No abstract

Many ion channels in the cell membrane are believed to function as gates that control the water and ion flow through the transitions between an inherent hydrophobic state and a stimuli-induced hydration state. The construction of nanofluidic gating systems with high gating efficiency and reversibility is inspired by this hydrophobic gating behavior. A kind of electrically actuated nanochannel is developed by integrating a polypyrrole (PPy) micro/nanoporous film doped with perfluorooctanesulfonate ions onto an anodic aluminum oxide nanoporous membrane. Stemming from the reversible wettability switch of the doped PPy film in response to the applied redox potentials, the nanochannels exhibit highly efficient and reversible gating behaviors. The optimized gating ratio is over 10 , which is an ultrahigh value when compared with that of the existing reversibly gated nanochannels with comparable pore diameters. Furthermore, the gating behavior of the electrically actuated nanochannels shows excellent repeatability and stability. Based on this highly efficient and reversible gating function, the electrically actuated nanochannels are further applied for drug delivery, which achieves the pulsatile release of two water-soluble drug models. The electrically actuated nanochannels may find potential applications in accurate and on-demand drug therapy.

No abstract

Although monovalent lithium has been successfully used as a coloring ion in electrochromic applications, it still faces the challenges of low safety, high cost, and limited reserves. Herein, we demonstrate that the amorphous WO3 films intercalated with Al3+ ions could exhibit desired wide optical modulation (∼63.0%) and high coloration efficiency (∼72.0 cm2 A–1, which is >100% higher than that with Li+ or Na+), benefiting from the three-electron redox properties of aluminum. Due to the strong electrostatic force and large atomic weight, the charge exchange processes for Al3+ ions are limited only to the near-surface region and consequently bring about enhanced electrochromic stability. Our findings provide in-depth insights into the nature of electrochromism and also open up a new route toward scalable electrochromic devices using sputtering techniques and earth-abundant materials.

Schematically deciphering the electrochemical mechanism of the electrochromic NiOx thin film based on the Li+-ion electrolytes.