Strong and Multifunctional Geopolymer Composites: A Multi-Scale Study

Geopolymers are amorphous inorganic polymers that result from the reaction between an aluminosilicate source and an alkali metal hydroxide or silicate solution. They present various appealing attributes such as rapid hardening, early strength, low shrinkage, freeze-thaw resistance and excellent acid resistance. Potential applications of geopolymers include low-carbon Portland cement alternative, low-level nuclear waste containment, heavy metal waste encapsulation, and biomaterials for bone regeneration. Despite a wealth of studies, the origin of the strength of geopolymer composites is not fully understood. Novel multi-scale computational approaches are needed that can connect the effective response to the micro and nano- constituents. Our research goal is to employ continuum and computational micromechanics along with nanoscale mechanical characterization methods to further the understanding of the relationships between composition, processing, microstructure and properties in geopolymer composites. Here is our driving hypothesis: the nano-porous and nano-granular nature of geopolymer precursors (poly-sialate or poly-sialate-siloxo, and poly-sialate-disiloxo) drives the mechanical behavior of geopolymer hybrids at the macroscopic length scale.