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The classic vibration energy collector has functional restrictions, and it can only collect vibration energy in one or two dimensions. At the same time, it has issues with low output power in the low-frequency vibration region and a limited reaction frequency range. This research proposes a segmented nonlinear broadband piezoelectric–magnetic coupled energy collector capable of collecting vibration energy in different directions. The collector is equivalent to current state-of-the-art research in that it can collect vibration energy in three dimensions while also having a wide collection frequency and a high power density. The collection consists of a hemispherical support structure and four fundamental piezoelectric beam collision components. The rationality of the collision segmentation nonlinear principle is first clarified through theoretical calculation and analysis, and then the collision design is applied between the ends of different cantilever beams to broaden the captured energy frequency band, while parallel piezoelectric beams use a 45° tilt treatment to fully utilize the geometrical properties of the tilted beams for multidirectional energy collection. In addition, the collector introduces a magnetic coupling effect to create a bistable structure via magnetic contact. Comsol 5.6 software is used to model and simulate the planned 45° tilted beam structure, which clarifies the piezoelectric beam's linear intrinsic frequency characteristics and multi-directional geometric aspects. To further verify the collector's validity, a physical model is built and a vibration experiment apparatus is created. The experimental results demonstrate that the collector's effective bandwidth range is up to 6.3 Hz under 1 g acceleration excitation, representing a 125.0% increase in bandwidth when compared to the cantilever beam with a linear array. At 14 Hz frequency, the collector produces a maximum total output power of 19.52 mW and a power density of up to 3211uW cm−3 when excitation is provided in the Z -direction. [ABSTRACT FROM AUTHOR]

Polybenzimidazole (PBI) membranes are considered promising for the energy field, but are restricted by their unsatisfactory ionic conductivity. Thermoplastic phenolic resins (TPPRs) bearing abundant hydroxyl polar groups can contribute to the ionic transport of the PBI membranes. Herein, the interaction of PBI with TPPR introduced abundant hydrogen bonds, forming a hydrogen-bond dominated PBI/TPPR membrane with multiple ion channels to facilitate OH– transport. Moreover, C-PBI/TPPR semi-interpenetrating network (C-PBI/TPPR-sIPNs) membranes with multi-anchored sites were obtained by further cross-linking, which improved the stability. Molecular dynamics (MD) and density functional theory (DFT) simulations further confirmed that the hydrogen bonds between PBI and TPPR resulted in the formation of multiple ion transport channels in the membrane, strengthening the vehicle and Grotthuss transport mechanisms. As a result, the hydroxide ion conductivity of the novel membrane increased by approximately 2 times, and the membrane exhibited good durability. More importantly, these novel membranes were successfully applied in alkaline water electrolysis. This study will inspire further investigations on the binding mode and ion transport mechanism of PBI with other hydroxyl-containing species. [ABSTRACT FROM AUTHOR]

Previous investigations have shown that it is difficult to acquire the infrared (IR) spectra of M+(H2O) (M = Cu, Au) using a single IR photon by attaching an Ar atom to M+(H2O). To explore whether the IR spectra can be obtained using the two Ar atoms tagging method, the geometrical structures, IR spectra and interaction energies are investigated in detail by ab initio electronic structure calculations for M+(H2O)Ar2 (M = Cu, Au) complexes. Two conceivable isomeric structures are found, which result from different binding sites for two Ar atoms. CCSD(T) calculations predict that two Ar atoms are most likely to attach to Cu+ for the Cu+(H2O)Ar2 complex, while the Au+(H2O)Ar2 complex prefers the isomer in which one Ar atom attaches to an H atom of the H2O molecule and the other one is bound to Au+. Moreover, the calculated binding energies of the second Ar atom are smaller than the IR photon energy, and so it is possible to obtain the IR spectra for both Cu and Au species. The changes in the spectra caused by the attachment of Ar atoms to M+(H2O) are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Previous investigations have revealed that it is difficult to acquire the infrared spectra of M+(H2O)2 (M=Cu, Ag, Au) through one infrared photon absorption. To explore whether the infrared spectra can be obtained using Ar atom tagging method, ab initio electronic structure calculations are carried out to investigate the geometrical structures, binding energies and infrared spectra of M+(H2O)2Ar (M=Cu, Ag, Au). Theoretical studies predict that for M+(H2O)2Ar (M=Cu, Ag) there are two isomeric structures which result from different binding sites of Ar atom, while only one isomer structure with the Ar atom bound to H atom is found for Au+(H2O)2Ar. With regard to Ag+(H2O)2Ar complex, the Ar atom tends to attach to M+, while Cu+(H2O)2Ar prefers the isomer which the Ar atom binds to H atom of the water molecular. Moreover, the calculated binding energies of the Ar atom are smaller than the infrared photon energy, and so it is possible to obtain the infrared spectra for M+(H2O)2Ar (M=Cu, Ag, Au) complexes. The changes in the spectra caused by the attachment of Ar atom to M+(H2O)2 are discussed. [ABSTRACT FROM AUTHOR]

AbstractAiming at the problems of high environmental vibration frequency, low output power and short life of the energy harvesters, a noncontact magnetically coupled piezo-electromagnetic rotary energy harvester is proposed in this paper. It consists of a base, a top cover, a rotating body, a cantilever beam, a permanent magnet, a coil, a hollow tube and a clamp. The novel hybrid harvester can produce both piezoelectric and electromagnetic energy at the same time, and in addition, it can efficiently generate electricity at low ambient vibration. Moreover, the piezoelectric material is protected from direct collision by noncontact magnetic coupling excitation. In order to conduct a comprehensive study on the performance of the piezoelectric-electromagnetic rotary energy harvester, we set up a rotating test platform to carry out systematic test verification, and to determine the distance between the permanent magnet and the rotating body and the number of permanent magnets on the rotating body. The test results show that when four permanent magnets are uniformly pasted on the rotating body and the rotating speed is 775 r/min, the piezoelectric and electromagnetic output power are 3.4 mW and 2.69 mW, respectively, and the total hybrid output power is 6.09 mW. [ABSTRACT FROM AUTHOR]

The plastic waste accumulation requires facile yet effective solutions. Currently mechanical recycling typically leads to downcycling, while the environmental footprint of chemical recycling is often unacceptable. Here, we introduce a dual circularity concept, where rational molecular design paves the way for complementary closed-loop mechanical and chemical recyclability under mild conditions. Very small changes in macromolecular structures, thermal and mechanical properties were observed, after as many as six repeated mechanical recycling cycles, showing that a wide processing window could be the key for closing the mechanical recycling loop. Facile, time and energy efficient closed-loop chemical recycling into products with identical performance to original ones was also realized, thanks to the abundant free volume and accessible ester-functionalities. With these design criteria at hand, dual circulation in recyclability can be realized; proceeding with mechanical recycling when we can, and switching to chemical recycling when we must., (© 2025 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Thin-film composite reverse osmosis membranes have remained the gold standard technology for desalination and water purification for nearly half a century. Polyamide films offer excellent water permeability and salt rejection but also suffer from poor chlorine resistance, high fouling propensity, and low boron rejection. We addressed these issues by molecularly designing a polyester thin-film composite reverse osmosis membrane using co-solvent-assisted interfacial polymerization to react 3,5-dihydroxy-4-methylbenzoic acid with trimesoyl chloride. This polyester membrane exhibits substantial water permeability, high rejection for sodium chloride and boron, and complete resistance toward chlorine. The ultrasmooth, low-energy surface of the membrane also prevents fouling and mineral scaling compared with polyamide membranes. These membranes could increasingly challenge polyamide membranes by further optimizing water-salt selectivity, offering a path to considerably reducing pretreatment steps in desalination.