Liquid-phase adsorption of tetracene and phenanthrene on a single-walled carbon nanotube (SWCNT) was examined. Tetracene adsorption was more than six times greater than that of phenanthrene. X-ray photoelectron spectroscopic examination clearly showed that tetracene and phenanthrene molecules efficiently coated the SWCNT external surfaces. The remarkable difference between the adsorption amounts of tetracene and phenanthrene was caused by the nanoscale curvature effect of the tube surface, resulting in a difference in the amount of contact between the molecule and the tube surface. The adsorption of tetracene and phenanthrene caused a significant higher frequency shift in the radial breathing mode (RBM) of the Raman band of the SWCNT, indicating an intensive pi-pi interaction between these polycyclic aromatic hydrocarbons and the external SWCNT surface.

Phenanthrene was adsorbed from ethanol solution to the surface of single wall carbon nanotubes, which were previously physically and chemically characterized. Different anionic surfactants were added in the solutions to enhance the phenanthrene solubility and apparently have also improved the dispersion of two respective nanotube samples used. Adsorbed amount was determined through the concentration difference measured by UV-visible spectrophotometry. Results suggest that adsorption of phenanthrene is extremely improved in the case of nanotube purified with higher quality. These findings were confirmed by X-ray photoelectron spectroscopy. The influence of the surfactant on the adsorption kinetics of phenanthrene is suggested to be significant as well.

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The adsorption of phenol from dilute aqueous solutions by seven activated carbons and one non-porous carbon black is reported. It is confirmed that the equilibrium can be described by a modified Dubinin-Radushkevich-Kaganer equation, with exponent n = 4 and Es = (1.03 ± 0.18)Eo. At low equilibrium concentrations, phenol and its derivatives are adsorbed as monolayers by both non-porous and porous carbons. However, water is preferentially adsorbed on the oxygen-containing surface complexes, which reduces the area available to phenol and its derivatives by 71 m2 per mmol of surface oxygen.