Ultrafast Synthesis of Graphene-Embedded Cyclodextrin-Metal-Organic Framework for Supramolecular Selective Absorbency and Supercapacitor Performance.

Limited by preparation time and ligand solubility, synthetic protocols for cyclodextrin-based metal-organic framework (CD-MOF), as well as subsequent derived materials with improved stability and properties, still remains a challenge. Herein, an ultrafast, environmentally friendly, and cost-effective microwave method is proposed, which is induced by graphene oxide (GO) to design CD-MOF/GOs. This applicable technique can control the crystal size of CD-MOFs from macro- to nanocrystals. CD-MOF/GOs are investigated as a new type of supramolecular adsorbent. It can selectively adsorb the dye molecule methylene green (MG) owing to the synergistic effect between the hydrophobic nanocavity of CDs, and the abundant O-containing functional groups of GO in the composites. Following high temperature calcination, the resulting N, S co-doped porous carbons derived from CD-MOF/GOs exhibit a high capacitance of 501 F g-1 at 0.5 A g-1 , as well as stable cycling stability with 90.1% capacity retention after 5000 cycles. The porous carbon exhibits good electrochemical performance due to its porous surface containing numerous electrochemically active sites after dye adsorption and carbonization. The design strategy by supramolecular incorporating a variety of active molecules into CD-MOFs optimizes the properties of their derived materials, furthering development toward the fabrication of zeitgeisty and high-performance energy storage devices.

Rapid Synthesis of Oxygen-Enriched Porous Carbon through a Microwave Method and Its Application in Supercapacitors.

In this study, a strategy for the rapid and simple preparation of porous carbon (PC) using the microwave method was proposed. Oxygen-rich PC was synthesized by microwave irradiation in air, where potassium citrate and ZnCl2 served as the carbon source and microwave absorber, respectively. ZnCl2 achieves microwave absorption through dipole rotation, which uses ion conduction to convert heat energy in the reaction system. In addition, potassium salt etching improved the porosity of PCs. The PC prepared under optimal conditions had a large specific surface area (902 m2·g-1) and exhibited a significant specific capacitance (380 F·g-1) in the three-electrode system at 1 A·g-1. The energy and power densities of the assembled symmetrical supercapacitor device based on PC-375W-0.4 were 32.7 W·h·kg-1 and 0.65 kW·kg-1, respectively, at a current density of 1 A·g-1. Even after 5000 cycles at 5 A·g-1 current density, the excellent cycle life retained 94% of its initial capacitance.

Anti-Inflammatory Activity of Velvet Bean (Mucuna pruriens) Substances in LPS-Stimulated RAW 264.7 Macrophages.

In this study, Mucuna pruriens extracts were used to verify their application as a natural-based raw material with anti-inflammatory function. A nitric oxide inhibition activity assay showed that M. pruriens extracted with hot water (MW), M. pruriens extracted with 70% ethanol (ME), and M. pruriens extracted with 70% acetone (MA) presented NO inhibition activity; among them, MW and ME demonstrated the best activity and were selected for Western blot analysis. After identifying the expression patterns of inflammation-related proteins, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), c-jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB), through Western blots, both MW and ME showed inhibition patterns. As a result of analyzing L-DOPA contained in M. pruriens through ultra-performance liquid chromatography (UPLC), high L-DOPA content was detected in MW, ME, and MA. Therefore, it can be concluded that M. pruriens extracts have the potential for use as an anti-inflammatory material.

Design strategies for adhesive hydrogels with natural antibacterial agents as wound dressings: Status and trends.

The wound healing process is usually susceptible to different bacterial infections due to the complex physiological environment, which significantly impairs wound healing. The topical application of antibiotics is not desirable for wound healing because the excessive use of antibiotics might cause bacteria to develop resistance and even the production of super bacteria, posing significant harm to human well-being. Wound dressings based on adhesive, biocompatible, and multi-functional hydrogels with natural antibacterial agents have been widely recognized as effective wound treatments. Hydrogels, which are three-dimensional (3D) polymer networks cross-linked through physical interactions or covalent bonds, are promising for topical antibacterial applications because of their excellent adhesion, antibacterial properties, and biocompatibility. To further improve the healing performance of hydrogels, various modification methods have been developed with superior biocompatibility, antibacterial activity, mechanical properties, and wound repair capabilities. This review summarizes hundreds of typical studies on various ingredients, preparation methods, antibacterial mechanisms, and internal antibacterial factors to understand adhesive hydrogels with natural antibacterial agents for wound dressings. Additionally, we provide prospects for adhesive and antibacterial hydrogels in biomedical applications and clinical research.

Facile and scaleable transformation of Cu nanoparticles into high aspect ratio Cu oxide nanowires in methanol.

In this work, a facile synthetic route for the preparation of high aspect ratio Cu oxide nanowires is reported. The preparation of the Cu oxide nanowires begins with the generation of pure Cu nanoparticles by inert gas condensation (IGC) method, follows by dispersing the obtained nanoparticles in methanol with the aid of ultrasonication. The mixture is stored at different temperature for the transformation from Cu nanoparticle to Cu oxide nanowires. The influences of the kind of solution, the ratio of methanol to Cu nanoparticle, dispersion time and temperature towards the generation of Cu oxide nanowires are studied in detail. Scanning electron microscopy studies indicate that high aspect ratio Cu oxide nanowires with diameter of a few tens of nanometers and length up to several tens of micrometers could be obtained under proper conditions. The mechanism for the transformation of Cu nanoparticles to Cu oxide nanowires is also investigated.

Metallic and porous Ti nanorod arrays for visible-IR light absorption and dendrite-free stable lithium-metal batteries.

It is still a challenging task to prepare highly porous nanorod arrays of metals formed on substrates for optical and energy storage applications. Herein, we demonstrate the design and synthesis of black color, metallic and highly porous Ti nanorod arrays as novel current collectors for dendrite-free and highly stable Li-metal anodes. The high porosity of metallic nanorod arrays provides numerous heterogeneous nucleation sites and huge contact area and large space for the accommodation of Li metal. The conductive metallic Ti nanorod arrays enhance electrode integration. Effectively, it eliminates formation Li dendrites and demonstrates superior cycling stability over 300 cycles. Additionally, the unique porous structures of the nanorod arrays can decrease the amplitude of forced vibration in narrow space leading to light absorption. Interestingly, the metal is black instead of metallic color. The black metallic nanorod arrays can absorb more than 96% of both visible and infra-red lights. This black color metallic porous nanorod arrays may find additional applications in aerospace, energy, biomedical, defence, and chemical industries.