碳酸钙晶型的肉豆蔻酸调控研究

采用硝酸钙和碳酸钠的复分解反应制备碳酸钙,通过加入肉豆蔻酸对碳酸钙的晶体结构和表面性质进行调控,采用SEM、XRD、FT-IR、TG和XPS等方法研究了添加肉豆蔻酸对碳酸钙晶体结构的影响。结果表明,加入肉豆蔻酸之后,碳酸钙的晶体结构由球霰石变成方解石,形貌由球形变成了不规则的长方体形;碳酸钙的表面全部被活化,由亲水性变成疏水性,表面疏水后,碳酸钙的团聚程度明显降低;肉豆蔻酸的羧基阴离子和钙离子发生了化学结合反应,增强了碳酸钙结构的稳定性。总之,肉豆蔻酸的加入为碳酸钙的晶型调控与表面改性提供了一条简单的思路。

Crystal structure regulation of calcium carbonate by adding tetradecanoic acid

The calcium carbonate was prepared by double decomposition method.The crystal structure and surface properties of calcium carbonate were controlled by the addition of tetradecanoic acid.The effects on the crystal structure of calcium carbonate were studied by SEM,XRD,FT-IR,TG and XPS after the addition of tetradecanoic acid.Results showed that the crystal structure of calcium carbonate changed from vaterite to calcite after the addition of tetradecanoic acid,and the morphology changed from spherical to irregular cubic shape;the surface of calcium carbonate were wholly activated and hydrophobic,which reduced the degree of agglomeration of calcium carbonate.The interaction between tetradecanoic acid anion and calcium ion form a covalent binding which improves the stability of calcium carbonate particles.In conclusion,the addition of tetradecanoic acid can provide a method for crystal structure and surface modification of calcium carbonate.