Design And Property Of Highly Stretchable,Extreme Environment-adaptive And Ultra-elastic Nanocomposite Hydrogels

Hydrogels are widely used in biological engineering,flexible sensing,energy storage and other fields due to their high biocompatibility and the properties of both fluid and solid.However,with the development of material science,higher requirements are put forward for materials.For hydrogels,their single properties(weak mechanical strength,high temperature water evaporation,low temperature freezing,organic solvent phase separation,etc.)have been unable to meet the needs of human beings.Extreme environment-compatible nanocomposite hydrogels have becoming the research focus of material scientists.Based on this,nanocomposite hydrogels with high strength,super elasticity and extreme environment compatibility were constructed by dual hetero-network and emulsion hybrid crosslinking strategies.The specific research contents of this paper are as follows:1.Silver nanowires,acrylamide,N,N-dimethyldiacrylamide,potassium perdisulfate and methylethylenediamine were used for orientation freezing and placed overnight to form homogeneous porous silver nanowires with polymer wall structure of ultra-elastic hydrogel.Then the ultra-elastic hydrogel was used as the substrate,acetone was dehydrated,silver nanowires and polymer walls were modified by the formation of silver-sulfur coordination bonds by the light initiator 907,and finally the organic hydrogel pressure sensor with heterogeneous network was formed by the immersion of oily precursor solution and ultraviolet light polymerization.The organic hydrogel exhibits excellent super-elasticity,fatigue resistance,low temperature resistance,and oil expansion resistance.It can be well restored to its original shape under compression deformation of 70%.It can maintain a high load-unloading cycle even in-50 ~oC and different oil environment,and has excellent pressure sensitivity.2.Homogeneous micro-spheres are formed in the aqueous phase by using amino-terminated polydimethylsiloxane under the action of sodium dodecyl sulfate and with a certain temperature.The gold nanoparticles were formed in situ around the microspheres at a certain temperature by slowly dropping the chloric acid solution,and the emulsion hybrid macromolecule crosslinking agent was constructed by modifying core-shell with N,N-bis(acrylyl)cystamine.Finally,the hydrogel three-dimensional network was constructed to form multifunctional nanocomposite hydrogels.The nanocomposite hydrogels show excellent mechanical strength,super elasticity,good adaptability to extreme environments.They are restored to their original length under tensile condition of 3000%(2.3 MPa)and could maintain excellent mechanical elasticity at-20～90 ~oC,show excellent performance in resisting poor solvents and good photothermal conversion capacity.Therefore,the nanocomposite hydrogel material has a good application prospect in a broader field.