THE ADSORPTION OF POLYSTYRENE SULFONATE AND ETHOXYLATED NONIONIC SURFACTANTS AT CARBON BLACK-WATER INTERFACE

The adsorption of a series of sodium polystyrene sulfonates with a nar row distribution of molecular weight and ethoxylated non-ionic surfact ants (NP-12, NP-40, NP-100 and C(16)E(20)) was investigated at carbon black-water intel face. Adsorption isotherms of the Langmuir type were obtained for all the samples with negative adsorption free energies. The dependence of maximum of adsorption on molecular weight for PSSNa was used to obtain information on the macromolecular conformation at t he interface; surface geometry effects on adsorption conformation were analyzed using a simplified fractal approach. PSSNa does not adopt a fiat conformation at the interface. Non-ionic surfactants (NP-12, NP-4 0, NP-100 and C(16)E(20)) are adsorbed at the interface with the EO ch ains in a coil conformation.