聚羧酸减水剂空间位阻表征方法探讨

Study on Characterization Methods of Steric Hindrance of Polycarboxylate-type Superplasticizers

聚羧酸高效减水剂的作用机理为静电斥力和空间位阻效应,其中以空间位阻效应为主。根据高聚物在固/液界面吸附行为,探讨以吸附层厚度和吸附构象作为主要参数来表征和研究聚羧酸减水剂吸附在水泥颗粒表面引起的空间位阻效应;讨论了X射线光电子能谱(XPS)、俄歇电子能谱(AES)、原子力显微镜(AFM)、光子相关光谱(PCS)、单分子力谱(SMFS)、流体力学、椭圆偏振、Monte Carlo模拟等方法在表征减水剂空间位阻的可行性、相关研究成果及其局限性,展望了聚羧酸减水剂空间位阻效应的研究前景。

The mechanism of polycarboxylate-type superplasticizers can be explained by electrostatic repulsion and steric hindrance,but the latter gains more popularity.Based on the adsorption behavior of polymer on the solid/liquid interface,the thickness of adsorption layer and adsorption conformation are taken as parameters to study the steric hindrance caused by the polycarboxylate-type superplasticizers adsorbed on the surface of the cement particles.The paper discussed the feasibility and drawbacks of the methods of X-ray photoelectron spectroscopy（XPS）,auger electron spectroscopy（AES）,atomic force microscope（AFM）,photon correlation spectroscopy（PCS）,single-molecule force spectroscopy（SMFS）,hydromechanics,ellipsometry and Monte Carlo simulation in the characterization of the steric hindrance,and makes an outlook to the research prospect of polycarboxylate-type superplasticizers.