Investigation of the Structure of a Cement Composite Modified by Hydrothermal SiO2 Nanoparticles and MCNT Nanoparticles by the X-Ray Phase Analysis Method.

Autor: Polonina, E. N., Potapov, V. V., Zhdanok, S. A., Leonovich, S. N.
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Zdroj: Journal of Engineering Physics & Thermophysics; Jan2023, Vol. 96 Issue 1, p215-223, 9p
Abstrakt: The x-ray phase analysis method has been used to study the effects of small doses of hydrothermal SiO2 nanoparticles and nanoparticles of multiwalled carbon nanotubes (MCNTs) on the structure of a Portland cement composite separately and in a combination at the age from 4 h to 28 days. It has been established that clinker minerals and Portlandite components do not differ significantly in nanomodified specimens compared to control specimens, which agrees with the thermogravimetrical data for the ages of 1 and 28 days. In the region of the angles 2θ = 5–12 degrees, structural differences were identified for the CSH gel in the nanomodified specimens: at the age of 1 day (24 h), there were CSH peaks (I) in the diffraction patterns of the modified specimens with Basel distances of 12.44–12.54 Å between the layers. At the age of 28 days, relatively higher peaks of a tobermorite-like structure were identified with a Basel distance reaching a maximum value of 14.54 Å in a specimen modified by a combination of SiO2 and MCNT nanoparticles. The increase in the Basel distances corresponds to a reduction in the values of the Ca/Si ratio and an improvement in the ordering of the CSH-gel structure and agrees with the IR-spectroscopy data having shown the higher degree of polymerization of silicon–oxygen tetrahedrons in nanomodified specimens. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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