The adsorption kinetics and thermodynamics of cationic surfactants on graphite oxide

The adsorption isotherms and structural evolution of alkyl quaternary ammonium bromide (C TAB) on graphite oxide (GO) were measured by means of an elemental analyzer, X-ray diffraction and Fourier transform infrared spectroscopy. In order to interpret the adsorption mechanism of surfactants onto GO, the adsorption kinetics and thermodynamics were further investigated. It was found that GO is a relatively efficient adsorbent within a wide range of temperatures (297–353 K), and the C TAB was intercalated and then agglomerated into the interlayer spacing of GO via ionic bonding and hydrophobic bonding. The saturation amount of alkyl ammonium adsorbed on GO was decreased with the rise in temperature, and the experimental data fitted well into the modified Langmuir (Langmuir-Freundlich) equation. In addition, the negative values of Δ and Δ showed that the adsorption process of C TAB onto the GO was spontaneous and exothermic.