Abstract: The crystalline a-Zr(HPO₄)₂·H₂O(a-ZrP) was prepared by three different methods - reflux, hydrothermal crystallization and HFprecipitation.The a-ZrPsample obtained by the HFprecipitation is the largest in size and the highest in sheet orderliness, while the sample prepared by the reflux method is the smallest in size and the lowest in sheet order1iness.The highest unit-layer crystallinity of a-ZrPcrystal was obtained by hydrothermal method.With the crystal size and the sheet orderliness of the crystal increasing, the dehydration temperature rises, and more alkylamine or amino-alcohol is needed to intercalate into a-ZrPfor its colloidization.The samples from HFprecipitation and reflux methods are easier to hydrolyze than the sample from hydrothermal method, but the hydrolysis percentage of all samples from three different methods are lower than 20%, even if the concentration of amine reaches the equivalent point.

Key words: Layered zirconium phosphate, Colloidization, Sheet orderliness