Geopolymer-based composite and hybrid materials: The synergistic interaction between components

In recent years, there has been a growing drive toward developing innovative materials capable of meeting the demands of sustainability, durability, and high performance across multiple application sectors. In this context, geopolymer-based composites and hybrid materials have emerged as highly promising candidates, leveraging the synergistic interactions between inorganic geopolymer matrices and reinforcing phases of diverse nature, ranging from fibers and nanoparticles to organic polymers and industrial waste derivatives. These combinations enable the fine-tuning of mechanical, thermal, and chemical properties, creating materials tailored for specific functional and structural roles. Recent research on geopolymer-based composites has shown that the integration of reinforcements not only improves crack resistance and toughness but also expands the range of applications beyond traditional construction. Moreover, the development of true hybrid systems, especially through coreticulation or cross-linking with organic polymers, has paved the way for materials with enhanced interfacial bonding, multifunctionality, and superior performance. Despite significant progress in the field, a comprehensive, comparative overview that critically examines the relationships between synthesis strategies, interfacial chemistry, structure-property correlations, and application potentials of these materials remains lacking. This review aims to fill that gap by offering an in-depth exploration of geopolymer-based composites and hybrids, focusing particularly on the chemistry of interactions at the organic–inorganic interface, the mechanisms underpinning performance enhancement, and the emerging uses of these systems in advanced domains such as catalysis, pollutant adsorption, energy storage, and fire-resistant insulation. The paper highlights the versatility of geopolymers as a sustainable platform for next-generation functional materials, while also identifying current limitations and outlining key directions for future research and industrial scalability.