高效减水剂在水泥颗粒表面的吸附

STUDY OF THE ADSORPTION OF PNS SUPERPLASTICIZER ON THE SURFACE OF THE CEMENT PARTICLES BY USING X-RAY FLUORESCENCE ANALYSIS

采用X射线荧光光谱方法(XRF)研究萘磺酸钠聚合物(PNS)高效减水剂在水泥颗粒表面的吸附。分析认为PNS中硫(S)元素含量是确定的,水化初期其它成分溶入水泥浆液相中的含S离子的变化情况也可以测定,且制定XRF标准曲线所需含S标准样品选取方便,因此S元素是合理的标定元素。从水泥浆体中分离出液相是XRF方法关键的步骤,测试数据表明过滤(抽滤)对XRF结果的误差影响不大。在此基础上,用XRF分析从水泥浆分离出的溶液中S元素的含量,进而计算PNS吸附结果。该结果与其他研究人员采用其它方法所得的研究结果相近。同时发现PNS高效减水剂在水泥颗粒表面吸附形态不是单分子层,而是其它形态。

The adsorption of polynaphthalene sulphonate superplasticizer (PNS) on the surface of cement particles is studied by using X-ray fluorescence (XRF) analysis. Results of the analysis indicate that the quantity of element S in PNS can be determined. The change of ions containing element S solved from other composites in the early stage of hydration can be tested too. It is convenient to prepare the standard sample containing S needed in determining the criterion XRF curve. So element S is believed to be a suitable demarcating element. One of the pivotal steps of the XRF method is how to separate the liquid from cement paste. The experiment data show that the effect of filtering on the errors of the XRF results is very light. Based on the above, the adsorption results of PNS superplasticizer can be determined by analyzing the quantity of element S in the liquid separated from cement paste by the XRF method. The results show that the adsorption result of PNS on the surface of cement particles obtained by this method is similar to that obtained by other methods. However the adsorption morphology of PNS on the surface of cement particles is not single molecular film. Further studies on the improving mechanism of superplasticizer and the adsorption morphology of superplasticizer on the cement particle surface as well are needed.