In Situ Ordered Glassification of Gels for Exceptional Stiffness and Toughness

ABSTRACT Glassy gels are indispensable for applications ranging from structural composites to bioelectronics, yet their design is plagued by an intrinsic paradox where the rigid molecular constraints that endow high stiffness simultaneously restrict polymer chain dynamics, precluding the energy dissipation mechanisms essential for toughness. Here, we circumvent this fundamental trade‐off through an in situ molecular constraint‐induced ordered glassification strategy. By restricting localized conformations within a confined hydration environment, we drive the spontaneous assembly of long‐range ordered, load‐bearing nanodomains within a soft gel matrix. These domains function as rigid sacrificial units during initial deformation. Critically, they undergo a progressive, strain‐activated dissociation that redistributes local stress and dissipates mechanical energy at the bulk scale. Unlike conventional post‐treated gels, our material undergoes a rubbery‐to‐glassy transition in situ without external intervention, yielding a 3500‐fold modulus enhancement and a toughness of 289 MJ m −3 , exceeding many reported high‐modulus hydrogels and ionic gels. Furthermore, this molecular design imparts multimodal functionality, including strong yet water‐removable adhesion (∼17 MPa to glass), superior impact resistance, and water‐responsive shape programmability. This ordered glassification paradigm establishes a versatile molecular engineering route to create load‐bearing gels that synergistically integrate stiffness, toughness, and adaptive intelligence, redefining the performance envelope of hydrated soft matter.