SALT EFFECT ON SURFACE MODIFICATION OF SILICA BY INTERPOLYELECTROLYTECOMPLEXES

The effect of a low-molecular-mass salt on the properties of interpoly electrolyte complexes formed as a result of interactions between poly( diallydimethylammonium chloride) and copolymers of maleic acid with pr opylene or alpha-methylstyrene in their salt containing non-stoichiome tric mixtures has been studied. Properties of such interpolyelectrolyt e complexes were found to be determined by the chemical nature of the polyelectrolytes and by the salt concentration. The effect of salt on the surface modification of silica particles via their interactions wi th interpolyelectrolyte complexes has been examined. Two different way s of the surface modification of silica particles were used: (i) silic a particles were contacted with previously prepared interpolyelectroly te complexes and (ii) silica particles were contacted with cationic po lyelectrolyte at first and then anionic polyelectrolyte was added. The efficiency of the surface modification was shown to be also dependent on the salt concentration and the chemical nature of polyelectrolytes . Turbidimetry, quasi-elastic light scattering, laser microelectrophor esis, and polyelectrolyte titration were used to characterize studied systems.