Effect of polyelectrolytes on the kinetics of ionic reactions: III. Hydrolysis of pyrophosphate in poly-(ethyleneimine) solutions

Abstract

The effect of the weak polyelectrolyte poly(ethyleneimine) on the rate of hydrolysis of pyrophosphate has been studied as a function of pH at 70°C. Inhibition by the macroions was observed at pH ⩾ 2, the inhibition becomes stronger as pH increases. At pH > 7 the hydrolysis in the presence of polyions becomes undetectable. Addition of NaCl to the solutions reduces the inhibitory effect of the polyelectrolyte. Electrostatic interactions between macroions and substrate ions cause the observed inhibition, therefore this is another manifestation of the polyelectrolyte effect due to the large charge density on the polycations.