A study of the composition of polyacrylamide-polyaluminum chloride polymer-colloid complexes

The behavior of aqueous solutions of polymer-colloid complexes based on polyacrylamide (M ～ 5.2 × 10⁵) and colloid particles of polyaluminum chloride depending on the initial component ratio and the concentration of a low-molecular-mass electrolyte (NaCl) was studied by means of viscometry and turbidimetry. It was suggested that the composition of polymer-colloid complexes, ? (the number of colloid particles attached to one macromolecule), depends on the component ratio. At ? > 1, the polymer-colloid complexes take on the polyelectrolyte properties, namely, repulsion in the case of overlap of the diffuse layers of counterions of colloid particles bound to the polymer chain leads to unfolding of macromolecular coils. Correspondingly, as the concentration of a low-molecular-mass salt increases, the coil size diminishes and the solubility of the complex drops. At ? = 1, the concentration of low-molecular-mass salt has no effect on the solubility of the complex and the viscosity of its solution.