Low-Cost Aqueous Electrolyte with MBA Additives for Uniform and Stable Zinc Deposition.

Aqueous zinc ion batteries (AZIBs) are attracting increasing research interest due to their intrinsic safety, low cost, and scalability. However, the issues including hydrogen evolution, interface corrosion, and zinc dendrites at anodes have seriously limited the development of aqueous zinc ion batteries. Here, N,N-methylenebis(acrylamide) (MBA) additives with -CONH- groups are introduced to form hydrogen bonds with water and suppress H2O activity, inhibiting the occurrence of hydrogen evolution and corrosion reactions at the interface. In situ optical microscopy demonstrates that the MBA additive promotes the uniform deposition of Zn2+ and then suppresses the dendrite growth on the zinc anode. Therefore, Zn//Ti asymmetric batteries demonstrate a high plating/stripping efficiency of 99.5%, while Zn//Zn symmetric batteries display an excellent cycle stability for more than 1000 h. The Zn//MnO2 full cells exhibit remarkable cycling stability for 700 cycles in aqueous electrolytes with MBA additives. The additive engineering via MBA achieved the dendrite-free Zn anodes and stable full batteries, which is favorable for advanced AZIBs in practical applications.

Nitrogen and Sulfur Co-Doped Hierarchically Porous Carbon Nanotubes for Fast Potassium Ion Storage.

Exploration of advanced carbon anode material is the key to circumventing the sluggish kinetics and poor rate capability for potassium ion storage. Herein, a synergistic synthetic strategy of engineering both surface and structure is adopted to design N, S co-doped carbon nanotubes (NS-CNTs). The as-designed NS-CNTs exhibit unique features of defective carbon surface, hollow tubular channel, and enlarged interlayer space. These features significantly contribute to a large potassium storage capacity of 307 mA h g-1 at 1 A g-1 and a remarkable rate performance with a capacity of 151 mA h g-1 even at 5 A g-1 . Furthermore, an excellent cyclability with 98% capacity retention after 500 cycles at 2 A g-1 is also achieved. Systematic analysis by in situ Raman spectroscopy and ex situ TEM demonstrates the structural stability and reversibility in the charge-discharge process. Although the kinetics studies reveal the capacitive-dominated process for potassium storage, density functional theory calculations provide evidence that N, S co-doping contributes to expanding the interlayer space to promote the K-ion insertion, improving the electronic conductivity, and providing ample defective sites to favor the K-ion adsorption.

Enzymatically modified quinoa starch-based Pickering emulsion: Effect of enzymolysis and emulsifying conditions.

Both the effects of enzymolysis condition on the microstructures and emulsifying property of enzymatic modified quinoa starch (EMQS) and the effects of emulsion formulation on the EMQS based emulsions were investigated. The emulsifying capacity (EC) and stability (ES) of EMQS were positive correlated with enzyme amount (0-2.4 % w/wstarch). The particle sizes of EMQS decreased and its hydrophobicity increased with increasing enzyme amount (0-2.4 % w/wstarch), which were the main reasons for the increasing emulsifying performance of EMQS. With the increasing starch concentration, the EC of the EMQS increased, the oil droplet size of the emulsion decreased. With the oil/water ratios ranging from 1:9 to 6:4, the emulsification index (EI) and oil droplet size of the emulsion increased. EMQS based emulsion had a relatively good stability in the pH range of 2-10. This study lays the foundation for the application of EMQS as a stable clean-label Pickering emulsifier.

Pickering emulsifiers based on enzymatically modified quinoa starches: Preparation, microstructures, hydrophilic property and emulsifying property.

Quinoa starch was developed as a new kind of Pickering emulsifier by enzymatic modification. The morphological structure, crystalline structure, lamellar structure, fractal structure, particle size distribution, contact angle, emulsion index (EI), and emulsion micromorphology were studied to explore the relationship between structure characteristics, hydrophilic property, and emulsifying properties of enzymatically modified (EM) quinoa starches. With the increasing enzymatic hydrolysis time in the test range of 0-9 h, particle size of EM quinoa starch decreased, and the broken starch and contact angle of EM quinoa starch increased; the EI value of emulsions with EM quinoa starch increased, and the oil droplet size of emulsions with EM quinoa starch decreased. It suggested that both the smallest particle size and the closest extent of the contact angle to 90° derived the best emulsifying property of EM-9. The EM quinoa starch had higher emulsifying capacity at higher oil volume fraction (Φ) (50%) than at lower Φ (20%), proving that the EM starch has potential to be used as Pickering emulsifiers in higher oil products, such as salad dressing.

Fast energy storage performance of CoFe2O4/CNTs hybrid aerogels for potassium ion battery.

We report CoFe2O4 and carbon nanotubes hybrid aerogels as a novel anode material for potassium ion batteries (KIBs). The synthetic route take the advantage of marine biobased materials as the precursor and facilely produce large-scale production of hybrid CoFe2O4 and carbon nanotubes aerogels as the advanced anode. The hybrid aerogels deliver a remarkable capacity of 180 mAh g-1 with high stability over 200 cycles at a current density of 0.1 A g-1. The high rate charge/discharge reveals a relatively high capacity of 83 mAh g-1 even at the current density of 1.0 A g-1. In-situ XRD investigations reveal the phase evolution during charge/discharge, demonstrating the high stability of hybrid aerogels for the potassium intercalation/extraction. The high specific surface area and large numbers of mesopores with more active sites can benefit the effective transmission of electrons and K ions, leading to an improved specific capacity and cycle stability.

Effect of different ionic liquids acting as plasticizers on the multi-scale structures and physical properties of hydroxypropyl methylcellulose/monosodium phosphate photophobic film.

Different ionic liquid (IL)s were added to hydroxypropyl methylcellulose /monosodium phosphate (HPMC/MSP) photophobic film to improve its ductility, and their effects on its multi-scale structures and physical properties were studied. After adding these ILs, smoothness of the fractal structure, tensile strength, modulus of the film did not change obviously, while the crystallinity, the number of holes, and elongation increased, the hole size and Tg decreased. Compared to films with other ILs, the film with 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) showed the largest elongation and crystallinity, the smallest hole size, the least holes, and highest whiteness. The film with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) showed the largest water content and the lowest Tg. The increased elongation proved that all these ILs could improve the ductility of the film, among which, [EMIM]BF4 had the strongest plasticizing effect.

Smart configuration of cobalt hexacyanoferrate assembled on carbon fiber cloths for fast aqueous flexible sodium ion pseudocapacitor.

Aqueous rechargeable batteries (ARBs) have the advantages of low cost, high safety and sustainable environmental friendliness. However, the key challenge for ARBs is the narrow electrochemical stability window of the water, undoubtedly leading to the low output voltage, the underachieved capacity and a low energy density. Prussian blues and their analogues have attracted great research interest for energy storage due to the advantages of facile synthesis, versatile categories and tunable three dimensional frameworks. Herein a flexible integrated potassium cobalt hexacyano ferrates (Co-HCF) on carbon fiber clothes (CFCs) were designed through a feasible route combining the controllable electrochemical deposition and the efficient co-precipitation process. The Co-HCF@CFCs demonstrate an excellent sodium ion storage with a high reversible capacity of 91 mAh g-1 at 1 A g-1 and 55 mAh g-1 at 10 A g-1 in aqueous electrolytes. The long cycling stability at the high current demonstrate the excellent structure stability of the Co-HCF@CFCs. Analysis on the rate Cyclic voltammograms (CV) profiles reveal the fast electrochemical kinetics with the capacitive controlled process, while galvanostatic intermittent titration technique (GITT) tests fast diffusion coefficient related with the sodium ions intercalation/deintercalation in the Co-HCF@CFCs. In addition, the flexible Co-CHF@CFCs also demonstrate excellent performance for quasi-solid-state ARBs even at the high bending angles. The high quality Co-HCF@CFCs with advantage of high rate capability and excellent reversible capacity make them a promising candidate for high performance ARBs.

Lithium Titanate Cuboid Arrays Grown on Carbon Fiber Cloth for High-Rate Flexible Lithium-Ion Batteries.

High-rate performance flexible lithium-ion batteries are desirable for the realization of wearable electronics. The flexibility of the electrode in the battery is a key requirement for this technology. In the present work, spinel lithium titanate (Li4 Ti5 O12 , LTO) cuboid arrays are grown on flexible carbon fiber cloth (CFC) to fabricate a binder-free composite electrode (LTO@CFC) for flexible lithium-ion batteries. Experimental results show that the LTO@CFC electrode exhibits a remarkably high-rate performance with a capacity of 105.8 mAh g-1 at 50C and an excellent electrochemical stability against cycling (only 2.2% capacity loss after 1000 cycles at 10C). A flexible full cell fabricated with the LTO@CFC as the anode and LiNi0.5 Mn1.5 O4 coated on Al foil as the cathode displays a reversible capacity of 109.1 mAh g-1 at 10C, an excellent stability against cycling and a great mechanical stability against bending. The observed high-rate performance of the LTO@CFC electrode is due to its unique corn-like architecture with LTO cuboid arrays (corn kernels) grown on CFC (corn cob). This work presents a new approach to preparing LTO-based composite electrodes with an architecture favorable for ion and electron transport for flexible energy storage devices.

N-Doped amorphous MoSx for the hydrogen evolution reaction.

Herein, the functions of a N dopant in crystalline MoS2 catalysts during the electrochemical hydrogen evolution reaction (HER) were reported via a combined experimental and first-principles approach. However, studies on the N doping of amorphous MoSx, which is a more active catalyst, have not been reported to date. In this study, via a simple method, we fabricated N-doped amorphous MoSx for the first time and studied the correlations between the N dopant and the HER performance. Via X-ray photoelectron spectroscopy and theoretical formation energy calculations, we have found that a N dopant in basal plane S2- plays a very important role in the improvement of the HER performance and remains stable during this dynamic transformation process. A N dopant in basal plane S2- can increase the number of active sites toward the HER and enhance the conductivity of the catalysts as well as a N dopant in c-MoS2. In addition to this, the first-principles calculations further suggested that a N dopant in basal plane S2- could improve the activity of unsaturated MoV active sites by bringing its hydrogen adsorption free energy closer to zero. As a result, N-doped amorphous MoSx possesses an overpotential of 143 mV at 10 mA cm-2 and a Tafel slope of 57 mV dec-1, much better than those of a-MoSx. These results provide useful insights for the future development of nonmetal-doped MoSx catalysts in the HER.

Effect of plasticizers on microstructure, compatibility and mechanical property of hydroxypropyl methylcellulose/hydroxypropyl starch blends.

Polymer film blends of hydroxypropyl methylcellulose (HPMC) and hydroxypropyl starch (HPS) were produced with an incorporation of three different plasticizers, including polyethylene glycol (PEG), glycerol and 1, 2-propylene glycol (PG) respectively, and the influence of these plasticizers were compared and studied by X-ray Diffraction (XRD), small angel X-ray Scattering (SAXS), optical microscope and dynamic mechanical analysis (DMA). Results showed that multi-scale structure of the blends were greatly affected by the plasticizers and therefore caused significant changes in mechanical properties. In the course, blends with glycerol presented lamellar structure rather than self-similar structure. Moreover, crystalline degree was increased with an order of glycerol > PEG > PG, whereas the compactness of amorphous region of all samples was decreased by PEG and PG.

Nontopotactic Reaction in Highly Reversible Sodium Storage of Ultrathin Co9 Se8 /rGO Hybrid Nanosheets.

Transition metal chalcogenide with tailored nanosheet architectures with reduced graphene oxide (rGO) for high performance electrochemical sodium ion batteries (SIBs) are presented. Via one-step oriented attachment growth, a facile synthesis of Co9 Se8 nanosheets anchored on rGO matrix nanocomposites is demonstrated. As effective anode materials of SIBs, Co9 Se8 /rGO nanocomposites can deliver a highly reversible capacity of 406 mA h g-1 at a current density of 50 mA g-1 with long cycle stability. It can also deliver a high specific capacity of 295 mA h g-1 at a high current density of 5 A g-1 indicating its high rate capability. Furthermore, ex situ transmission electron microscopy observations provide insight into the reaction path of nontopotactic conversion in the hybrid anode, revealing the highly reversible conversion directly between the hybrid Co9 Se8 /rGO and Co nanoparticles/Na2 Se matrix during the sodiation/desodiation process. In addition, it is experimentally demonstrated that rGO plays significant roles in both controllable growth and electrochemical conversion processes, which can not only modulate the morphology of the product but also tune the sodium storage performance. The investigation on hybrid Co9 Se8 /rGO nanosheets as SIBs anode may shed light on designing new metal chalcogenide materials for high energy storage system.

Naturally active oligostilbenes.

Many naturally occurring oligostilbenes have drawn considerable attention because of their intricate structures and diverse biological activities. In recent years, oligostilbene bioactivities have become a popular research topic worldwide. Although these bioactivities are known to be extensive and several summaries on the activities of the compounds have been published, a comprehensive and systematic summary on active oligostilbenes is unavailable. From January 2005 to December 2013, a large number of active oligostilbenes and corresponding new bioactivities were reported in the literature. This review mainly focuses on the diverse bioactivities of oligostilbenes with various backbones.

Potassium Hexacyanoferrate (III)-Catalyzed Dimerization of Hydroxystilbene: Biomimetic Synthesis of Indane Stilbene Dimers.

Using potassium hexacyanoferrate (III)-sodium acetate as oxidant, the oxidative coupling reaction of isorhapontigenin and resveratrol in aqueous acetone resulted in the isolation of three new indane dimers 4, 6, and 7, together with six known stilbene dimers. Indane dimer 5 was obtained for the first time by direct transformation from isorhapontigenin. The structures and relative configurations of the dimers were elucidated using spectral analysis, and their possible formation mechanisms were discussed. The results indicate that this reaction could be used as a convenient method for the semi-synthesis of indane dimers because of the mild conditions and simple reaction products.

Pseudocapacitance of MXene nanosheets for high-power sodium-ion hybrid capacitors.

High-power Na-ion batteries have tremendous potential in various large-scale applications. However, conventional charge storage through ion intercalation or double-layer formation cannot satisfy the requirements of such applications owing to the slow kinetics of ion intercalation and the small capacitance of the double layer. The present work demonstrates that the pseudocapacitance of the nanosheet compound MXene Ti2C achieves a higher specific capacity relative to double-layer capacitor electrodes and a higher rate capability relative to ion intercalation electrodes. By utilizing the pseudocapacitance as a negative electrode, the prototype Na-ion full cell consisting of an alluaudite Na2Fe2(SO4)3 positive electrode and an MXene Ti2C negative electrode operates at a relatively high voltage of 2.4 V and delivers 90 and 40 mAh g(-1) at 1.0 and 5.0 A g(-1) (based on the weight of the negative electrode), respectively, which are not attainable by conventional electrochemical energy storage systems.

Iron-oxalato framework with one-dimensional open channels for electrochemical sodium-ion intercalation.

Discovery of a new class of ion intercalation compounds is highly desirable due to its relevance to various electrochemical devices, such as batteries. Herein, we present a new iron-oxalato open framework, which showed reversible Na(+) intercalation/extraction. The hydrothermally synthesized K4Na2[Fe(C2O4)2]3⋅2 H2O possesses one-dimensional open channels in the oxalato-bridged network, providing ion accessibility up to two Na(+) per the formula unit. The detailed studies on the structural and electronic states revealed that the framework exhibited a solid solution state almost entirely during Na(+) intercalation/extraction associated with the reversible redox of Fe. The present work demonstrates possibilities of the oxalato frameworks as tunable and robust ion intercalation electrode materials for various device applications.

Chemical constituents from the linseed meal.

One megastigmane derivative 1, one methyl jasmonate glycoside derivative 2, and two C-28 steroids with 3ß,5ß-cis-dihydroxyl conformation 3 and 4, together with eight known compounds 5-12 were isolated from the 70% ethanol extract of linseed meal (Linum usitatissimum L). Structures of 1-4 were elucidated by spectroscopic methods including NMR, HRESIMS, and Mo2(OAc)4-induced CD. The absolute configuration of 1 and 3 was determined by observing their induced circular dichroism after addition of Mo2(OAc)4 in DMSO. The absolute configuration of 2 was determined by NOESY experiment together with conformational analysis. The structure of 4a was corrected as 4 by an extensive analysis of its 1D and 2D NMR, in combination with the Mo2(OAc)4-induced CD in DMSO. The effect of all the isolates on nitric oxide (NO) generation by stimulated macrophages was evaluated, and none of them showed active.

Biomimetic synthesis of active isorhapontigenin dimers.

Synthetic isorhapontigenin was treated with several kinds of inorganic reagents and peroxidase so as to prepare active stilbene dimers. Among them, silver acetate in methanol gave two new isorhapontigenin dimers 4 and 5, together with four known natural stilbene dimers 2, 3, 6, and 7. Their structures and relative configurations were determined on the basis of spectral analysis, and their possible formation mechanisms were discussed, respectively. Compounds 2, 6, and 7 were artificially synthesized for the first time. All the products were evaluated for anti-inflammatory activities.

Effects of diamond-FET-based RNA aptamer sensing for detection of real sample of HIV-1 Tat protein.

Diamond is a promising material for merging solid-state and biological systems owing to its chemical stability, low background current, wide potential window and biocompatibility. The effects of surface charge density on human immunodeficiency virus type 1 Trans-activator transcription (HIV-1 Tat) protein binding have been investigated on a diamond field-effect transistor (FET) using ribonucleic acid (RNA) aptamers as a sensing element on a solid surface. A change in the gate potential of 91.6 mV was observed, whereby a shift in the negative direction was observed at a source-drain current of -8 µA in the presence of HIV-1 Tat protein bound to the RNA aptamers. Moreover, the reversible change in gate potential caused by the binding and regeneration cycles was very stable throughout cyclical detections. The stable immobilization is achieved via RNA aptamers covalently bonded to the carboxyl-terminated terephtalic acids on amine sites, thereby increasing the sensitivity of the HIV-1 Tat protein sensor. The reliable use of a real sample of HIV-1 Tat protein by an aptamer-FET was demonstrated for the first time, which showed the potential of diamond biointerfaces in clinical biosensor applications.

Effective surface functionalization of nanocrystalline diamond films by direct carboxylation for PDGF detection via aptasensor.

An aptasensor was designed on a nanocrystalline diamond (NCD) surface that combined with biological recognition elements, PDGF-binding aptamers, which inherently possess high affinity to PDGF-BB proteins. Functional components such as carboxylic acids (-COOH) and amines (-NH2) were directly introduced onto the NCD surface and used as probing units for immobilization of PDGF-binding aptamers. The surface coverage of different components on the NCD was analyzed by X-ray photoelectron spectroscopy (XPS) measurements, and the effects of various functionalizations on the NCD biosensor performance were investigated via fluorescence observations. The coverages of carboxyl and amine groups achieved were 12 and 23%, respectively, for the directly aminated and carboxylated NCD; however, the lower density of carboxyl groups on the functionalized surface did not deteriorate the performance of the COOH-NCD biosensor. Fluorescence investigations demonstrated comparable performance in sensitivity and selectivity for PDGF protein detection on COOH-NCD and NH2-NCD biosensors. Multiple regeneration tests clearly showed that the COOH-NCD biosensor as well as the NH2-NCD biosensor retained a high performance without exhibiting any noticeable degradation.