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Supra-micellar structures and reentrant effect of the assembled micelles can be observed in the self-assembly of polyelectrolyte copolymers in trivalent salt solution.

As an efficient, controllable, economical, green and low-carbon soil remediation technology, bio-slurry remediation technology can be used for bioremediation of various organic contaminated soils.

Electrochemical energy storage has become a key part of portable medical and electronic devices, as well as ground and aerial vehicles. Unfortunately, conventionally produced supercapacitors and batteries often cannot be easily integrated into many emerging technologies such as smart textiles, smart jewelry, paper magazines or books, and packages with data-collection or other unique capabilities, electrical cables, flexible wearable electronics and displays, flexible solar cells, epidermal sensors, and others in order to enhance their design aesthetics, convenience, system simplicity, and reliability. In addition, conventional energy storage devices that cannot conform to various shapes, are typically limited to a single function, and cannot additionally provide, for example, load bearing functionality or impact/ballistic protection to reduce the system weight or volume. Commercial devices cannot be activated by various stimuli, be able to self-destroy or biodegrade over time, trigger drug release, operate as sensors, antennas, or actuators. However, a growing number of future technologies will demand batteries and hybrid devices with the abilities to seamlessly integrate into systems and adapt to various shapes, forms, and design functions. Here we summarize recent progress and challenges made in the development of mostly nanostructured and nanoengineered materials as well as fabrication routes for energy storage devices that offer (i) multifunctionality, (ii) mechanical resiliency and flexibility and (iii) integration for more elegant, lighter, smaller and smarter designs. The geometries of device structures and materials are considered to critically define their roles in mechanics and functionality. With these understandings, we outline a future roadmap for the development, scaleup, and manufacturing of such materials and devices.

Traditional polyolefin separators tend to perform poorly against heat-triggering reactions causing potentially catastrophic issues in lithium-ion batteries (LIBs). In this study, we developed a high temperature resistant, flexible, mechanically robust and highly ionically conductive composite separator made from electrochemically stable polymer encased with nanodiamonds (NDs). We systematically study the effect of ND concentration in the polymer matrix of the membrane to improve the thermal, mechanical and electrochemical properties of the composites. When tested in LIB with high-voltage LiNiMnCoO2 (NMC), these novel separators exhibited substantially superior performance when compared with commercial polyolefin separator membranes. These cells exhibited closed-to-theoretical capacity (200mAhg-1 NCM), excellent rate capability and minimal degradation for over 150 cycles. Our study showcased the capability of ND powder as a nano-sized filler materials for the fabrication of composite membranes with superior properties, and opened up the broad possibilities of composite membrane fabrications by varying the polymer composition, micro-structure, nanoparticle surface chemistry and concentrations.

Separators play an important role in battery electrochemistry and safety. In general, a good separator is required to be both physically and chemically stable, avoiding unwanted reactions with strong oxidizing or reducing electrolytes near the cathode and anode surfaces, while maintaining mechanical strength avoiding failures despite the cyclic mechanical stresses during battery operation.[1] Separator is also needed to be wettable by the electrolyte and sufficiently porous to provide low resistance to ion transport and enable fast charging. Currently, most commercial separators based on polyolefin such as polyethylene (PE) and polypropylene (PP) are widely used in lithium-ion batteries (LIBs). However, polyolefin separators suffer from low heat resistance due to their low melting points (usually Compared to PP or PE, polyetherimide (PEI) has a higher melting point (> 300 ℃). Porous PEI separator membranes can be fabricated via phase inversion method [2] to provide good ion conductivity and a higher heat resistance. Yet, the weak tensile/puncture strength could make it vulnerable towards mechanical damages during battery cycling. PEI also experiences severe shrinkage at high temperatures (>240 °C). To address these issues, we developed a facile and scalable strategy to incorporate a thin layer of ceramic nanowires on both surfaces of the PEI membrane. Heat resistance tests suggest our separators can survive high temperature up to 400 °C, as the coating minimized the shrinkage of the PEI. The inner polymer layer could melt at elevated temperatures, thus forming a shut-down layer between the ceramic layer to further enhance cell safety. These results indicate our nanowire coated separators can allow batteries to operate safely even at extremely high temperatures. References: [1] M. F. Lagadec, R. Zahn, and V. Wood, “Characterization and performance evaluation of lithium-ion battery separators,” Nature Energy, vol. 4, no. 1, pp. 16–25, Dec. 2018, doi: 10.1038/s41560-018-0295-9. [2] J. Liu et al., “SiO2 blending polyetherimide separator modified with acetylene black/polyvinylpyrrolidone coating layer to enhance performance for lithium‐sulfur batteries,” International Journal of Energy Research, vol. 45, no. 11, pp. 16551–16564, May 2021, doi: 10.1002/er.6902. [3] Q. Wang, J. Yang, Z. Wang, L. Shi, Y. Zhao, and S. Yuan, “Dual‐Scale Al 2 O 3 Particles Coating for High‐Performance Separator and Lithium Metal Anode,” Energy Technology, vol. 8, no. 5, p. 1901429, Mar. 2020, doi: 10.1002/ente.201901429. [4] P. S. Kim, A. Le Mong, and D. Kim, “Thermal, mechanical, and electrochemical stability enhancement of Al2O3 coated polypropylene/polyethylene/polypropylene separator via poly(vinylidene fluoride)-poly(ethoxylated pentaerythritol tetraacrylate) semi-interpenetrating network binder,” Journal of Membrane Science, vol. 612, p. 118481, Oct. 2020, doi: 10.1016/j.memsci.2020.118481.

Supercapacitors have attracted great attention as advanced energy storage devices. However, the low energy density and high cost of electrode materials are the downsides for their practical applications. Here, we introduce a facile and low-cost strategy to develop honeycomb-like Ni3S2 nanosheet arrays (NSAs) as a redox-type electrode for aqueous hybrid supercapacitors (HSCs). Owing to the porous structure of NSAs, the Ni3S2 electrode can show excellent electrochemical performance in 2 M KOH aqueous electrolyte. A high specific capacity of 151.2 mAh g−1 has been achieved at the current density of 3 A g−1. To demonstrate their further applications, HSCs have been assembled with activated carbon (AC) as negative electrode and the assembled devices can successfully work within a large voltage range of 0–1.6 V and deliver a maximum energy density of 35.2 Wh kg−1 at the power density of 491 W kg−1.

Energy transfer between fluorescent dyes and quenchers is widely used in the design of light-up probes. Although dual quenchers are more effective in offering lower background signals and higher turn-on ratios than one quencher, such probes are less explored in practice as they require both quenchers to be within the proximity of the fluorescent core. In this contribution, we utilized intramolecular motion and photoinduced electron transfer (PET) as quenching mechanisms to build super-quenched light-up probes based on fluorogens with aggregation-induced emission. The optimized light-up probe possesses negligible background and is able to detect not only free formaldehyde (FA) but also polymeric FA, with an unprecedented turn-on ratio of >4900. We envision that this novel dual quenching strategy will help to develop various light-up probes for analyte sensing.

Improving efficiency of an adjuvant, material that enhances the body’s immune response to an antigen, has become vital for the development of safer, cheaper, and more effective next-generation vaccines. Commercial vaccines typically use aluminum salt-based adjuvant particles, most commonly aluminum oxyhydroxide (AlOOH) and aluminum hydroxide (Al(OH)3) based, often referred to as “alum”. Despite their broad use, their adjuvant properties are rather moderate. This is even worse in the case of aluminum oxide (Al2O3)-based adjuvant. While being more robust and less cytotoxic, Al2O3 is a significantly less effective adjuvant than above-mentioned Al compounds and is consequently not commonly used. Here, we report on the remarkably enhanced adjuvant properties of Al2O3 when produced in the form of nanowires (NWs). Based on recent advances in understanding neutrophil activation by inert nanoscaffolds, we have created ultra-long Al2O3 NWs with a high aspect ratio of ∼1000. These NWs showed strong humoral immune response with no damaging effect on the microvasculature. Since only the change of shape of Al adjuvants is responsible for the excellent adjuvant properties, our finding holds great promise for rapid implementation as safer and more effective adjuvant alternative for human vaccines. The mechanism behind human blood-derived neutrophil activation with Al2O3 NWs was found to be sequestering of Al2O3 NWs by neutrophils via formation of neutrophil extracellular traps (NETs).

Permanent magnet linear motors can cause thrust fluctuation due to cogging and end effects, which will affect the operation stability of the linear motor. In order to solve this problem, a new method of eliminating alveolar force by using phase-shifting and displacement is proposed in this paper. Taking the cylindrical permanent magnet linear motor as an example, the traditional cylindrical permanent magnet linear motor is divided into two unit-motors, and established finite element analysis model of cylindrical permanent magnet linear motor. It is different from other traditional methods, the thrust fluctuation was reduced by both phase-shifting and displacement simultaneously in this paper, and through simulation analysis, it is determined that the thrust fluctuation suppression effect was the best when the cogging distance was shifted by half. Furthermore, a comparative simulation was made on whether the magnetic insulating material was used. The simulation results show that: The method proposed in this paper can effectively suppress the thrust fluctuation of the cylindrical permanent magnet linear motor. And it can be applied to other similar motor designs. Compared with the traditional method of suppressing thrust fluctuation, the mechanical structure and the technological process of suppressing thrust fluctuation used in this method are simpler.