Naslov
Microstructural Characteristics of Geopolymers Based on Alkali-Activated Fly Ash

Autori
Mužek, Mario Nikola ; Zelić, Jelica ; Jozić, Dražan

Izvornik
Chemical and Biochemical Engineering Quartely (0352-9568) 26 (2012), 2; 89-95

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
geopolymers; Class F fly ash; alkaline activations; XRD; FTIR; SEM/EDS

Sažetak
Aluminosilicate geopolymers with a high silica molar ratio have been prepared by mixing Croatian coal-ash (ASTM Class F) and sodium silicate solution (water glass, technical grade). The samples were cured at 85 °C for 8 h and 24 h in different experimental conditions. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDS) have been used to identify the new phases formed in geopolymeric binders, and to follow the progress of their formation. It was observed that the glassy component of fly ash used reacted with water glass. The main reaction product formed in the geopolymeric materials was amorphous alkali aluminosilicate gel that induces a shift in the T–O (T=Si or Al) asymmetric stretching band towards lower frequency (1074.58 cm^–1) in relation to the ones in the original fly ash. SEM/EDS detected a highly inhomogeneous glass-like matrix, constituted mainly of Na-Si-Al phases in a bulk region, together with unreacted spheres of fly ash particles.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA