Nature-inspired dynamic nanoconfinement enables life-like mechanical adaptability and robust environmental resilience in polyurethane-urea elastomers

Abstract

Integrating high mechanical strength, dynamic adaptability, and environmental tolerance in elastomers remains a critical challenge in materials science. Drawing inspiration from coral reef systems, we report a dynamic nanoconfinement strategy for polyurethane-urea (PU) elastomers, leveraging Zn²⁺-mediated coordination between the hydroxyl groups of cellulose nanocrystals (CNCs) and PU carbonyl moieties to construct reversible interfacial interactions. The design achieves 96% self-healing efficiency at ambient temperature through stress-directed bond reconfiguration. Simultaneously, the CNCs network promotes molecular deflection at crack tips, enhancing energy dissipation and enabling outstanding tensile strength (71.5 MPa), stretchability (2207%), and toughness (663.87 MJ m⁻³). Notably, the nanoconfined architecture retains 99% of its mechanical performance after a 1000 h neutral salt spray test (ASTM B117, 35 °C, ≥95% RH, with a 5% NaCl solution at pH 6.5–7.2) and exhibits programmable solvent responsiveness via tunable network dynamics. Furthermore, dynamic surface reconstruction suppresses Pseudomonas aeruginosa biofilm formation by 96%. This hierarchical responsiveness, reminiscent of coral-like environmental intelligence, confers autonomous adaptation to mechanical, chemical, and biological stimuli while preserving structural integrity. This nanoconfinement approach transcends the limitations of conventional elastomers, offering a generalizable blueprint for next-generation adaptive materials with broad implications in marine engineering, biomedical systems, and soft robotics.