Effect of gas phase oxidation on the structure and intertube adhesion force of a brush-like assembly of carbon nanotubes

Brush-like assemblies of carbon nanotubes produced using chemical vapor deposition were oxidized in stationary air in different oxidation conditions. Effects of oxidation on their structural properties were examined using microscopy and spectroscopy to evaluate changes in mass, CNT diameter, and the amount of disorder in samples. Separation force spectroscopy was also used, indicating a 50% increase in the adhesion force between CNTs in a mild oxidation regime, and indicating a sharp decrease in harsh oxidation conditions. By analyzing the relation between structural and chemical changes of CNT surfaces, we explored reasons for such trends in the forces interacting between CNTs.