膦酰基羧酸调聚物对硫酸钙的阻垢机理

The Antiscaling Mechanism of Phosphono Carboxylic Acid Telomers on CaSO_4

静态阻垢法试验表明,膦酰基羧酸聚合物(POCA)对硫酸钙垢沉积具有优异的抑制作用,当加药量为5mg/L时阻垢率达到100%。投加POCA前后硫酸钙表观形貌的变化的扫描电镜分析证实,POCA对垢晶体具有强烈的扭曲畸变作用。随着加药浓度的提高,POCA对晶面的畸变作用增强。采用分子动力学(MD)模拟,计算了POCA与硫酸钙晶体的最主要生长面(020)和主要生长面(010)晶面的相互作用,对体系各种相互作用的分析表明,POCA在与硫酸钙晶体结合过程中其结合能远大于常规吸附能,使其容易占据晶体的活性生长点而使晶格发生畸变;POCA对(020)晶面的作用比对(010)晶面的强;超分子体系的作用能主要由库仑作用提供。

The results of static scale-inhibiting tests showed phosphono carboxylic acid telomer （POCA） has excellent inhibition effect on CaSO4 scale sediment, and the scale-inhibiting efficiency was 100% when the concentration of POCA was 5mg/L. The changes of configuration CaSO4 induced by POCA had been studied by scanning eiectron microscope （SEM）, it was confirmed that POCA caused strong twist and distortion of calcium sulphate. The higher the concentration of POCA, the stronger the distortion of POCA on crystal surfaces was. At the same time, the interactions between POCA and the most important growth surface （020） and main surface （010） of CaSO4 crystal had been simulated by molecular dynamics （MD）. The analysis of various interactions of all systems indicated that binding energy between POCA and CaSO4 crystal is far larger than normal absorbing energy during POCA combining with CaSO4 crystal surfaces, so that POCA was easily locked in living dot of crystal to cause the aberration of lattice. The interaction was stronger between POCA and （020） surface of CaSO4crystal than that between POCA and （010） surface of CaSO4 crystal. The interacting energies between POCA and crystal surfaces were mainly provided by coulomb interaction.