Alkali-activated materials with organics: A critical review

This paper represents a critical review on alkali-activated materials (AAM) containing organics with high homogeneity at nano-scale (<1 μm). Organics including organosilicons, surfactants, water-soluble polymers and epoxy resins can contribute to performance enhancement and tailorability of AAM based on their molecular characteristics. Hence, AAM with organics can generally possess improved characteristics between organic and inorganic components and may even exhibit emerging functional properties. According to the hybridisation modes between AAM and organics such as chemical bonding, physical adsorption, electrostatic attraction or phase crosslinking, these AAM with organics are categorised into four distinct types: organic-grafted, organic-adsorbed, phase-crosslinked and phase-separated AAM. In this paper, the hybridisation modes and reaction mechanisms of AAM with organics are summarised, for the first time, followed by a comprehensive discussion on the phase assemblage, microstructure, mechanical properties, durability and potential applications. Afterwards, the fundamental insights are gained and the remaining challenges for future research are identified and discussed.