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.