl CNTs yarn could entangle more CNTs nanomaterials.…”

The synergistic improvement in mechanical strength and toughness obtained in epoxy‐based composites incorporating with carbon nanotubes‐polymer hybrid construction

“…The storage modulus and loss factor are important parameters to characterize the viscoelastic behavior of a polymer‐based material 46,47 . As shown in Figure 7a, the storage modulus ( E ′) of CBH/EP composites gradually increases with increasing CBH loading content.…”

“…The storage modulus and loss factor are important parameters to characterize the viscoelastic behavior of a polymer-based material. 46,47 As shown in Figure 7a, the storage modulus (E 0 ) of CBH/EP composites gradually increases with increasing CBH loading content. The E 0 of the composite loaded with 3.5 wt% CBH increases to 3.64 GPa, which is 48.57% higher than that of the EP matrix (2.45 GPa).…”

“…[26][27][28][29][30] Different from these chemical and physical approaches, several 3-dimensional CNTs-micron substrate hybrid constructions with distinguished morphology have been designed and synthesized in recent years, providing a promising route to improve the CNTs dispersion in composites. [31][32][33] In our previous researches, by controlling critical synthesizing parameters, several CNTs-based hybrid constructions with different structures and morphology (diameter, length, density, and arrangement of CNTs array) have been designed and successfully synthesized through chemical vapor deposition (CVD) method, such as CNTs-alumina (Al 2 O 3 ), CNTs-glass fiber (GF), CNTs-porous spherical silica core(SiO 2 ), CNT-graphene nanoplatelets(GNPs), CNT-silicon carbide (SiC), CNTsilica coated reduced graphene oxide (SiO 2 @RGO). [34][35][36][37][38] He et al 35 reported a CNT-Al 2 O 3 hybrid reinforced epoxy composite, where a 56% enhancement in thermal conductivity was obtained in comparison with pure epoxy.…”