A Comprehensive Review of Nanocomposite Geopolymers: Mechanism, Properties, and Industrial Potential

Abstract

Geopolymers are inorganic polymers with amorphous or semi-crystalline structures formed by alkali activation of aluminosilicate-based materials. They are presented as a durable alternative to traditional Portland cement because of their low carbon footprint, high mechanical strength, and superior chemical and thermal resistance. However, their limited toughness and crack resistance restrict their application. To address these issues, nanocomposite geopolymers integrated with nanotechnology have been developed. The function of the nanoadditives used in the geopolymer matrix is twofold: (i) a nucleation effect that accelerates polycondensation and increases microstructure density; and (ii) a reinforcement effect that improves load transfer and limits microcrack propagation thanks to the high surface area and strong interface bonds. As a result, these mechanisms lead to significant improvements in compressive and flexural strength, toughness, and wear resistance. Additionally, nano additives enhance durability, particularly against freeze-thaw cycles, sulphate attack, and acid resistance, by reducing porosity. Functional additives, on the other hand, impart properties to geopolymers beyond their role as conventional building materials. For example, carbon nanotubes enhance electrical conductivity, electromagnetic wave attenuation, and piezoresistive sensor capabilities. Consequently, nanocomposite geopolymers are drawing attention not only in the construction industry but also in fields such as electronics, energy storage, catalysis, and advanced insulation. Overall, these materials show great promise due to their multifunctionality, strength, and durability. Future research should focus on adapting these materials to large-scale production processes, ensuring the even distribution of additives, and evaluating their long-term durability from environmental and economic perspectives