Tuning muscovite into geopolymer product through thermal–mechanochemical activation

Enhancing the reactivity of highly crystalline T–O–T clays such as muscovite remains a bottleneck for alkali-activated binders. This work compares thermal treatment (T), mechanochemical activation (MCA), and their sequences—calcination followed by MCA (T–MCA) and MCA followed by calcination (MCA–T)—to establish how activation order governs structure–reactivity–performance. Integrated multi-scale characterization, supported by molecular dynamics, shows that T induces dehydroxylation with limited framework disruption, whereas MCA generates defects and particle refinement without removing long-range order. In contrast, T–MCA produces extensive loss of periodicity and a higher density of accessible reactive sites, accelerates early dissolution–polycondensation, and yields mixed N-A-S-H/K-A-S-H gels with superior early strength. MCA–T promotes the persistence of defects via layer collapse and local reorganization, thereby slowing reaction kinetics and yielding Na-dominated gels with limited strength. These findings position T–MCA as a practical route to convert muscovite into high-performance alkali-activated binders and geopolymers—particularly where conventional ashes or slags are scarce but muscovite resources are abundant—and provide design guidance linking layered-silicate destabilization to reaction kinetics, gel assemblage, and mechanical performance. © 2026 Elsevier Ltd.