聚天冬氨酸对CaCO_3的阻垢作用及其分子动力学模拟

Scale Inhibiting Effect and Molecular Dynamics Simulation of Polyaspartic Acid on CaCO_3

以氨水与马来酸酐为原料,热缩聚合成了聚天冬氨酸,表征结果显示其结构中含有α和β两种构型。通过静态阻垢实验测定了PASP对碳酸钙的阻垢性能,当PASP投加量为10mg/L时,阻垢率达到96.9%。采用分子动力学方法模拟计算了分子态和离子态PASP与方解石(104)和(110)晶面的相互作用,结果表明,离子态PASP-(110)晶面结合能、分子态PASP-(110)晶面结合能、离子态PASP-(104)晶面结合能、分子态PASP-(104)晶面结合能依次降低,说明PASP对方解石(110)晶面生长的抑制居于主导地位,与实验得到的结论相一致。

With ammonia and maleic anhydride as raw materials,polyaspartic acid（PASP）was synthesized by thermal polycondensation.The characterization results showed that PASP containedαandβtwo kinds of configuration.The scale inhibition of PASP on CaCO3 was determined through the static anti-scaling method.When the dosage of PASP was 10mg/L,the scale inhibition rate of CaCO3 was 96.9%.At the same time,the interactions of molecular and ionic PASP with（110）,（104）crystal surfaces of calcite were simulated by molecular dynamics（MD）.The results showed that the binding energy for polymers with two calcite crystal surface were decreased in the order of those for ionic PASP, molecular PASP with（110）crystal surface,and then ionic PASP,molecular PASP with（104）crystal surface,indicating that the combination of PASP with（110）crystal surface was more firmly than those with（104）crystal surface,so the scale-inhibition of PASP on the growth of（110）crystal surface was dominant, which was consistent with experimental conclusion.