Self-Assembly of Organic-Inorganic Copolymers Toward Bio-Inspired Cementitious Composites

Refined by millions of years of rigorous evolution, highly mineralized biological materials have perfected organic-inorganic self-assembly to break the traditional trade-off between strength and damage tolerance. Their rigid-flexible precursor architectures motivate an organic-inorganic copolymerization strategy for the bottom-up design of cementitious materials, the most pervasive and resource-intensive engineered products. Herein, as the primary binding phase in cement, calcium silicate hydrate (CSH) is copolymerized with thioctic acid (TA) into a hybrid precursor through a thermodynamically spontaneous process driven by Lewis acid-base coordination (Ca²⁺-COO^-). Hot pressing promotes the synergistic evolution of amorphous CSH into a denser and structurally reorganized framework together with TA crosslinking, resulting in a self-organized organic-inorganic nanocomposite that resembles the disordered collagen-mineral architecture in trabecular bone. Notably, the poly(CSH-TA) composite features a microphase-homogeneous architecture that delivers an exceptional compressive strength of over 300 MPa at 10% strain. Even more impressively, we demonstrated the intrinsic physical reprocessibility of cementitious materials, allowing retention of over 80% of strength and energy absorption capacity through five consecutive powder-to-bulk cycles. The organic-inorganic copolymerization route opens a bioinspired pathway for next-generation cementitious materials toward achieving multifunctional performance breakthroughs.