Synthesizing Organo/Hydrogel Hybrids with Diverse Programmable Patterns and Ultrafast Self-Actuating Ability via a Site-Specific In Situ Transformation Strategy

A simple yet robust strategy called 'in situ' transformation is developed to prepare organo/hydro binary gels based on the aminolysis of poly(pentafluorophenyl acrylate) (pPFPA). Treated with desired hydrophilic, oleophilic alkylamines, and their mixtures, pPFPA-based organogels can be thoroughly transformed to targeted hydrogels, organogels, and even organohydrogels with outstanding mechanical properties. Further, relying on programed aminolysis procedures, site-specific in situ transformation can be realized, giving rise to organo/hydro binary gels with diverse patterns and morphologies, such as macroscopic layered organo/hydrogel with a smooth-transitioned yet mechanically robust interface, reconfigurable microscale organo/hydrogel hybrids with a high spatial-resolution pattern capable of reversibly transforming between 2D sheets and 3D helixes with controlled chirality in different solvents, and core-shell structured organo/hydrogel hybrids with readily adjustable core/shell dimensions, tunable internal stress, and transparency. Finally, an oscillator based on a bilayered organo/hydrogel hybrid is developed. Attributing to the synergistic effect of organogel expansion and hydrogel contraction, as well as the robust interfacial mechanical properties, this oscillator is capable of ultrafast self-actuating through harvesting surrounding chemical and thermal energy. This work provides new design principles and highly efficient synthetic strategy for organo/hydro binary gels, and expands their potential applications in soft robotics.