Effect of ultrasonic treatment on ripening of titanium oxalate salt from solution

Titanium oxalate was precipitated by the addition of TiO(NO3)(2) solution t o an ethanol solution of oxalic acid and then ripened in the mother solutio n with/without ultrasound at various temperatures. The influence of various factors such as reaction temperature and ripening time, as well as the eff ect of ultrasonic treatment in the solution, was investigated. During the r ipening reaction of the titanium oxalate, a new crystalline phase was found . The chemical formula and the crystal system of the new phase were as foll ows: (1) Chemical formula-Ti2O2(C2O4)(OH)(2)H2O, (2) Crystal system-orthorh ombic with lattice constants of a = 1.0503 nm, b = 1.5509 nm, and c = 0.970 0 nm. The treatment of ultrasound during the ripening reaction accelerated the dissolution rate of the initial precipitated particles, so that the for mation of the crystalline phase was hastened. (C) 1999 Kluwer Academic Publ ishers.