Organohydrogels with adaptive surface wettability enabled by polyacrylamide/polysiloxane emulsion-based heteronetworks

Hydrogel-based soft materials have attracted significant attention in various fields due to their high water content, good biocompatibility, and variable mechanical strength. However, due to the hydrophilic properties of hydrogel networks, most of the hydrogel-based soft materials are easy to swell in water and have monotonous surface wettability. Here, taking advantage of the intrinsic hydrophobicity of siloxane, novel heteronetwork organohydrogels were synthesized by covalently integrating reactive siloxane monomers into the hydrophilic hydrogel networks via emulsion polymerization. The surface of the heteronetwork organohydrogels exhibited adaptive wettability owing to the rearrangement of the surface chemistry induced by varying solvent conditions. Moreover, the heterogeneous networks endowed organohydrogels with excellent anti-swelling abilities in water or oil (n-heptanes). The potential application of the prepared organohydrogels in the field of oil/water separation was also preliminarily explored. The idea and method of integrating polysiloxane into hydrogels in this study might provide a new insight to develop high-performance polysiloxane-based heteronetwork gel materials.