Characteristics of Nanosilica-Geopolymer Nanocomposites and Mixing Effect

Authors: H. Assaedi, F. U. A. Shaikh, I. M. Low

Abstract:

This paper presents the effects of mixing procedures on mechanical properties of flyash-based geopolymer matrices containing nanosilica (NS) at 0.5%, 1.0%, 2.0%, and 3.0% by weight. Comparison is made with conventional mechanical dry-mixing of NS with flyash and wet-mixing of NS in alkaline solutions. Physical and mechanical properties are investigated using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). Results show that generally the addition of NS particles enhanced the microstructure and improved flexural and compressive strengths of geopolymer nanocomposites. However, samples, prepared using dry-mixing approach, demonstrate better physical and mechanical properties comparing to wet-mixing samples.

Keywords: Geopolymer, mechanical properties, nanosilica.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1110780

References:

[1] P. Duxson, A. Fernández-Jiménez, J.L. Provis, G.C. Lukey, A. Palomo, J.S.J. Deventer, "Geopolymer technology: the current state of the art," J. Mater. Sci., vol. 42, no. 9, pp. 2917-33, 2007.
[2] J. Davidovits, "Geopolymers - Inorganic polymeric new materials," J Therm Anal, vol. 37, no. 8, pp. 1633-56, 1991.
[3] D. Pernica, P.N.B. Reis, J.A.M. Ferreira, P. Louda, "Effect of test conditions on the bending strength of a geopolymer- reinforced composite," J. Mater. Sci., vol. 45, no. 3, pp. 744-9, 2010.
[4] T. Phoo-ngernkham, Chindaprasirt P., Sata V., Hanjitsuwan S., Hatanaka S., "The effect of adding nano-SiO2 and nano-Al2O3 on properties of high calcium fly ash geopolymer cured at ambient temperature," Materials & Design, vol. 55, pp. 58-65, 2014.
[5] A. Nazari, J.G. Sanjayan, "Hybrid effects of alumina and silica nanoparticles on water absorption of geopolymers: Application of Taguchi approach," Measurement, vol. 60, pp. 240-6, 2015.
[6] M. Saafi, Andrew K., Tang P.L., McGhon D., Taylor S., Rahman M., et al., "Multifunctional properties of carbon nanotube/fly ash geopolymeric nanocomposites, "Constr. Build. Mater., vol. 49, pp. 46-55, 2013
[7] F. U. A. Shaikh, S. W. M. Supit, "Mechanical and durability properties of high volume fly ash (HVFA) concrete containing calcium carbonate (CaCO3) nanoparticles," Constr. Build. Mater., vol. 70, pp. 309-21, 2014.
[8] U. Rattanasak, P. Chindaprasirt, "Influence of NaOH solution on the synthesis of fly ash geopolymer," Miner Eng, vol. 22, pp. 1073-8, 2009.
[9] N.C. Tanw, A.v. Riessen, "Determining the Reactivity of a Fly Ash for Production of Geopolymer," J. Amer. Ceram. Soc., vol. 92, pp. 881-7, 2009.
[10] W. D. A. Rickard, R. Williams, J. Temuujin, A.v. Riessen, "Assessing the suitability of three Australian fly ashes as an aluminosilicate source for geopolymers in high temperature applications," Mater Sci Eng., vol. 528, no. 9, pp. 3390-7, 2011.