The article aims to provide a comprehensive understanding of how alkali-activated aluminosilicate materials (AAMs) form, focussing on both chemical reactions and associated rheological changes during geopolymerization. These emerging inorganic polymeric materials are gaining prominence in the construction industry as sustainable alternatives to Ordinary Portland Cement (OPC), offering reduced energy consumption and significantly lower carbon emissions. Geopolymerization, the process of alkali activation of aluminosilicate precursors, forms a hardened three-dimensional network through a series of complex chemical and physical transformations. While previous research has extensively studied the chemical mechanisms and various influencing parameters to tailor material properties, relatively little attention has been given to linking chemical mechanisms with concurrent rheological changes. This relationship is critical because chemical reactions directly influence rheological behavior, affecting workability, setting, and the final performance of AAMs. Understanding this linkage is essential for optimizing their practical applications. The present work bridges the gap by tracing intermolecular forces, reaction kinetics, and rheological behavior throughout the geopolymerization process. It highlights how precursor composition, alkali concentration, and temperature influence the rheology of the matrix, thereby affecting the final material performance. The insights from this study enable engineers and materials scientists to better understand the fundamental mechanisms guiding the development of alkali-activated materials, ultimately supporting the design of novel materials with enhanced mechanical properties, durability, and a broader range of construction applications. The article also highlights emerging machine-learning strategies that relate chemical and rheological parameters with material performance and accelerate the design of AAMs. Key factors governing geopolymerization and their relationship with chemical evolution, rheological behavior, and the resulting performance of alkali-activated aluminosilicate materials.
MXenes are a class of two-dimensional materials whose tunable surface chemistry renders them promising for a wide range of applications, including catalysis and energy storage. Their surface chemistry is initially established during synthesis from their parent MAX phases through selective etching and serves as a key tunable parameter that governs MXenes’ functional properties and behavior. However, MXene surfaces are not static. Beyond synthesis, their surface terminations can be deliberately engineered, and, importantly, continue to evolve dynamically under chemical, electrochemical, and thermal operating conditions. Such transformations include termination removal, substitution, reconstruction, and protonation. Consequently, MXenes’ performance is governed by the in operando evolution of surface chemistry, rather than solely by the initial terminations introduced during synthesis or post-synthesis modifications. Embracing this dynamic paradigm reframes MXene surface chemistry from a synthetic descriptor to a design variable, opening opportunities to engineer reaction pathways, stabilize transient active states, and couple structure with function in real time. By conceptualizing MXene surfaces as dynamic interfaces, this article highlights how surface chemistry transforms under working conditions and how this evolution can be rationally harnessed to optimize performance in various applications, including catalysis and energy storage.
