Studies on syneresis behavior of Xantlian/Cr(Ⅲ)hydrogels have been conducted at 70

80 and 90℃. The onset of syneresis appeared at a critical Cr(Ⅲ)density in a gel and the syneresis became serious when the Cr(Ⅲ) density increased.The process of syneresis can be described by means of apperant first-order reaction and the rate constant increased with increasing the temperature and the initial Cr(Ⅲ)concentration. The apparent activation energy was about 34.5 kcal/mol.Moreover

the syneresis did not depend on the concentration of monovalent salt (NaCl).