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• A novel stimuli-responsive superhydrophobic film driven by solvent is reported. • The SSF exhibits fast, large-scale, reliable bending actuation for the swelling discrepancy. • The SSF is successfully applied in biomimetic device, electric switch and water manipulation. • The SSF-based actuators can stably work even under wet and humid conditions. Fabrication of functional superhydrophobic materials with stimuli-responsive driving ability for the growing fields such as electric switch and liquid manipulation still remains mysterious and challenging. In this work, a stimuli-responsive superhydrophobic film (SSF) is fabricated by integrating a bottom porous poly(vinylidene fluoride) (PVDF) layer, a sandwiched cross-linkable poly(vinyl alcohol) (cPVA) layer, and a top carbon nanotubes@polydimethylsiloxane (CNTs@PDMS) layer. Induced by the asymmetric swelling of cPVA/PVDF bilayer upon exposure to acetone vapor, the SSFs directionally roll towards the superhydrophobic CNTs@PDMS surface with a large curvature of 0.65 mm−1, a fast response within 10 s, and an excellent fatigue resistance of more than 1000 actuation cycles. Furthermore, the special superhydrophobicity highly ensures the reliable actuation behavior of the SSFs under wet environments. Taking advantage of the conductivity of the CNTs@PDMS layer, the SSF-based electric switches are fabricated and conveniently actuated to control the electric circuit states of turning on/off. Additionally, thanks to the combination of water repellency and acetone vapor-responsive actuation, the SSFs are designed as smart channels for a water control system to successfully achieve the manipulation of liquid flow direction. The findings conceivably stand out as a new methodology to fabricate functional superhydrophobic materials with stimuli-responsiveness for various potential applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A flexible thermoelectric nanocoating with layered heterostructure was constructed. • The nanocoating exhibited accurate detection capability for the temperature rise stage of a fire. • The nanocoating triggered fire-warning within 1.5 s when encountering fire. • The coated polymer materials were difficult to be ignited during burning tests. Thermoelectric materials have attracted considerable interest in the field of fire warning because of the accuracy and repeatability of their thermoelectric effect. Nevertheless, the incompatibility between high thermoelectric efficiency and flexibility restricts their application in flexible electronic materials. Herein, the dilemma was overcome by constructing a flexible thermoelectric nanocoating with layered heterostructure through the co-assembly of thermoelectric graphene (TEG) nanosheets and carboxymethyl cellulose (CCS). Layered heterostructure not only exhibited exceptional flexibility, but also enabled repeatable sensitive thermosensation of the nanocoating. The nanocoating could accurately monitor the temperature rise stage (50–350 ℃) of a fire, and trigger the fire-warning within 1.5 s when encountering flame. Even it was reburned, the nanocoating still triggered the fire-warning within 2.6 s. Besides, the compact layered structure endowed the nanocoating with efficient flame retardancy. The coated polyester film reached a limiting oxygen index of 33.7 % and self-extinguished in vertical burning test. This flexible thermoelectric nanocoating may pave the way toward high fire safety for flexible electronic materials. [ABSTRACT FROM AUTHOR]

With the environmental pollution deteriorating, oil-water separation has attracted much attention in recent years. In this work, a facile method is proposed to fabricate superhydrophobic polyurethane sponge for oil-water separation via a simple dipping-drying process. It is based on the utilization of hydrophobic thiolated graphene (GSH) with the water contact angle (WCA) of 128° from graphene oxide through thiolation reaction. The WCAs of the as-prepared sponges were largely determined by the loading of GSH, and the WCAs reached 157.0° and 160.5° with GSH loadings at 5.0% and 7.5%, respectively. The GSH-based superhydrophobic sponge exhibited high absorption selectivity for different organic solvents and oils, the absorption capacity for chloroform attained 90 times and there was no decrease after 10 absorption cycles. Importantly, with the oil-water separation device composed of pump, rubber tubes and GSH-based sponge, the separation efficiency of toluene from water reached 99.7%, and still maintained 99.5% after 5 cycles. Additionally, GSH-based sponge also effectively shortened burning time and reduced black smoke in the combustion process, demonstrating good flame retardancy. Our findings provided a new strategy to fabricate superhydrophobic materials for oil-water separation, showing the great potential in large-scale practical application. [ABSTRACT FROM AUTHOR]