Structural and surface modifications of carbon nanotubes when submitted to high temperature annealing treatments

New findings on the influence of carbon surface curvature on energetics of benzene adsorption from aqueous solutions

“…As it has been pointed out [5] immersion calorimetry is a simple and very useful method applied for characterisation of solid surfaces (including nanotubes -see for example [6]) moreover, this technique can be successfully used for rapid characterisation of energetics of interactions between different liquids and solids [7] among them nanotubes. Castillejos et al [8] pointed out, that for better understanding of interactions between organics and nanotubes more research results are necessary since there are theoretical studies present however, there is only a limited number of experimental data. In their interesting studies Castillejos et al [8] also showed that curved surface of carbon nanotubes increases the adsorption strength of aromatic compounds in comparison to graphite.…”

Structural improvement of a bio-inspired 3D globular carbon foam by a continuously thermal treatment: A comprehensive study

“…As a result, the carbon structure has a high order in the formation of the graphitic layers and the healing process is completed. Contrary, several groups has been observed for CNTs a continuous reduction of the D/G ratio with increasing of the treatment temperature [26,28,29]. For the determination of the crystalline width L a , Knight and White developed the following empirical equation (3) [36].…”

“…The high temperature annealing of carbon structures especially of carbon nanotubes is a powerful tool to heal structural defects [25]. Several groups investigated the influence of the annealing on the morphology and improvement of properties of CNTs [26] or Graphene [27]. It was shown that with increasing temperature, the electrical resistance decreases and the oxidation temperature increases at the same time [22,26].…”

“…Several groups investigated the influence of the annealing on the morphology and improvement of properties of CNTs [26] or Graphene [27]. It was shown that with increasing temperature, the electrical resistance decreases and the oxidation temperature increases at the same time [22,26]. In addition, to high-temperature graphitization, first annealing processes with graphene could also be observed at a temperature of up to 600°C [27].…”

“…Furthermore, several groups showed that a temperature treatment of carbon structures results in a reorientation of the graphitic layers. Raman spectroscopy is an effective technique of measuring this structural change [25,26,28,29]. However, there are no comprehensive studies on the graphitization process and the influence of temperature.…”