Challenges and Strategies for Synthesizing High Performance Micro and Nanoscale High Entropy Oxide Materials.

High-entropy oxide micro/nano materials (HEO MNMs) have shown broad application prospects and have become hot materials in recent years. This review comprehensively provides an overview of the latest developments and covers key aspects of HEO MNMs, by discussing design principles, computer-aided structural design, synthesis challenges and strategies, as well as application areas. The analysis of the synthesis process includes the role of high-throughput process in large-scale synthesis of HEOs MNMs, along with the effects of temperature elevation and undercooling on the formation of HEO MNMs. Additionally, the article summarizes the application of high-precision and in situ characterization devices in the field of HEO MNMs, offering robust support for related research. Finally, a brief introduction to the main applications of HEO MNMs is provided, emphasizing their key performances. This review offers valuable guidance for future research on HEO MNMs, outlining critical issues and challenges in the current field.

Fiber Actuators Based on Reversible Thermal Responsive Liquid Crystal Elastomer.

Soft actuators inspired by the movement of organisms have attracted extensive attention in the fields of soft robotics, electronic skin, artificial intelligence, and healthcare due to their excellent adaptability and operational safety. Liquid crystal elastomer fiber actuators (LCEFAs) are considered as one of the most promising soft actuators since they can provide reversible linear motion and are easily integrated or woven into complex structures to perform pre-programmed movements such as stretching, rotating, bending, and expanding. The research on LCEFAs mainly focuses on controllable preparation, structural design, and functional applications. This review, for the first time, provides a comprehensive and systematic review of recent advances in this important field by focusing on reversible thermal response LCEFAs. First, the thermal driving mechanism, and direct and indirect heating strategies of LCEFAs are systematically summarized and analyzed. Then, the fabrication methods and functional applications of LCEFAs are summarized and discussed. Finally, the challenges and technical difficulties that may hinder the performance improvement and large-scale production of LCEFAs are proposed, and the development opportunities of LCEFAs are prospected.

Fabrication of N-halamine/MWPPy-ZnO hybrids based cellulose nanofibril composite films with improved UV-protective, antibacterial, and biofilm control functions.

The design and fabrication of synergistic hybrid antibacterial materials is a promising approach for achieving effective sterilization while compensating for the deficiency of a single component. Despite being highly effective biocidal components, the poor UV light stability of some N-halamines limits their applications. This study was conducted to address this issue by the rational integration of cyclic N-halamine precursor (PGHAPA) with microwaved zinc oxide (MWPPy-ZnO) nanoparticles via covalent bonds and the preparation of cellulose nanofibrils based antibacterial composite films after chlorination (CNF/MWPPy-ZnO-PGHAPA-Cl). The proposed films offered tight lamellar structure, considerable thermal stability and better mechanical properties. The results from the FT-IR and XPS experiments provided the evidence of chemical reactions among the PGHAPA, MWPPy-ZnO, and CNF film. Notably, the CNF/MWPPy-ZnO-PGHAPA-Cl films showed improved UV stability with a chlorine content of up to 0.16 % after 24 h of irradiation, which was much greater than that of the CNF/PGHAPA-Cl films. Furthermore, the CNF/MWPPy-ZnO-PGHAPA-Cl films displayed rapid bactericidal activity, inactivating all the contacted Staphylococcus aureus and Escherichia coli O157:H7 strains within 5 min, along with prominent biofilm disruption, indicating great potential for daily food packaging applications.

A Nile red dye cathode with an asymmetric redox unit for lithium organic batteries.

A Nile red (NR) dye cathode with an asymmetric redox structure of para CN and CO bonds was developed for use in an efficient lithium organic battery with a good capacity of 125 mA h g-1 and two visible discharge/charge voltage plateaus (≈2.0 V and ≈1.7 V). The NR cathode demonstrated the advantages of employing cost-effective dyes to achieve multigradient voltage platform regulation.

A facile restructuring of 3D high water absorption aerogels from methoxy polyethylene glycol­polycaprolactone (mPEG­PCL) nanofibers.

High water absorption aerogels with three-dimensional porous structures and high specific surface areas have been fabricated from methoxy polyethylene glycol­polycaprolactone block copolymer (mPEG­PCL) via a facile approach by electrospinning, mechanical homogeneous shearing and dispersing short fibers in the water, freeze-drying, and heat crosslinking. The three-dimensional nanofiber aerogels (TNAs) exhibit continuous porous structures which are restructured with crisscrossed and dispersed nanofibers. The aerogel displays a low density (36 ±â€¯3 mg/cm3), a high specific surface area (230 m2/g), a high pore volume (5.9 cm3/g), a high porosity of 85% as well as an average pore diameter (1.12 µm). The as-made mPEG-PCL TNAs deliver a high average water-absorption capacity of 24.11 g/g and a good retention ability owing to the three-dimensional porous structures and large micropores population. The water absorption could still reach approximately 25 g/g after 10 compression cycles of TNAs. The average dehydration weight loss of 3.1% demonstrates that the materials are hardly soluble in the water, and the structural characteristic would not be changed after water adsorption. The antimicrobial activity against the bacteria Staphylococcus aureus and Escherichia coli are assessed that the TNAs are suitable carriers of antimicrobial agents. Moreover, as showed by cytotoxic tests, the TNAs are neglectable toxic, which are suitable for applications in environmental bioengineering. Based on the high water absorption and biocompatibility, the TNAs could be suitable candidates for health care materials and medical products.

Direct N-H/α,α,ß,ß-C(sp3)-H functionalization of piperidine via an azomethine ylide route: synthesis of spirooxindoles bearing 3-substituted oxindoles.

A protocol for the direct functionalization of N-H/α,α,ß,ß-C(sp3)-H of piperidine without any metal or external oxidants is reported. This reaction is promoted by 4-(trifluoromethyl)benzoic acid via an azomethine ylide intermediate. This is a simple method for the synthesis of spirooxindoles bearing 3-substituted oxindole moieties.

Correction: Direct N-H/α,α,ß,ß-C(sp3)-H functionalization of piperidine via an azomethine ylide route: synthesis of spirooxindoles bearing 3-substituted oxindoles.

Correction for 'Direct N-H/α,α,ß,ß-C(sp3)-H functionalization of piperidine via an azomethine ylide route: synthesis of spirooxindoles bearing 3-substituted oxindoles' by Yanlong Du et al., Chem. Commun., 2017, 53, 1684-1687.

Solvent-Controlled Switchable Domino Reactions of MBH Carbonate: Synthesis of Benzothiophene Fused α-Pyran, 2,3-Dihydrooxepine, and Oxatricyclodecene Derivatives.

Solvent-controlled switchable domino reactions between 2-alkylidenebenzothiophene-3(2H)-ones and Morita-Baylis-Hillamn (MBH) carbonate were developed. All domino reactions exhibited excellent regioselectivity, producing a broad spectrum of benzothiophene-fused α-pyran, 2,3-dihydrooxepine, and oxatricyclodecene derivatives. Furthermore, [4 + 2], [4 + 3], and related domino reactions from identical substrates can be controlled.

NaH promoted [4+3] annulation of crotonate-derived sulfur ylides with thioaurones: synthesis of 2,5-dihydrobenzo[4,5]thieno[3,2-b]oxepines.

The [4+3] annulation reaction of crotonate-derived sulfur ylides with thioaurones has, for the first time, been reported using NaH as the base. A diverse array of 2,5-dihydrobenzo[4,5]thieno[3,2-b]oxepines is obtained in good to excellent yields. The proposed mechanism is investigated and supported by DFT calculations.