Nanoengineered geopolymer composites with biomass-based 2D graphitic carbon nanoplatelets

This research studied an innovative method for improving the properties of fly ash-based geopolymer mortar by using ultrafine two-dimensional (2D) graphitic carbon nanoplatelets (GCNPs) derived from sustainable biomass sources. These low-cost and eco-friendly GCNPs were synthesized through a thermochemical process involving biomass-derived sucrose solution. Both fly ash and GCNPs were processed and activated to optimize their performance in the geopolymerization process. The graphitic carbon reinforced geopolymer mortar (GCGPM) composite was optimized by employing different dosages of GCNPs (0, 0.1, 0.2, 0.3% [by weight of binder]), and the resulting GCGPM was examined through various instrumental analyses. It was observed that the addition of GCNPs results in reduced workability of the geopolymer mortar. Importantly, the maximum compressive strength of the GCGPM was significantly enhanced, up to 34.21%, with a 0.2% GCNPs addition over a 28-day curing period. Furthermore, incorporating 0.1% GCNPs into the composite led to an increased composite density, resulting in a substantial reduction of water absorption, up to 76.49%. These outcomes hold promise for achieving a more compact microstructure through the integration of GCNPs into geopolymer composites. The study suggests that novel synthesized GCNPs can effectively and sustainably enhance the properties of geopolymer composites in a cost-effective manner.