聚丙烯酸及马丙共聚物对硫酸钙垢阻垢机理的结晶动力学研究

The kinetic study of inhibition mechanism of PAA and AA/MA copolymer on CaSO_4·2H_2O scale forming

用加晶种于过饱和溶液中的方法测定了CaSO4 ·2H2 O晶体结晶生长的动力学过程 ,得到了不加阻垢剂及加阻垢剂两种条件下的结晶生长反应速率常数。结果表明 ,阻垢剂聚丙烯酸及马丙共聚物能明显地阻止溶液中CaSO4 在晶种表面的结晶生长 ,研究发现 ,阻垢的机理主要是阻垢剂对CaSO4 ·2H2 O晶种表面具有吸附作用 ,从而抑制了CaSO4 ·2H2 O的结晶生长 ,实验还证明了这种吸附作用符合Langmuir等温吸附特征 ,CaSO4 ·2H2 O晶体对阻垢剂的吸附属于单分子化学吸附 ,阻垢剂通过吸附于微晶表面的活性增长点 。

The growing dynamic process of CaSO 4·2H 2O crystal is determined by the method of adding crystal seed to the supersaturated solution. The speed constants of crystal growing are determined under the condition of no scale inhibitors or adding scale inhibitors. It is found that the growing of crystal CaSO 4·2H 2O in the solution is remarkably inhibited by PAA and MA/AA copolymer. The results indicates that the possible inhibition mechanism is the adsorption of inhibitors on the surfaces of crystal CaSO 4·2H 2O. The adsorption of inhibitors on the crystal surfaces accords with the characters of Langmuir model, which is a kind of single molecule layer sorption. The adsorption of inhibitor on the active site of crystal surfaces inhibits the growing of the crystal CaSO 4·2H 2O effectively.