Effects of Molarity and Storage Time of MWCNTs on the Properties of Cement Paste

Materials (Basel). 2022 Dec 17;15(24):9035. doi: 10.3390/ma15249035.

Abstract

Nowadays, nanomaterials in cement pastes are among the most important topics in the cement industry because they can be used for several applications. For this reason, this work presents a study about the influence of changing the molarity of dispersed multiple wall carbon nanotubes (MWCNTs) and varying the number of storage days on the mechanical properties of the cement paste. To achieve this objective, dispersions of 0.35% MWCNTs, varying the molarity of the surfactant as 10 mM, 20 mM, 40 mM, 60 mM, 80 mM, and 100 mM, were performed. The mixture of materials was developed using the sonication process; furthermore, materials were analyzed using UV-Vis, Z-potential, and Raman spectroscopy techniques. Materials with a molarity of 10 mM exhibited the best results, allowing them to also be stored for four weeks. Regarding the mechanical properties, an increase in the elastic modulus was observed when MWCNTs were included in the cement paste for all storage times. The elastic modulus and the maximum stress increased as the storage time increased.

Keywords: MWCNT; cement paste; dispersion; sonication energy; stability.

Grants and funding

La Facultad de Ciencias Exactas y Naturales at the Universidad Nacional de Colombia—Manizales for the financial support through the postgraduate student’s scholarship number 812 of 2018 and the project “Desarrollo de un sistema para la remoción de contaminantes en agua usando nanopartículas obtenidas con reactores de membrana.” Supported by the call “CONVOCATORIA DE PROGRAMAS CONECTANDO CONOCIMIENTO 2019”.