Investigation on effect of nanosilica dispersion on the properties and microstructures of fly ash-based geopolymer composite

Nanosilica-geopolymer composites with different dispersion levels of nanoparticles were investigated on the physical properties and gel properties. The results indicated that compared with the nanosilica-geopolymer composites without ultrasonic dispersion, the 20 and 120 min of sonication brought 3.88% and 13.59% of additional strength enhancement, respectively. For the micromechanical properties of N-A-S-H gel, the better dispersed samples exhibited higher elastic modulus. In comparison to the reference sample, the elastic modulus was increased by 15.18% and 29.93% respectively for samples with 20 and 120 min of sonication. The better dispersed nanoparticles exhibited smaller sizes and increased the physical filling effect which could result in densified microstructures, better bonding behaviors and the both improved micro and macro mechanical properties. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Different dispersion levels of nanoparticles in nanosilica-geopolymer composites were studied for their physical and gel properties. Ultrasonic dispersion for 20 and 120 minutes led to additional strength enhancement and increased elastic modulus of the N-A-S-H gel. Better dispersed nanoparticles resulted in densified microstructures, improved bonding behaviors, and enhanced micro and macro mechanical properties.