Evolution Mechanism of Calcium Carbonate in Solution  

碳酸钙在溶液中的演化机理

作　　者：郭亚平[1,2,3] 唐海雄[2] 周玉[2] 贾德昌[2] 宁聪琴[3] 郭亚军[1] 

机构地区：[1]上海师范大学化学系,上海200234 [2]哈尔滨工业大学特种陶瓷研究所,哈尔滨150001 [3]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《Chinese Journal of Chemical Physics》2010年第6期731-737,746,共8页化学物理学报（英文）

摘　　要：Calcium carbonate was synthesized in a CaCl2/NaCO3 mixed solution by using ethylenediaminetetraacetic acid （EDTA） as an additive. The thermodynamics and kinetics analyses indicate that although the driving force of amorphous calcium carbonate （ACC） precipitation is always less than that of calcite and vaterite precipitation, the nucleation rate of ACC is greater than that of calcite and vaterite at the initial stage of the precipitation reaction. With the increasing incubation time, vaterite and calcite particles nucleate heterogeneously by using the as-formed particles as active sites. Scanning electron microscopy images indicate that the transformation mechanism of ACC and vaterite to calcite is the dissolution-recrystallisation reaction. The presence of EDTA not only improves the stabilities of ACC and vaterite, but also leads to forming enlongated, connected rhombohedral calcite crystals after incubation 7 days in solutions. The ACC and vaterite are stabler in air than in solutions at room temperature, although the dissolution-recrystallisation reaction occurs on the surface.

关 键 词：Calcium carbonate Dissolution-recrysatllisation reaction Phase transition 

分 类 号：O[理学]