L-赖氨酸接枝纳米碳酸钙的合成

Synthesis of L-lysine grafting nano-sized calcium carbonate particles

纳米CaCO3浆液中加入L-赖氨酸,在其表面引入羧基、氨基等活性基团实现表面改性,利用FTIR、XRD、SEM和TGA等手段对改性机理进行研究。结果表明：L-赖氨酸是以化学键合的形式接枝到纳米CaCO3表面,改性后的纳米CaCO3分散良好,晶面间距增大;L-赖氨酸接枝纳米CaCO3最佳工艺条件为：料浆CaCO3中质量分数为8%～10%,L-赖氨酸与纳米CaCO3质量比为0.1,改性温度70℃,时间70 min;优化工艺条件下,改性纳米CaCO3的活化度为46.3%。

By adding L-lysine amino acid in nano-sized CaCO3 slurry, it could introduce active groups such as carboxyl and amino on the surface of nano-sized CaCO3 particles to realize the surface modification. The mechanism of modification was studied by FTIR, XRD, SEM and TGA. Results indicate that L-lysine acid is grafted onto the surface of nano-sized CaCO3 particles in the form of chemical. The modified nano-sized CaCO3 particles is good in dispersion and increases interplanar distance. The optimum process conditions of L-lysine amino acid grafting nano-sized CaCO3 particles are that the mass fraction of CaCO3 in slurry is 8%～10%, the mass ratio of L-lysine to nano-sized CaCO3 particles is 0.1, modification temperature is 70 ℃, time is 70 min.Under the optimized condition, the activation degree of modified nano-sizde CaCO3 is 46.3%.