Title:
Multiscale Optimization of nCB-Cement Composites; Investigating the Effects of Chemical Surfactants on Dispersion, Electrical Conductivity, and Mechanical Performances
Author(s):
Soliman
Publication:
Web Session
Volume:
ws_F23_Soliman.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/29/2023
Abstract: Incorporating nanocarbon black (nCB) in cementitious materials turns them into multifunctional conductive composites. However, hydrophobic nature of nCB imposes challenges for effective dispersion within the cement composites. This study examines the impacts of various chemical surfactants on the dispersion of nCB-cement composites and consequently on electrical conductivity, mechanical, microstructure properties, and fracture properties. The study provides insights into the optimization of nCB to achieve a multifunctional cement composite with tailored properties at both microscale and macroscale. The results demonstrate that PNS and CMC display analogous effects on electrical conductivity evolution, whereas the PCE exhibits no significant influence on dispersion and electrical conductivity. However, high concentrations of PNS and CMC disrupt the volumetric wiring of nCB in cement composite. This occurrence can be ascribed to an increase in the volume fraction of PNS and CMC, leading to the disruption of conductive pathways or enlargement of interparticle distances between nCB conductive particles. Differently, enhanced compressive strength was observed at high PNS and combined PCE and CMC dispersants and diminished strength with CMC addition, while PCE demonstrated no significant impact on strength. Fracture properties improved with any surfactant utilization due to micropore filling and development of bridging forces between nCB and cement matrix.