Inter-particle forces arising from adsorbed bolaform surfactants in colloidal suspensions

Abstract

The effects of adsorbed bolaform surfactants, [HOOC(CH ₂ ) _n COOH], on the yield stress–pH behaviour of concentrated aqueous ZrO ₂ suspensions are reported. Both the bolaform concentration and its chain length, n, increase the yield stress. A ten-fold increase in the maximum yield stress, τ _ymax , is recorded for n10. The results are explained in terms of a particle bridging model. The increase in τ _ymax reaches a limit at the critical dimer concentration.