ADSORPTION OF ALKYLPHENOLS ONTO GREEN CLAY SURFACE IN THE PRESENCE OF NONIONIC SURFACTANT

Adsorption of alkylphenols onto green clay surface is studied by determining their adsorption isotherms separately than in the presence of various concentrations of the nonionic surfactant. When alone, alkylphenols are adsorbed with a mechanism close to that of surfactants. If the nonionic surfactant TX100 is added in the medium, the adsorbing properties are modified in a way that depends on the alkyl chain length. The longer the alkylchain length of alkylphenol molecule the weakest is the influence of TX100 surface aggregates on their adsorption behaviour. This behaviour, may be due in a part to the adsorbing properties of the alkylphenols that are able to self-aggregate at the clay/water interface and in a part to the limited swelling capacity of the TX100 micelles or surface micelles. Partition coefficients between aqueous solution and surface aggregates are determined and compared to that calculated for bulk micelles.