STUDY ON THE SURFACE-ACTIVITY OF DISPERSANTS AND THEIR ADSORPTION BEHAVIOR ON CLASS-G CEMENTS

Surface-activity of polyelectrolytes in water may be characterized by a decrease in surface tension with concentration and formation of mice lle at a particular concentration, known as critical micelle concentra tion (CMC). The critical micelle concentration of aqueous solution of dispersants has been determined by surface tension and viscosity measu rements at 30 degrees C. CMC is observed at 0.2% and 0.15% concentrati ons for dispersants, DISP-1 and DISP-2 respectively. Adsorption behavi our of dispersants has been studied on class 'G' cements. It is observ ed that the magnitude of surface adsorption increases with increase in dispersant concentration. The influence on cement slurry parameters i s also investigated with the aim to evaluate their effectiveness and t o determine their optimum concentrations with respect to critical velo city and fluid - loss parameters. Certain relationship exists between dispersant adsorption on cement particles, critical velocity and fluid - loss parameters of cement slurry.