Polyelectrolyte containing dihydronicotinamide. II. Interaction of polymer and substrate

Abstract Reduction of crystal violet (CV) by poly(sodium styrene‐ p ,‐sulfonate) containing dihydronicotinamide (NAH) groups (PNAH) was compared with that by poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate) containing NAH groups (PNAH‐AMPS) in aqueous media. PNAH reduced CV far more effectively than PNAH‐AMPS, suggesting the presence of both hydrophobic and electrostatic interaction between PNAH and CV. An obvious color change was observed on addition of CV to the polyelectrolyte solutions, which was largely affected by the kind of polymers and the experimental conditions such as ionic strength and medium composition. These results imply that the location of CV within the macromolecular domain is an important factor for the polyelectrolyte‐induced metachromasy. Some correlations of the metachromatic behaviors of CV with the reduction were also discussed.