硫酸盐影响聚羧酸减水剂分散性的作用机理

发布时间：2018-03-16 04:28

本文选题：聚羧酸减水剂　切入点：硫酸盐　出处：《同济大学学报(自然科学版)》2015年02期 　论文类型：期刊论文

【摘要】：系统研究了硫酸盐对聚羧酸减水剂吸附-分散性能的影响及其作用机理.通过净浆流动度试验及Marsh时间试验研究了硫酸盐种类及掺量对聚羧酸减水剂分散性能的影响,并通过zeta电位、平衡吸附量及絮凝结构形貌等微观测试手段对硫酸盐影响聚羧酸减水剂分散性的作用机理进行分析.结果表明:随着硫酸根溶出率及溶出速率的增加,硫酸根离子与聚羧酸减水剂间的竞争吸附作用增强;硫酸根离子破坏浆液双电层,促使zeta电位绝对值下降,从而削弱水泥颗粒表面的静电斥力作用,导致水泥浆体絮凝结构数量及强度增大,相同剪切速率对浆体中的絮凝结构破坏程度下降,浆体分散性及流变性下降.
[Abstract]:The effects of sulphate on the adsorption-dispersion properties of polycarboxylic acid superplasticizer and its mechanism were systematically studied. The effects of kinds of sulfate and the amount of sulphate on the dispersion of polycarboxylic acid water reducer were studied by slurry fluidity test and Marsh time test. The mechanism of sulfate affecting the dispersion of polycarboxylic acid superplasticizer was analyzed by means of zeta potential, equilibrium adsorption capacity and flocculation structure and morphology. The results showed that with the increase of sulfate dissolution rate and dissolution rate, the effect of sulfate on the dispersion of polycarboxylic acid superplasticizer was studied. The competitive adsorption between sulfate ion and polycarboxylic acid superplasticizer is enhanced, the sulfate ion destroys the double electric layer of slurry, and the absolute value of zeta potential decreases, which weakens the electrostatic repulsion force on the surface of cement particle. The number and strength of flocculation structure of cement paste increased, the destruction degree of flocculating structure in slurry decreased at the same shear rate, and the dispersion and rheology of slurry decreased.
【作者单位】：同济大学材料科学与工程学院;同济大学先进土木工程材料教育部重点实验室;
【基金】：国家自然科学基金(51378391) “十二五”国家科技支撑计划(2011BAE27B04)
【分类号】：TU528.042.2

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