The adsorption kinetics of 1-N-l-tryptophan–glycerol-ether surfactants at the air–liquid interface: effect of surfactant concentration and alkyl chain length

Dynamic surface tension of aqueous alkaline solutions of 1-N-l-tryptophan–glycerol-ether surfactants, Cn-TEG, below its critical micelle concentration has been measured as a function of the surfactant concentration and over a temperature range of 19.7–31.5 °C. The static tension of the alkyl tryptophan–glycerol-ether surfactants with n=9–11 is analyzed in terms of the combined Frumkin–Davies isotherm. By using this state equation the adsorption kinetics of these surfactants can be interpreted as a diffusion-controlled process.