Ultrastrong eutectogels engineered via integrated mechanical training in molecular and structural engineering

Ultrastrong gels possess generally ultrahigh modulus and strength yet exhibit
limited stretchability owing to hardening and embrittlement accompanied by
reinforcement. This dilemma is overcome here by using hyperhysteresis
mediated mechanical training that hyperhysteresis allows structural retarda
tion to prevent the structural recovery of network after training, resulting in
simply single pre-stretching training. This training strategy introduces deep
eutectic solvent into polyvinyl alcohol hydrogels to achieve hyperhysteresis
via hydrogenbondingnanocrystalsonmolecularengineering,performssingle
pre-stretching training to produce hierarchical nanofibrils on structural engi
neering, and fabricates chemically cross-linked second network to enable
stretchability. The resultant eutectogels display exceptional mechanical per
formances with enormous fracture strength (85.2MPa), Young’smodulus
(98 MPa) and work of rupture (130.6MJm−3), which compare favorably to
those of previous gels. The presented strategy is generalizable to other sol
vents and polymer for engineering ultrastrong organogels, and further
inspires advanced fabrication technologies for force-induced self-reinforce
ment materials.