Strong and Tough Eutectogels with Broad-Range Tunable Mechanical Properties via the Hydrogen Bond Network-Specific Effect

Eutectogels represent promising materials for technological applications due to their excellent ionic conductivity, thermal and electrochemical stability, and nonvolatility. Nonetheless, most existing eutectogels suffer from low strength and toughness. Herein, a strategy to broadly alter the mechanical properties of eutectogels by tuning the aggregation states of polymer chains through the specific hydrogen bond network of a deep eutectic solvent is reported. The prepared eutectogels exhibit exceptional mechanical properties, including record-breaking toughness (203.38 MJ m −3 ) and strength (31.53 MPa), outperforming even the toughest reported eutectogels and surpassing synthetic polymers such as PDMS, synthetic rubber, and natural spider silk. By tailoring the deep eutectic solvent's hydrogen bond network through careful selection of the number and types of hydrogen bonding functional groups, the mechanical properties of eutectogels can be precisely tuned across a wide range. Specifically, tensile strength is adjusted from 8.19 to 31.53 MPa, toughness from 69.84 to 203.38 MJ m −3 , and modulus from 3.38 to 13.01 MPa. Given the diversity of deep eutectic solvents, the proposed strategy allows for rational design of their hydrogen-bond networks to further optimize the mechanical properties of eutectogels, providing a versatile approach for the controlled preparation of high-strength, tough eutectogels.