Journal of the Chinese Institute of Chemical Engineers, Vol.29, No.2, 129-137, 1998
An examination on the adsorption kinetics of 1-decanol at air-water interface
The adsorption kinetics of 1-decanol was investigated by measuring the equilibrium and dynamic surface tension profiles by Lin et al. (1995). From the relaxation of surface tension for the adsorption onto a clean air-water interface and the desorption out of a compressed interface, the diffusivity and the kinetic rate constants of 1-decanol were evaluated. in this work, the adsorption kinetics for 1-decanol is examined theoretically. Using the equilibrium data of surface tension, diffusivity and the generalized Frumkin adsorption model, the relaxations of surface tension of the adsorption and desorption processes are simulated. Novel regions, where the adsorption onto a clean interface is of diffusion-control and the desorption out of a compressed interface is mixed-controlled, at different compression ratios are identified for 1-decanol. This is resulted from the presence of cohesive intermolecular forces between the decanol molecules adsorbed at the air-water interface. The data of kinetic rate constants evaluated by Lin et al. are also compared with the novel regions. Decanol is verified theoretically that the adsorption onto a clean interface is diffusion-controlled and the desorption out of a compressed interface is of diffusive-kinetic control.
Keywords:SURFACTANTS