Structural, thermal, and surface wetting properties of epoxy resin/multiwalled carbon nanotubes composites

The structural, thermal and surface-wetting properties of epoxy resin/multiwalled carbon nanotubes (EP/MWCNTs) composites were studied by preparing nanocomposites by the physical mixing assisted by ultrasonication. The materials were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The contact angles of water droplets formed on the sample surfaces were measured to study their surface-wetting properties. FTIR showed the successful cross-linking of the EP matrix and good interaction between MWCNT and epoxy matrix in the nanocomposites. XRD attested that the incorporation of MWCNT in the EP did not influence the nature of the physical and chemical structures of the matrix polymer. Based on TGA results, the composites with chemically modified nanotubes were found to possess slightly higher thermostability than the analogous materials fabricated with the neat MWCNTs. Further, the EP/pristine MWCNT composites exhibited hydrophobic behavior while the EP/chemically modified MWCNT composites were comparatively hydrophilic which is attributed to the introduction of carboxyl groups during the chemical treatment of the nanotubes with strong acid.