Programmable Water/Light Dual-Responsive Hollow Hydrogel Fiber Actuator for Efficient Desalination with Anti-Salt Accumulation

摘要

An intelligent fiber actuator that can sense, adapt, and interact with environmentalstimuli is highly desirable for numerous applications. However,conventional fiber sensors have difficulty in responding to complex environmentswith fast sensing and actuation. Herein, water/light dual-responsivedouble-twisted RGO@HHF (hollow hydrogel fiber loaded with reducedgraphene oxide) actuators are successfully developed based on dynamicself-contraction/elongation via twisting, folding, plying, and re-plying process.Under stimuli by water and light, the twisted RGO@HHF provides a forwardand reverse torsional stroke of 3168 and 60° cm~(?1), respectively. The excellentswelling properties endow the fiber with highly effective water-responsiveability, and the hollow structure can reduce the water required for fiber toswell. Meanwhile, the RGO loading further accelerates water evaporation andenhances the light response rate of the fiber. After twisting and re-plying, thedouble-twisted RGO@HHF exhibits highly increased elongation and contractionunder light/water stimulation. On this basis, a new strategy is proposedfor efficient desalination and anti-salt accumulation. The double-twistedRGO@HHF can elongate to absorb water and contract to evaporate seawaterunder sunlight/water stimulation, respectively. The accumulated salt can bedissolved in the seawater during the dynamic process. This study provides apromising approach for realizing sustainable seawater desalination.