Viscosity behaviour of salt free aqueous solutions of sodium nickel and sodium copper copolyphosphate glasses

A number of samples of sodium nickel (NaNiPP) and sodium copper (NaCuPP) co polyphosphate glasses having Na:Ni/Cu ratio 9:1 and 8:2 were prepared along with control samples of sodium polyphosphate (NaPP) glass. Their number av erage molecular weights were determined by end group titration. Intrinsic v iscosities were determined in salt free aqueous solutions using the Fuoss e quation and correlated with molecular weights according to the Mark-Houwink relationship. Values of the constant a were found to decrease with increas ing amount of the counter cation (Ni2+/Cu2+) in the copolyphosphate glass. Fuoss equation parameters A, B and B/A and the molecular size (the root mea n square end-to-end distance), ((r) over bar (2))(1/2) were calculated for all the aforementioned glass samples. Values obtained for copolyphosphate g lasses were compared with those of control NaPP glasses.