Metakaolin-based geopolymers filled with volcanic fly ashes: FT-IR, thermal characterization, and antibacterial property

Abstract In countries where volcanic activity is widespread, fly ash (FA) formation can represent both a waste to be disposed of and resource inorganic substances that utilized. Among the technologies able incorporate FA, geopolymers (GP) or aluminosilicate amorphous materials are very suitable for this purpose. study, GP realized using metakaolin (MK), sodium hydroxide solution (NaOH 8 M), silicate (Na 2 SiO 3 ), FA as filler (20 wt% with respect MK content). The samples were cured at 25 40°C 24 h physicochemical, thermal, antibacterial properties material through integrity test, weight loss Fourier-transform infra-red spectroscopy (FT-IR), thermogravimetric analysis (TGA), Kirby-Bauer assay assessed. Integrity tests indirectly revealed stability macroscopic 3D networks curing led more stable GP. shift Si–O–T absorption band (from 1,090 cm −1 1,017–1,012 specimens without FA) in FT-IR spectra suggested occurrence geopolymerizazion reactions, while TGA study confirmed higher (with mass equal 7–13% 800°C under nitrogen atmosphere). Finally, antimicrobial shed light on ability synthesized treated have great effect against Escherichia coli Pseudomonas aeruginosa .