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151.
Jacobus C. Duburg Kobra Azizi Sren Primdahl Hans Aage Hjuler Elena Zanzola Thomas J. Schmidt Lorenz Gubler 《Molecules (Basel, Switzerland)》2021,26(6)
Currently, energy storage technologies are becoming essential in the transition of replacing fossil fuels with more renewable electricity production means. Among storage technologies, redox flow batteries (RFBs) can represent a valid option due to their unique characteristic of decoupling energy storage from power output. To push RFBs further into the market, it is essential to include low-cost materials such as new generation membranes with low ohmic resistance, high transport selectivity, and long durability. This work proposes a composite membrane for vanadium RFBs and a method of preparation. The membrane was prepared starting from two polymers, meta-polybenzimidazole (6 μm) and porous polypropylene (30 μm), through a gluing approach by hot-pressing. In a vanadium RFB, the composite membrane exhibited a high energy efficiency (~84%) and discharge capacity (~90%) with a 99% capacity retention over 90 cycles at 120 mA·cm−2, exceeding commercial Nafion® NR212 (~82% efficiency, capacity drop from 90% to 40%) and Fumasep® FAP-450 (~76% efficiency, capacity drop from 80 to 65%). 相似文献
152.
Jana ic
labur Marko Brajer Sandra Voa Ante Gali Sanja Radman Suzana Rimac-Brn
i Qiang Xia Zhenzhou Zhu Nabil Grimi Francisco J. Barba Nataa Hulak 《Molecules (Basel, Switzerland)》2021,26(7)
Spices are a popular food of plant origin, rich in various phytochemicals and recognized for their numerous properties. The aim of the study was to evaluate the antioxidant and antimicrobial activity, as well as the content of specialized metabolites, of aqueous extracts of three spice species––garlic (Allium sativum L.), ginger (Zingiber officinalle L.) and turmeric (Curcuma longa L.)––prepared by green extraction methods. Ultrasound treatment increased the chromaticity parameter b value of turmeric and ginger extracts, thus indicating a higher yellow color predominantly due to curcuminoids characteristic of these species. Ultrasound-assisted extraction significantly increased the content of total soluble solids, phenolic compounds, total carotenoids and vitamin C. The temperature of the system was also an important factor, with the highest (70 °C) conditions in ultrasound-assisted extraction having a positive effect on thermolabile compounds (vitamin C, phenolics, total carotenoids). For example, turmeric extract treated with ultrasound at 70 °C had up to a 67% higher vitamin C content and a 69.4% higher total carotenoid content compared to samples treated conventionally at the same temperature, while ginger extracts had up to 40% higher total phenols. All different concentrations of spice extracts were not sufficient for complete inhibition of pathogenic bacterial strains of Salmonella, L. monocytogenes and S. aureus; however, only garlic extracts had an effect on slowing down the growth and number of L. monocytogenes colonies. Spice extracts obtained by ultrasonic treatment contained a significantly higher level of bioactive compounds and antioxidant capacity, suggesting that the extracts obtained have significant nutritional potential and thus a significant possibility for phytotherapeutic uses. 相似文献
153.
ZHOU Xi LAI Yangyang WU Xiangjiang CHEN Zhongxue ZHONG Faping Al Xinping YANG Hanxi CAO Yuliang 《高等学校化学研究》2021,37(2):274-279
Sodium-ion batteries(SIBs)are promising for grid-scale energy storage applications due to the natural abundance and low cost of sodium.Among various Na insertion cathode materials,Na0.44MnO2 has attracted the most attention because of its cost effectiveness and structural stability.However,the low initial charge capacity for Na-poor Na0.44MnO2 hinders its practical applications.Herein,we developed a facile chemical presodiated method using sodiated biphenly to transform Na-poor Na0.44MnO2 into Na-rich Na0.66MnO2.After presodiation,the initial charge capacity of Na0.44MnO2 is greatly enhanced from 56.5 mA·h/g to 115.7 mA·h/g at 0.1 C(1 C=121 mA/g)and the excellent cycling stability(the capacity retention of 94.1%over 200 cycles at 2 C)is achieved.This presodiation strategy would open a new avenue for promoting the practical applications of Na-poor cathode materials in sodium-ion batteries. 相似文献
154.
《Arabian Journal of Chemistry》2021,14(11):103421
Processing of Carapa guianensis seeds to obtain oil on an industrial scale generates a significant amount of by-product, approximately 66% w/w, which is called cake and is a potential source of biomolecules, including simple phenolic structures. For this reason, studies were carried out on the chemical profiles of hydrolyzed extract from this agro-industrial by-product through High Performance Thin-Layer Chromatography (HPTLC) and Gas Chromatography coupled to Mass Spectrometry (GC–MS). These techniques were used to detect metabolic classes and/or groups, and to identify, for the first time, thirteen simple phenolic acids in this by-product. The sample antioxidant capacity was determined by methods of 2,2-diphenyl-1-picrylhydrazyl (DPPH)and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+) radicals direct sequestration. The hydrolyzed fraction showed a total of 63.47% in the relative abundance of the total of compounds, standing out: p-hydroxybenzoic acid (39.19%) and protocatechuic acid (3,4-dihydroxybenzoic acid) (5.62%), both from hydroxybenzoic acids and 3-(3,4-dihydroxyphenyl)lactic acid, (7.76%) hydroxycinnamic acids derivatives. In these results, the fraction rich in simple phenolic acids was obtained, attributing the prominent behavior of this matrix antioxidant activity, expressed by (IC50: of 16.42 µg/mL and 6.52 µg/mL for DPPH and ABTS+ radicals, respectively). The research demonstrated an alternative to applicability that involves sustainability from agro-industrial. These techniques were used to detect metabolic classes and/or groups, and to identify, for the first time, thirteen simple phenolic acids in this by-product, generating a process capable of converting biomass into a bioproduct, consisting of bioactive compounds, in addition to adding value to the industrial chain. 相似文献
155.
156.
Single phase of ammonium tetramolybdate in the micro power form was prepared from polyphase ammonium paramolybdate. Its heat capacity from 14.25℃ to 120.12 ℃ was measured by drop method and the result is
Cp=0.3936+7.4047×10-4T+6.3543×10-3T-2(J•K-1•g-1) 相似文献
Cp=0.3936+7.4047×10-4T+6.3543×10-3T-2(J•K-1•g-1) 相似文献
157.
158.
Valeriy V. Bezrodnyi Sofia E. Mikhtaniuk Oleg V. Shavykin Igor M. Neelov Nadezhda N. Sheveleva Denis A. Markelov 《Molecules (Basel, Switzerland)》2021,26(21)
Novel peptide dendrimer with Lys-2His repeating units was recently synthesized, studied by NMR (Molecules, 2019, 24, 2481) and tested as a nanocontainer for siRNA delivery (Int. J. Mol. Sci., 2020, 21, 3138). Histidine amino acid residues were inserted in the spacers of this dendrimer. Increase of their charge with a pH decrease turns a surface-charged dendrimer into a volume-charged one and should change all properties. In this paper, the molecular dynamics simulation method was applied to compare the properties of the dendrimer in water with explicit counterions at two different pHs (at normal pH with neutral histidines and at low pH with fully protonated histidines) in a wide interval of temperatures. We obtained that the dendrimer at low pH has essentially larger size and size fluctuations. The electrostatic properties of the dendrimers are different but they are in good agreement with the theoretical soft sphere model and practically do not depend on temperature. We have shown that the effect of pairing of side imidazole groups is much stronger in the dendrimer with neutral histidines than in the dendrimer with protonated histidines. We also demonstrated that the capacity of a nanocontainer based on this dendrimer with protonated histidines is significantly larger than that of a nanocontainer with neutral histidines. 相似文献
159.
I. Neelakanta Reddy Bhargav Akkinepally Venkatesu Manjunath Gaddam Neelima Mogalahalli V. Reddy Jaesool Shim 《Molecules (Basel, Switzerland)》2021,26(23)
In this study, the facile synthesis of SnO2 quantum dot (QD)-garnished V2O5 nanobelts exhibiting significantly enhanced reversible capacity and outstanding cyclic stability for Li+ storage was achieved. Electrochemical impedance analysis revealed strong charge transfer kinetics related to that of V2O5 nanobelts. The SnO2 QD-garnished V2O5 nanobelts exhibited the highest discharge capacity of ca. 760 mAhg−1 at a density of 441 mAg−1 between the voltage ranges of 0.0 to 3.0 V, while the pristine V2O5 nanobelts samples recorded a discharge capacity of ca. 403 mAhg−1. The high capacity of QD-garnished nanobelts was achieved as an outcome of their huge surface area of 50.49 m2g−1 and improved electronic conductivity. Therefore, the as-presented SnO2 QD-garnished V2O5 nanobelts synthesis strategy could produce an ideal material for application in high-performance Li-ion batteries. 相似文献
160.
Szymon Poliski Sylwia Kowalska Patrycja Topka Aleksandra Szydowska-Czerniak 《Molecules (Basel, Switzerland)》2021,26(18)
In this study, dark chocolates (DCh) containing zinc lactate (ZnL) were enriched with extracts from elderberries (EFrE), elderflowers (EFlE), and chokeberries (ChFrE) to improve their functional properties. Both dried plant extracts and chocolates were analyzed for antioxidant capacity (AC) using four different analytical methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), and ferric-reducing antioxidant power (FRAP), while total phenolic content (TPC) was determined by Folin–Ciocalteu (F–C) assay. An increase in antioxidant properties of fortified chocolates was found, and the bioaccessibility of their antioxidants was evaluated. The highest AC and TPC were found in ChFrE and chocolate with chokeberries (DCh + ChFrE) before and after simulated in vitro digestion. Bioaccessibility studies indicated that during the simulated digestion the AC of all chocolates reduced significantly, whereas insignificant differences in TPC results were observed between chemical and physiological extracts. Moreover, the influence of plant extracts on physicochemical parameters such as moisture content (MC), fat content (FC), and viscosity of chocolates was estimated. Furthermore, scanning electron microscopy with dispersive energy spectroscopy (SEM-EDS) was used to analyze surface properties and differences in the chemical composition of chocolates without and with additives. 相似文献