Adsorption behaviour of polyelectrolytes on calcium fluoride - Part I: influence of the pH and the ionic strength on the adsorption isotherms

The adsorption behaviour of weak polyelectrolytes onto CaF2 crystals has be en investigated to support the research on the mechanism of growth retardat ion. Adsorption isotherms and surface concentration plateau values of three kinds of poly(phosphino)acrylate, a polyacrylate and a polymaleate were de termined at different pH values in pure water and at a higher ionic strengt h. It was found that the surface concentration plateau values decrease with decreasing pH. The addition of an indifferent salt makes the polyelectroly tes more flexible due to partial screening of the polyelectrolyte charge. ( C) 1999 Elsevier Science B.V. All rights reserved.