XPS测定减水剂吸附层厚度

通过XPS谱图和XPS信息深度的计算方法测定了减水剂在胶凝颗粒表面的吸附层厚度。结果显示，木质素磺酸盐减水剂（LS）、改性木质素磺酸盐减水剂（GCL1-T）、萘系减水剂（FDN）和氨基磺酸盐减水剂（ASP）在水泥颗粒表面的吸附层厚度分别为8.70、10.87、1.50、7.26 nm;GCL1-T和FDN在粉煤灰表面的吸附层厚度分别为6.76 nm和0.95 nm。此方法可较准确描述减水剂在胶凝颗粒表面吸附层厚度的相对大小。由测定结果可进一步推断，FDN的分散机理以静电斥力效应为主;而空间位阻效应在LS、GCL1-T和ASP的分散机理中不可忽略。

Measurement of adsorption layer thickness of water reducer by using XPS

The adsorption layer thickness of water reducer on the cement surface was measured through the XPS spectrum and the calculating method of XPS information depth.The results showed that the adsorption layer thicknesses of lignosulfonate(LS),modified lignosulfonate(GCL1-T),naphthalene sulfonate formaldehyde condensate(FDN) and aminosulfonate formaldehyde condensate(ASP) on the cement surface were respectively 8.70 nm,10.87 nm,1.50 nm and 7.26 nm,while those of GCL1-T and FDN on the fly ash surface were 6.76 nm and 0.95 nm.This method could describe the adsorption layer thickness of the water reducer exactly.From the results,it could be further concluded that the electric repulsive force was the main factor of the dispersion mechanism of FDN,while the steric repulsive force could not be neglected in the dispersion mechanisms of LS,GCL1-T and ASP.