Mechanically robust smart hydrogels enabled by an organic-inorganic hybridized crosslinker

The emerging soft electronics and robots are eagerly seeking for soft materials possessing not only comprehensive mechanical properties but also smart stimuli-responsive property, whose fabrication however remains a great challenge. Herein, we develop a series of high-performance smart hydrogels crosslinked and reinforced by an organic-inorganic hybridized crosslinker composed of multi-functional polymer adsorbed molybdenum disulfide (v-MoS 2 ). The multi-functional polymer is synthesized by grafting polyethyleneimine with multiple vinyl groups. Such molecular design enables it to serve as a surfactant to assist the exfoliation and stabilization of v-MoS 2 nanosheets through hydrophobic and electrostatic interactions , thereby forming the hybridized crosslinker to crosslink polyacrylamide (PAM) hydrogels through both chemical bonds and physical interactions. The crosslinking points can effectively transfer load between the molecular chains and v-MoS 2 , and moreover dissipate energy through hydrophobic and electrostatic interactions. Therefore, the hydrogels not only are mechanically robust with tensile strain up to 3500% and strength up to 645 kPa, but also show outstanding notch-insensitivity and anti-fatigue property. Combining with the photothermal effect of MoS 2 , robust biomimetic fish and butterfly with dual photoresponsivity and thermosensitivity are designed, which can well mimic the self-defense process of marine and terrestrial organisms under external stimulations.