Interaction between polyelectrolytes and heteropolar precipitates

Abstract
The interactions of some polyelectrolytes (anionic–gum arabic, agar; ampholytic–gelatin) with silver bromide sol in statu nascendi were studied. It was found that there are analogous phenomena to those encountered with usual hydrophobic sols. The polyelectrolyte effects on hydrophobic systems were treated in a manner usual for simple electrolytes. The appearance of the typical coagulation curves with maximum is used for the characterization of various systems: hydrophobic colloid–polyelectrolyte–electrolyte. Depending upon the position of the system on “stabilizing” or “sensitizing” side of this maximum (sometimes of minimum), there is a very pronounced difference of the polyelectrolyte action on the coagulation value of simple electrolyte. Thus, on the “stabilizing” side, the “reverse” antagonism was found, which is explained as a result of the dominating polyelectrolyte adsorption effect.