水溶液系中聚羧酸超塑化剂在C_3AH_6上的吸附过程研究

Adsorption Process of Polycarboxylate Superplasticizer onto C_3AH_6 in Aqueous Systems

采用紫外分光光度法测试水溶液体系中聚羧酸超塑化剂(polycarboxylate superplasticizer,简称PCE)在铝酸三钙(C3A)水化产物(C3AH6)上的吸附量,研究了聚羧酸初始浓度、分散时间、环境温度以及SO24-对吸附量的影响。采用准一级动力学模型、准二级动力学模型和颗粒内扩散模型进行动力学模拟,结果表明,C3AH6对PCE的吸附过程符合准二级动力学模型。利用Langmiur、Freundlich和Temkin等温吸附模型进行拟合,发现C3AH6对PCE的吸附规律符合Freundlich方程。红外光谱分析表明PCE在C3AH6上的吸附为化学吸附。

The adsorption of polycarboxylate superplasticizer （PCE） onto C3A hydration product was studied by UV spectrophotometer method. And, the influence factors such as initial adsorbate concentration, contact time, ambient temperature, sulfate ions and so on. The pseudo-first-order, pseudosecond-order and intraparticle diffusion models were used to describe the kinetic data and the kinetic constants were also determined. The results show that the adsorption kinetics data fitted the pseudosecond-order model. The Langmuir, Freundlich and Temkin equations were applied to describe the equilibrium isotherm and the isotherm constants were also evaluated. The law of the adsorption of PCE on C3AH6 fits the Freundich isotherm equation. FTIR reflects that the adsorption of PCE onto C3AH6 was chemical adsorption.