Elastic geopolymer based on nanotechnology: Synthesis, characterization, properties, and applications

Geopolymers are an economical, durable and environmentally friendly building material that achieves ultimate strength superior to concrete within hours and can withstand extreme high temperatures without degradation, but they lack elasticity and have poor flexural strength. To tackle these challenges, this paper presents a novel nanotechnological and affordable method to produce an elastic geopolymer that can be used as a construction material. Specifically, we report a simple and straightforward strategy that combines electrospinning and the sol-gel process to construct geopolymer nanofibers with superelasticity, extreme durability, and fire resistance. In order to improve the safety level of building construction sites that experience extreme conditions, such as freeze-thaw deterioration, the geopolymer nanofibers can be further functionalized by incorporating various functional components. In this study, Fe3O4 nanoparticles (NPs) adsorbed by an electric double layer structure were dispersed in a geopolymer sol (SAPOs). Elastic geopolymer nanofibers embedded with Fe3O4 nanoparticles were then prepared (Fe3O4/SAPOs) by an electrospinning method. Nanofibers constructed by such a compound method could have superparamagnetic behaviors and stable chemical properties. When Fe3O4/SAPOs are exposed to an alternating magnetic field, eddy currents are generated that cause the geopolymer nanofibers to heat up. This self-heating behavior is a powerful feature that enhances the freeze-thaw resistance of building materials at high altitudes. The nanotechnological route of this study could provide novel insights into the development of advanced construction materials.