A self-healing and self-adhesive chitosan based ion-conducting hydrogel sensor by ultrafast polymerization.

Recently, owing to the wide applications in electronic skin and human activity monitoring, flexible hydrogel strain sensors have attracted great attention. And the better preparation with more efficient is always common aspiration. In this work, acrylamide (AM) was in situ polymerized in chitosan (CS) matrix to prepare hydrogels (PAM@CS). Inspired by the adhesion of natural mussels, plant polyphenol tannic acid (TA) was introduced into the system, Fe3+ was also introduced as redox agent to perform an ultrafast polymerization, and the composite hydrogel PAM@CS/TA-Fe can be prepared at 60 °C within 1 min. The hydrogels are ion conductive and show good sensing performance in detecting major and subtle body motions. Benefiting from the multiple dynamic noncovalent bonds, the PAM@CS/TA-Fe hydrogels also show excellent adhesion performance and good self-healing property, which would expand their application range in wearable and flexible electronic equipment.

Drought changed soil organic carbon composition and bacterial carbon metabolizing patterns in a subtropical evergreen forest.

Subtropical forests are considerable carbon sinks in the northern hemisphere, yet are increasingly suffering from the impact of extreme drought. To better understand the dynamics and kinetics of forest soil carbon storage under long-term drought, a rainfall-reduction experiment was established in a subtropical evergreen forest of eastern China. Soil organic carbon (SOC) composition, microbial carbon metabolism and the interactions with soil microbial community structure were investigated across different soil aggregate size fractions. After five years' treatment of rainfall reduction, a significant loss of large macroaggregates, as well as an increase of microaggregates by over 100% was observed. Meanwhile, drought changed the composition of SOC, reducing the non-hydrolyzed carbon and humin contents in large- to medium-size macroaggregates. Microbial metabolizing capacity of polymeric compounds was also reduced especially in the above aggregate fractions, whereas the utilization of small-molecular compounds was more impacted in small macroaggregates and microaggregates. The changes in carbon metabolizing patterns were further associated with the abundance changes of specific microbial taxa, revealing the microbially mediated mechanism of soil carbon metabolism under long-term drought. In addition, carbon metabolism in microaggregates was particularly sensitive to the changes of soil moisture, suggesting long-term drought may continually influence the functional resistance of the microbial communities. Taken together, our results provide insights into how biotic and abiotic processes together influence the SOC metabolizing processes, continued monitoring and investigation of which shall contribute to better understanding of the dynamics and kinetics of SOC storage under the impact of long-term drought.

CuS/RGO hybrid photocatalyst for full solar spectrum photoreduction from UV/Vis to near-infrared light.

To make full use of the solar energy, it remains a great challenge for semiconductor photocatalysts to harvest the full solar light spectrum from ultraviolet (UV) to visible even the near infrared (NIR) wavelength. Here we show firstly the CuS/RGO (reduced graphene oxide) hybrid photocatalyst synthesized via a microwave assisted method with full solar light (UV-Vis-NIR) active for efficient Cr(VI) reduction. The CuS/RGO displays high absorption and catalytic activity in the UV, visible and even the NIR light regions. As co-catalyst, RGO can separate and inhibit the recombination of charge carriers, consequently improving the catalytic activity. Only 1wt% RGO emersions can reduce 90% of Cr(VI) under the radiation of light over the full spectrum. Findings may provide a new strategy and substance to expand the utilization range of solar light from UV to visible even the NIR energy.