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Supramolecular polymer bottlebrushes (SPBs) consist in the 1D self-assembly of building blocks composed of a self-assembling core with pendant polymer arms. Kinetic hurdles often ...hinder their stimuli-responsiveness in solution. Changing the nature of the solvent should alleviate these hurdles by modulating the self-association strength, leading to stimuli-responsive SPBs.
The SPBs were formed, in various solvents, by hydrogen bond-driven self-assembly of an azobenzene-bisurea decorated with poly(ethylene oxide) polymer arms. The photo-isomerization of the azobenzene unit was studied by UV/visible spectroscopy and proton NMR spectroscopy, whereas the consequences on supramolecular self-assembly were studied by small angle neutron and X-ray scattering.
In water, the assembly was previously shown to be driven by both hydrogen-bonds and strong hydrophobic effects, the latter rendering the system kinetically frozen and the disassembly irreversible. Here we show that in organic solvents such as toluene or chloroform, reversible light-responsive dissociation is achieved. Solvophobic effects in these solvents are expected to be much weaker than in water, which probably allows reversibility of the light-response in the former solvents. The key role of the solvent on the reversibility of the process opens up new perspectives for the design of stimuli-responsive SPBs and their applications in various fields.
The cellular microenvironment is highly heterogeneous and dynamic. Therefore, cells must be equipped with molecular tools to adapt and respond to constantly fluctuating inputs. One such input is ...mechanical force, which activates signalling and regulates cell behaviour in the process of mechanotransduction. Whereas the mechanisms activating mechanotransduction are well studied, the reversibility of this process, whereby cells disassemble and reverse force-activated signalling pathways upon cessation of mechanical stimulation is far less understood. In this review we will outline some of the key experimental techniques to investigate the reversibility of mechanical signalling, and key discoveries arising from them.
•Zn electrode performance in different electrolytes is systematically evaluated.•Zn electrode in mild/slightly acid electrolytes exhibits better cycling stability.•Alkaline electrolyte promises a ...rapid electrode kinetics and a small hysteresis.•Mild/slightly acid electrolytes endow high reversibility.
Zn-based batteries attract extensive attention as the next-generation energy storage devices for both electronics and large power grids due to the high capacity, energy density, low cost, and safety derived from the inherent properties of metallic Zn and the safety of aqueous electrolytes. Herein, the performance variations and critical issues of the Zn electrodes in the alkaline and neutral/slightly acid electrolytes are systematically investigated by evaluating the cycle stability, electrode reaction kinetics, and stripping/plating reversibility in three kinds of electrolytes, including ZnSO4, Zn(CF3SO3)2, and KOH+Zn(CH3COO)2. The lifespan of the Zn electrode in the neutral/slightly acid electrolytes is >1400% higher than the one in the alkaline electrolyte at a current density of 1 mA cm−2. However, the Zn electrode in the alkaline solution exhibits better reaction kinetics and low polarization. Besides, in the neutral/slightly acid electrolytes, higher coulombic efficiency is obtained, corresponding to better stripping/plating reversibility. Therefore, research in neutral/slightly acid electrolytes should focus on elevating the electrode kinetics and reducing polarization, while in alkaline electrolytes, the dendrite, hydrogen evolution, and self-discharge should be treated to elevate the calendar life and reversibility. This work provides a guideline for further construction of high-performance Zn electrodes in different electrolyte systems.
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The application of membrane distillation (MD) to hypersaline wastewater treatment is constrained by mineral scaling. Although tuning membrane surface wettability has been recently used to mitigate ...membrane scaling in MD, the effectiveness of this strategy for different scaling types has not been well understood. Furthermore, two important factors that determine the performance of MD membrane, namely wetting resistance and scaling reversibility, have been rarely discussed in MD scaling studies. In this work, we investigated the effects of membrane surface wettability on pore wetting and scaling reversibility associated with gypsum and silica scaling in MD. We challenged a hydrophobic membrane, a Janus membrane with a hydrophilic top layer, and a superhydrophobic membrane with gypsum- and silica-containing feed solutions. Compared to the hydrophobic and Janus membranes, the superhydrophobic membrane delayed scaling induction and enhanced scaling reversibility in gypsum scaling tests, in which the total water recoveries achieved by the tested membranes were inversely correlated to membrane surface hydrophilicity. Also, the superhydrophobic membrane uniquely resisted pore wetting induced by gypsum scaling, probably by preventing feedwater intrusion into membrane pores. In contrast, altering membrane surface wettability was ineffective to improve either scaling reversibility or total water recovery under silica scaling, which did not induce pore wetting for all the tested membranes. We attributed the differences in scaling behaviors as well as the varied responses to membrane surface wettability between gypsum and silica scaling to their distinct scaling mechanisms. The oriented and intrusive gypsum crystallization resulted in pore deformation and discrete crystals that could be detached by physical cleaning. In contrast, the slow kinetics and lack of orientation of silica polymerization formed a thin and crosslinked scaling layer, which was not intrusive but firmly attached to the membrane surface. The results of our study provide valuable insights on the interplays among membrane surface wettability, scaling type, and membrane performance in MD desalination, and suggest that the development of scaling mitigation strategies in MD should be tailored to the varied mechanisms of different scaling types.
•The effects of membrane wettability on MD gypsum and silica scaling were assessed.•Superhydrophobic membrane is resistant to membrane wetting in gypsum scaling.•Superhydrophobic membrane enhances reversibility of gypsum scaling.•Membrane surface wettability does not improve reversibility of silica scaling.•Distinct behaviors of gypsum and silica scaling are due to varied mechanisms.
The promise of using 2D materials for hydrogen storage has broad prospects, ascribe to their significant specific surface area and lightweight properties. In this work, the hydrogen storage ...capability and reversible storage mechanism of 2D penta-SiCN material are investigated based on the first-principles computational method. Thermal stability of penta-SiCN is calculated by the ab-initio molecular dynamics (AIMD) simulation and root-mean-square displacement (RMSD) algorithm. It has been found that penta-SiCN is thermodynamically stable even after adsorbing hydrogen molecules. Taking into account the benchmarks of average and continuous adsorption energies of the adsorption systems, a pristine 2 × 2 × 1 penta-SiCN substrate has the ability to adsorb up to 26H2 molecules, which results in a maximum hydrogen storage capacity of 10.80 wt%. According to the semi-empirical calculation method that based on the thermodynamic analysis, the penta-SiCN adsorption system has a high reversible hydrogen storage capacity of 9.57 wt% within the adsorption and desorption application working conditions. The results proposed in this study demonstrates that penta-SiCN exhibits considerable promise for hydrogen storage with its substantial hydrogen storage capacity, exceptional reversibility, and eco-friendly characteristics.
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•Pristine penta-SiCN is a promising material for hydrogen storage.•Theoretical predictions by combining DFT and a semi-empirical calculation method.•The gravimetric densities of penta-SiCN can reach 10.80 wt%.•The penta-SiCN has a high reversible hydrogen storage capacity of 9.57 wt% within the adsorption and desorption working environment.
A novel colorimetric and fluorometric dual-channel sensor DA with a favorable optical property and high specificity via a facile synthesis for Cu2+ was developed. DA showed a remarkably rapid ...response and high selectivity for Cu2+ over other metal ions with low detection limit of 15.1 nM. The sensing mechanism of DA for Cu2+ was based on the chelation-enhanced fluorescence quenching (CHEQ) mechanism, and further confirmed by optical measurements, FTIR, HRMS and DFT calculations. Importantly, DA for sensing Cu2+ possessed excellent sensing performances including colorimetric and fluorometric dual-mode detection, fast response, good reversibility, wide pH response range and strong anti-interference ability. Moreover, the DA could be not only applied to quantitatively detect Cu2+ in environmental water, food and drink samples, but also show highly colorimetric detection of Cu2+ on test strips and silica, indicating its possibility to be utilized as a convenient and low-cost sensor for environment and food monitoring.
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•A new colorimetric and fluorometric sensor DA was synthesized.•DA exhibits fast response and ultra sensitivity to Cu2+.•DA is successfully used for tracking Cu2+ in environmental water, food and drink samples.•DA served as an efficient optical solid-state sensor for highly colorimetric detection of Cu2+ on test strips and silica.
Metallic Zn is a preferred anode material for rechargeable aqueous batteries towards a smart grid and renewable energy storage. Understanding how the metal nucleates and grows at the aqueous Zn anode ...is a critical and challenging step to achieve full reversibility of Zn battery chemistry, especially under fast‐charging conditions. Here, by combining in situ optical imaging and theoretical modeling, we uncover the critical parameters governing the electrodeposition stability of the metallic Zn electrode, that is, the competition among crystallographic thermodynamics, kinetics, and Zn2+‐ion diffusion. Moreover, steady‐state Zn metal plating/stripping with Coulombic efficiency above 99 % is achieved at 10–100 mA cm−2 in a reasonably high concentration (3 M) ZnSO4 electrolyte. Significantly, a long‐term cycling‐stable Zn metal electrode is realized with a depth of discharge of 66.7 % under 50 mA cm−2 in both Zn||Zn symmetrical cells and MnO2||Zn full cells.
Ultrafast metal electrodeposition in fast‐charging Zn batteries was investigated by in situ optical imaging and theoretical modeling. The critical parameters governing the electrodeposition stability of the metallic Zn electrode were uncovered, guided by which a highly reversible Zn metal electrode in an aqueous battery with a depth of discharge of 66.7 % at 50 mA cm−2 was achieved.
The irregular and random electrodeposition of zinc has emerged as a non‐negligible barrier for deeply rechargeable aqueous zinc (Zn)‐ion batteries (AZIBs), yet traditional texture regulation of the ...Zn substrate cannot continuously induce uniform Zn deposition. Here, a Janus separator is constructed via parallelly grown graphene sheets modified with sulfonic cellulose on one side of the commercial glass fiber separator through the spin‐coating technique. The Janus separator can consistently regulate Zn growth toward a locked crystallographic orientation of Zn(002) texture to intercept dendrites. Furthermore, the separator can spontaneously repel SO42− and anchor H+ while allowing effective transport of Zn2+ to alleviate side reactions. Accordingly, the Zn symmetric cell harvests a long‐term lifespan over 1400 h at 10 mA cm−2/10 mAh cm−2 and endures stable cycling over 220 h even at a high depth of discharge (DOD) of 56%. The Zn/carbon nanotube (CNT)–MnO2 cell achieves an outstanding capacity retention of 95% at 1 A g−1 after 1900 cycles. Furthermore, the Zn/NH4V4O10 pouch cell with a Janus separator delivers an initial capacity of 178 mAh g−1 and a high capacity retention of 87.4% after 260 cycles. This work provides a continuous regulation approach to achieve crystallographic homogeneity of the Zn anode, which can be suitable for other metal batteries.
A Janus separator is constructed to continuously regulate the Zn(002) planar electrodeposition on the surface of a Zn anode and provide single‐ion channels for Zn2+ ions to suppress side reactions. This work provides new insights to stabilize metal anodes (e.g., Li, Na, K, Zn, Al, Ca, and Mg) in rechargeable batteries.
•Porous carbon microspheres was used to load methylated polyethylenimide.•mPEI@NCMs can be used as a novel adsorbent for highly-efficient SO2 capture.•mPEI@NCMs showed efficient selection and ...reversible adsorption for SO2.
Solid-supported materials are extensively utilized for SO2 capture. Polytertiary amine compounds, which are abundant in tertiary amine groups, efficiently capture SO2. In this study, we propose the loading of methylated polyethylenimide (mPEI), which is rich in tertiary amine groups, into chitin-derived carbon microspheres (NCMs), which have a robust pore structure and large surface area. The produced adsorbent (mPEI@NCMs) showed good performance for capturing SO2. Further, the adsorption capacity of mPEI@NCMs for SO2 at 25 °C and 1 bar was 12.23–18.12 mmol/g, whereas at 25 °C and 0.01 bar, it was 4.58–6.96 mmol/g. The mPEI@NCMs sample showed good selectivity for adsorbing SO2 from mixtures containing N2 and CO2. Furthermore, mPEI@NCMs showed a good reversible adsorption capacity for SO2.
3D printing and numerical analysis are combined to design a new class of architected materials that contain bistable beam elements and exhibit controlled trapping of elastic energy. The proposed ...energy‐absorbing structures are reusable. Moreover, the mechanism of energy absorption stems solely from the structural geometry of the printed beam elements, and is therefore both material‐ and loading‐rate independent.
