Abstract
Solid state 29Si MAS NMR is a versatile spectroscopic technique to study anisotropic interactions of Si in geopolymeric cement systems. This article is concerned with the analysis of structural information and mechanism for evolution of tailored geopolymeric precursor powder originated after mechanical co-grinding of fly ash, NaOH and amorphous tricalcium phosphate. The solid state 29Si MAS NMR of geopolymeric precursor material shows distinguishable chemical shifts. Results indicated that developed geopolymeric precursor contain Si/Al tetrahedral network in which SiQ4(3-4Al) dominated among Q0, Q1 and Q2. The evolution of green phosphatic geopolymer cement material takes place after addition of water to developed precursor material. Results also provide an insight about -Si-O-Si- interactions in geopolymer precursor formation, due to reorganization and structural disordering, as a noteworthy greener solid state mechanism. Another eminent finding of this study is the occurrence of significant change in chemical shift values caused by grinding. These shifts are accompanied by incorporation of Al in Si-O-Si linkages and 3D crosslinking into the matrix in geopolymeric precursor material itself, leading to formation of transient Si/Al containing species following solid state mechanism.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call