ADSORPTION OF POLYACRYLAMIDE TO NA KAOLINITE - CORRELATION BETWEEN CLAY STRUCTURE AND SURFACE-PROPERTIES

Interactions between nonionic polyacrylamide and Na kaolinite in aqueous suspensions are discussed in terms of amide-hydroxyl H bonding. Correlations obtained by comparing the extent of adsorption of the polymer onto the clay mineral and onto synthetic aluminosilicates at different pH reveal the dominant effect of the surface density of 'free' hydroxyl groups acting as adsorbing sites on both adsorbent types. Most interesting is the opposing behavior of the basal and edge faces of the kaolinite with regard to the polymer/surface affinity.