Abstract: | Effect of structure of potassium poly(vinyl sulfate) and its homologs on the metachromatic behavior of methylene blue was investigated spectrophotometrically. The metachromatic behavior with addition of polyanions was followed by the changes in the molar extinction coefficient of the 664 nm band of methylene blue and in the wavelength of metachromatic band. Important factors for metachromasy were the number of anionic sites per polymer molecule, the degree of polymerization, and the flexibility of polymer chain. It was found that the amount of KCl or urea required to destroy the metachromasy was a useful measure for estimating the binding strength of methylene blue to polyanions. |