Carbon-based nanotube and graphene thermal stable materials generated via surface oxidation and chemical modification

Abstract

We have developed a facile approach to undertake chemical modifications of carbon nanotubes (CNT) and of graphite/graphene via oxidation and surface chemical modification to superhydrophobic nanomaterials. Chemical silane is functionalized to these oxide nanowires forms of carbon-oxygen-silicon chemical bonds via the liquid chemical-vapor-deposition (CVD) technique. After a correlation test of combinations of heating at a set temperature then measuring the surface water contact angle, these two types of materials have been generated showing both having very high thermally stable superhydrophobic nanomaterials. Both of modified CNT and graphene can maintain a superhydrophobic surface at extremely high temperatures, up to 550 and 600 °C, generated from graphene oxide (GO) and surface oxidized carbon nanotubes (CNTO), respectively. Over the critical switchable temperature, the surface switches from superhydrophobic to superhydrophilic immediately; it can be reversed to superhydrophobic by re-coating silane, thereby showing a reversible surface property. The superhydrophobic carbon nanomaterials can rapidly absorb oil either under water or from the surface water. Gaussian DFT calculations for the dissociation energies via different pathways confirm that this system is quite stable, consistent with the thermal test results.