Enhancing the low-temperature tolerance of electrochemical energy storage devices (e.g. supercapacitors, rechargeable batteries) in a cold climate is important for automobiles, wearable devices, and smart grids used in high-altitude areas and polar regions. Recently, supercapacitors' longevity and performance under varied temperature conditions, especially low temperature, have received widespread attention. However, until now, the sluggish ion diffusion caused by electrolyte freezing restricts the low-temperature performance and durability of supercapacitors. Herein, an innovative solid-state ion conducting ice gel (IG) with a high conductivity (1.79 × 10−4 S cm−1 at −15 °C), favorable flexibility, and significant low-temperature tolerance was designed and prepared by compositing polyvinyl alcohol (PVA) and CuSO4·5H2O salt through ultra-fast liquid nitrogen freezing. Thereafter, a symmetrical configuration supercapacitor was assembled with two flexible electrodes and IG electrolytes. The IG electrolytes feature a distinct solid-state ion conductor that can provide efficient ion transportability to the supercapacitor at extremely cold temperatures with remarkable electrochemical performances. For example, even at −80 °C, the supercapacitor performed well with a capacitance retention rate of 91.8% after 7000 cycles. Besides, the remarkable mechanical properties derived from the IG electrolytes also endow the supercapacitor with great durability under various harsh deformations in sub-zero surroundings. This work will open up a new avenue for developing versatile solid–gel electrolytes with broad working temperature ranges under harsh conditions for portable and wearable energy storage devices.
Kai Cheng,Na Zhang,Na Yang,Shuai Hou,Jiahui Ma,Luhong Zhang,Yongli Sun,Bin Jiang
Zwitterionic materials are well known to possess extraordinary water affinity. However, micromolecular zwitterions have rarely been exploited for membrane hydrophilic modification. Herein, novel antifouling and antibacterial polyvinylidene fluoride (PVDF) ultrafiltration membranes with enhanced permselectivity were facilely fabricated through one-step co-deposition of dopamine and a newly synthesized micromolecular zwitterion (DMAPAPS). With the assistance of CuSO 4 /H 2 O 2 -triggered oxidation, a uniform and hydrophilic coating (water contact angle = 33°) was constructed on membrane surface in only 40 min. The impacts of the DMAPAPS concentration and coating time on membrane performance were investigated. Results showed that our strategy endowed the optimized membrane with high pure water flux of 364 L/m 2 ∙ h and BSA rejection of 98.6%. The flux recovery ratios of membrane were as high as 96.3% for bovine serum albumin, 98.1% for humic acid and 95.1% for sodium alginate after 3-cycle filtration, respectively. Moreover, the membrane displayed superior antibacterial activity towards E. coli and S. aureus as well as excellent chemical and mechanical stability. This work provides a versatile platform for the robust, time-saving and cost-effective fabrication of antifouling and antibacterial membranes.
Guansong Hu,Junjian Chen,Yan Fan,Haiyan Zhou,Kunzhong Guo,Zhou Fang,Liangxu Xie,Lin Wang,Yingjun Wang
As an effective strategy to develop novel implants with a biomolecule, the efficiency of a copper-catalysed azide-alkyne cycloaddition (CuAAC) urgently requires improvement. Herein, we constructed a facile CuAAC system with catalytic CuSO 4 /sodium borohydride (CuAAC-Bor). As Cu nanoclusters (CuNCs) formed in situ , they showed stronger efficiency in immobilizing 41 types of peptides on Ti implants than traditional CuAAC with CuSO 4 /sodium ascorbate. Then, we mechanically revealed the significance of peptide size on CuAAC efficiency by all-atom molecular dynamics simulation and machine learning, and found that larger peptides preferred to adhere to Ti and CuNCs to increase their reaction opportunity. With CuAAC-Bor, HHC36-engineered implants strongly inhibited 5 types of clinical bacteria in vitro and prevented infection in vivo , and RGD-, DGEA-, QK- or YGFGG-engineered implants had high biocompatibilities with HUVECs / hBMSCs in vitro . Moreover, we demonstrated that QK-engineered implants prepared with CuAAC-Bor promoted the osteogenic differentiation of hBMSCs via the PI3K/Akt signalling pathway and triggered angiogenesis and osteogenesis in vivo . Our study shows that this facile and highly efficient CuAAC-Bor system holds high promise for the preparation of novel biomaterial surfaces.
危险品化学品经营许可证（带存储）