Tough, low-friction and homogeneous physical hydrogel by a solvent-inducted strategy

Physical hydrogels composed of non-covalent interacting networks have received high attention for their excellent mechanical properties and environmental friendliness, and widely applied as artificial tissues. However, it remains a challenge to synthesize a tough hydrogel via a facile approach. Based on the grafting and spontaneous gelation of PVA and CBA under the mixed solvent, a highly transparent, rapidly formed organohydrogel derived from a structural network between mixed solvent was prepared, whose mechanical properties and gel rate can be regulated by the molar fraction of DMSO. The operation barely reflected phase separation and whitening from hydrophobic interactions despite the exist of water molecules. The hydrogel with crystal domain and hydrophobic domain as strong crosslinks and hydrogen bond as weak cross-linked points by a solvent-inducted strategy, was tough and low-friction. The entire preparation of hydrogel highlights a simple and efficient solvent conversion strategy suitable for gel synthesis with an interaction between polymer and solvent.