The Adsorption and Dispersion Performance of Superplasticizers on Cement Particles

Abstract:

The adsorption of two superplasticizers, SNF and CE, on the cement particles were investigated. The results shown that, the adsorption of the superplasticizers could be described with Langmuir isothermal adsorption equation. The saturated adsorptive capacity of SNF and CE was 11.35 and 5.24 mg/g at 20°C, respectively. The adsorption of SNF was faster than that of CE. When the concentration of superplasticizer was 1.0 g/L, the ζ potential of the cement surface with SNF was -28.8 mV, while that with CE was -20.6 mV, indicating that the electrostatic repulsive force of SNF was stronger than that of CE. XPS spectrum disclosed the thickness of adsorption layer of CE and SNF on the cement surface was 9.8 and 1.5 nm, thus the steric repulsive force of CE was stronger. The dispersion experiment displayed that, the dispersion capacity of CE on the cement paste was much better than that of SNF.

• Periodical: Advanced Materials Research (Volumes 557-559)
• Pages: 887-892
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.557-559.887
• Online since: July 2012
• Authors: Da Feng Zheng, Xue Qing Qiu, Xiao Hong Sun, Yan Lin Qin, Hong Ming Lou, Dong Jie Yang
• Keywords: Adsorption, Dispersion Effect, Electrostatic Repulsive Force, Steric Repulsive Force, Superplasticizer

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