Effect of organosilicone on the reaction process of functionalized geopolymers

Abstract

We have recently synthesized a novel alkylated-geopolymer (AGP) with superior water and corrosion resistance based on organic-inorganic hybridization technique, which is desirable for various applications in building engineering. In this work, the impact of sodium methyl siliconate (SMS), which serves as a vital organic component, on the reaction process of metakaolin-based geopolymers was investigated. The research focused on the underlying mechanisms by evaluating the variation of properties including the apparent viscosity, reaction heat, mechanical strength, chemical composition, and microstructure. The results reveal that initial AGP pastes cured for 1 d exhibit higher strength and reactivity compared to the OGP paste. Organosilicon monomers demonstrate greater competitiveness than [Al(OH)4] monomers in forming initial alkylated sodium aluminosilicate hydrate (A-NASH) gels, thereby enhancing the early-age reaction of the AGP paste. In contrast, the strength and polymerization degree of final AGP pastes cured for over 7 d are relatively lower, indicating educed susceptibility of A-NASH gels to rearrangement and reorganization, which correlates with the number of the binding site of the [H3C–Si(OH)3] unit. These findings provide valuable insights for synthesizing organic-inorganic hybrids and offer guidance for the practical application of AGP materials in engineering contexts.