INFLUENCE OF PH ON THE FORMATION OF POLYPHOSPHATE COACERVATES

The coacervation of polyphosphates usually takes place at very low pH value. We show that, in the system Na2O-CaO - P2O5, the decrease of pH is due the hydrolysis of the terminal P-OH groups and that it is a consequence of the coacervation. So a very low pH is not necessary to obtain a coacervate and it is possible to form coacervates in non-acid media (even basic). The same results are obtained with other precursor systems of polyphosphate coacervates. These results may be interesting for the achievement of coacervates as industrial glasses precursors.