Physicochemical characteristics of lanthanum hydroxide in hydroxyhydrogel and conventional gel form

Lanthanum hydroxide was prepared by wet interaction through precipitation as well as flash polycondensation, using lanthanum nitrate and ammonium hydroxide. The prepared materials were subjected to various physicochemical characterization. Rate constants and activation energies for dehydration, dehydroxylation and decarboxylation of synthesized materials were determined by dynamic and static thermogravimetry. Rate constants and activation energies were calculated with structural transformations, which were supported by XRD and FTIR analyses. The results showed that the physicochemical properties of the materials differ considerably with respect to the process parameters adopted during synthesis. (author)