Noncovalent cross-linked engineering hydrogel with low hysteresis and high sensitivity for flexible self-powered electronics

In this study,the hydrogel network was reinforced by covalent-like hydrogen bonding,and the strong binding ability of boron-nitrogen coordination served as the main driving force.Among them,acrylamide(AM)and 3-acrylamidophenylboronic acid(AAPBA)were the main body,and the numerous hydroxyl groups in the trehalose(Treh)molecule and other polymer groups formed strong hydrogen bonding interactions to improve the mechanical properties of the PAM/PAAPBA/Treh(PAAT)hydrogel and ensured the simplicity of the synthesis process.The hydrogel possessed high strain at break(1239%),stress(64.7 kPa),low hysteresis(100%to 500%strain,corresponding to dissipation energy from 1.37 to 7.80 kJ/m^(3)),and outstanding cycling stability(retained more than 90%of maximum stress after 200 ten-sile cycles).By integrating carbon nanotubes(CNTs)into PAAT hydrogel(PAATC),the PAATC hydrogel with excellent strain response performance was successfully constructed.The PAATC conductive hydro-gel exhibited high sensitivity(gauge factor(GF)=10.58 and sensitivity(S)=0.304 kPa^(-1)),wide strain response range(0.5%-1000%),fast response time(450 ms),and short recovery time(350 ms),excellent fatigue resistance,and strain response stability.Furthermore,the PAATC-based triboelectric nanogener-ator(TENG)displayed outstanding energy harvesting performance,which shows its potential for appli-cation in self-powered electronic devices.

Fabric-based all-weather-available photo-electro-thermal steam generator with high evaporation rate and salt resistance

Solar-driven steam generation is a practical strategy to harness solar energy for desalination and production of clean water with a minimized carbon footprint.However,this strategy suffers from a low evaporation rate under weak illumination on cloudy days or at night.Herein,we present a fabric-based all-weather-available photo-electrothermal steam generator(P/ET-SG)capable of regulating the surface temperature and evaporation rate by the coupling effect of photo-thermal and electro-thermal heating depending on the light conditions.An unprecedented high surface temperature of 52℃ in the wet state and an evaporation rate of 2.61 kg m^(-2) h^(-1) were achieved by the P/ET-SG under 1 sun with only 1 V input voltage owing to the uniform heat distribution and the coupled electro-thermal source.The oneway fluidic design of the P/ET-SG effectively prevented salt precipitation during continuous desalination in 24 h and was able to remove salt granules from the evaporation surface.Furthermore,the P/ET-SG demonstrated a high evaporation rate of 2.58 kg m^(-2) h^(-1) in the purification of concentrated saline water and dye-contaminated water with high efficiency(>99.9%).This study offers new thoughts for the design of allweather-available solar steam generators with high efficiency and makes a step forward towards fast purification of concentrated saline water and wastewater.