A Moldable, Tough Mineral-Dominated Nanocomposite as a Recyclable Structural Material

Flexible hybrid minerals, primarily composed of inorganic ionic crystal nanolines and a small amount of organic molecules, have significant potential for the development of sustainable structural materials. However, the weak interactions and insufficient crosslinking among the inorganic nanolines limit the mechanical enhancement and application of these hybrid minerals in high-strength structural materials. Inspired by tough biominerals and modern reinforced concrete structures, this study proposes introducing an aramid nanofiber (ANF) network as a flexible framework during the polymerization of calcium phosphate oligomers (CPO), crosslinked by polyvinyl alcohol (PVA) and sodium alginate (SA). This approach allows the flexible inorganic nanolines formed through CPO polymerization to be integrated into the organic framework, thereby creating tough mineral-based structural materials (inorganic content: 70.7 wt.%), denoted as PVA/SA/ANF/CPO (PSAC). The multiple intermolecular interactions between the organic and inorganic phases, combined with the integrated nano-reinforced concrete structure, endow PSAC with significantly enhanced tensile strength (86.6 ± 8.6 MPa), comparable to that of high-strength polymer plastics. Moreover, PSAC possesses excellent plasticity and flame retardancy. The noncovalent molecular interactions within PSAC enable efficient recyclability. Consequently, PSAC has the potential to replace high-strength polymer plastics and structural components, providing a promising avenue for developing high-strength and toughness mineral-based structural materials.