混合溶剂热法制备层状纳米结构碳酸钙

Preparation of layered nanostructured calcium carbonate by mixed solvo thermal method

针对目前层状纳米碳酸钙制备成本高、制备工艺复杂、有序度低等问题,以硝酸钠和碳酸钙为原料,以十二烷基磺酸钠为模板剂,采用混合溶剂热新方法,在醇水体系中成功制备了层状结构的纳米碳酸钙,探究了不同醇水比例和不同醇种类对碳酸钙产物的影响,并分析了合成机理.结果表明:制得的碳酸钙具有重复周期的层状纳米结构,长程有序,内部存在大量孔隙;碳酸钙样品组成为文石相和方解石相,改变醇水比例可以调控层状结构的有序度和产物中文石相和方解石相的比例;在乙醇/水体系中,当醇水比为1/2、1/1和2/1时,碳酸钙层状结构的重复周期分别为3.11 nm、3.09 nm和3.08 nm.在乙二醇/水体系中,当醇水比为1/2、1/1和2/1时,碳酸钙层状结构的重复周期分别为3.09 nm、3.13 nm和3.14 nm.

Aiming at the problems such as high cost,complicated preparation process and low degree of order in the research field of preparation of layered nanometer calcium carbonate at present.In this paper,sodium nitrate and calcium carbonate as raw materials,sodium dodecyl sulfate as a template,using a new hot solvent mixture in the alcohol-water system nanosized calcium carbonate layered structure was successfully prepared.The effects of different ratio of alcohol to water and different kinds of alcohol on calcium carbonate products were investigated,and the synthesis mechanism was analyzed.The results show that the prepared calcium carbonate has a repeating periodic layered nanostructures,long-range order,there are a large number of pores.Calcium carbonate samples are composed of aragonitic and calcitic phases.Changing the ratio of alcohol to water can control the orderliness of the layered structure and the ratio of aragonitic to calcite phases in the product.In the ethanol/water system,when the ratio of alcohol to water is 1/2,1/1 and 2/1,the repeated cycles of the layered structure of calcium carbonate are 3.11 nm,3.09 nm and 3.08 nm respectively.In the ethylene glycol/water system,when the ratio of alcohol to water is 1/2,1/1 and 2/1,the repeated cycles of the layered structure of calcium carbonate are 3.09 nm,3.13 nm and 3.14 nm respectively.