A dual-component strategy for ambiently-cured high-toughness red mud-based geopolymer: Modified nano-TiO2 and sodium polyacrylate

• The combination of 3 wt% silane-modified nano-TiO2 and 0.5 wt% sodium polyacrylate yields a red mud-based geopolymer with 28-day compressive strength of 43.40 MPa and flexural strength of 8.16 MPa, meeting Portland cement 42.5 standards. • Surface modification of nano-TiO2 with glycidoxypropyltriethoxysilane improves dispersibility and interfacial bonding, while sodium polyacrylate enhances fracture toughness, synergistically overcoming brittleness. • Microstructural analyses (XRD, FT-IR, SEM-EDS) confirm increased geopolymer gel formation, reduced crystallinity, and improved polymerization degree, validating the toughening mechanism. • This dual-component strategy offers a sustainable, high-toughness alternative for construction materials, addressing the environmental challenge of red mud disposal.