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关键词： Electrodes   Dissolution   Electrochemical cells   Electrolytes   Stability  

摘要： Given its abundance, costs and compatibility with Li, and relatively simple processing, a poly(ethylene oxide)-based solid electrolyte (PEO-based SE) is a reasonable benchmark SE system for solid-state lithium batteries. On the basis of recent pragmatic achievements in cell design and characterization methodology, the physicochemical properties of a PEO-based SE are effectively determined as a function of lithium bis-(trifluoromethyl sulfonyl)-imide (LiTFSI) salt concentration and correlated with the performance in LiNi0.6Mn0.2Co0.2O2 (NMC622)parallel to|lithium cells. Even though higher LiTFSI concentrations decrease the crystalline phases with a plasticizing effect and soften the SE membrane, the accompanying increase in amorphous phases enhances the Li+ diffusion coefficient, as galvanostatically obtained from the Sand equation. Both the increased diffusivity of Li+ and the overall amount of charge carriers lead to improved ionic conductivities with a higher LiTFSI concentration, particularly below the melting point (T-m < 60 degrees C). In terms of anodic behavior, neither SE decomposition nor Al current collector dissolution is relevantly affected by the LiTFSI concentration, revealing a bulk electrolyte stability of 4.6 V vs Li vertical bar Li+ and an Al dissolution tendency as low as in LiPF6-containing liquid organic electrolytes. Finally, at an operation temperature below T-m, a higher LiTFSI concentration sensitively increases the specific capacities and Coulombic efficiencies.

关键词： alpha-Synuclein   Dimer   Fibril   Familial Parkinson's disease   G51D mutation  

摘要： Fibril formation and aggregation of alpha-synuclein are important for the pathogenesis of neurodegenerative disorders including Parkinson's disease. In familial Parkinson's disease, the G51D mutation of alpha-synuclein causes severe symptoms and rapid progression. alpha-Synuclein, an intrinsically disordered protein, was shown to adopt an alpha-helical tetrameric state that resists fibrillation and aggregation. Here, we isolated the stable dimeric state of recombinant wild-type (WT) alpha-synuclein and G51D alpha-synuclein protein. Using circular dichroism spectroscopy, we determined that the alpha-synuclein dimer and monomer structures were unfolded. The WT alpha-synuclein dimer was more resistant to fibril formation than the monomer. However, the fibril formation rate of the G51D alpha-synuclein dimer was similar to that of the G51D alpha-synuclein monomer. The fibril morphology and properties of the G51D alpha-synuclein monomer were different from those of the WT alpha-synuclein monomer and dimer and G51D alpha-synuclein dimer. Additionally, G51D alpha-synuclein monomer fibrils were more cytotoxic than other fibrils. Our findings indicate that the structural differences between G51D alpha-synuclein monomer fibrils and other fibrils are critically responsible for its severe neurotoxicity in familial Parkinson's disease.

关键词： Asphalt concrete   Physical chemistry   Epoxy  

摘要： One of the failure mechanisms associated with asphalt paving layers, especially on steel deck bridges, is large permanent deformation, which adversely affects its long-term performance in service. Thus, epoxy resin was introduced in asphalt paving industry to tackle permanent deformation of asphalt mixtures due to its thermosetting nature. In this review, epoxy resin as a dominant component of the epoxy-asphalt composite system was first considered, followed by a discussion on its curing methods and curing mechanism. Furthermore, the physicochemical property and mechanical performance of epoxy asphalt and epoxy asphalt mixture were thoroughly examined. Crosslink density of epoxy asphalt dictates its viscosity and thus the allowable construction time. Phase separation and dispersion of asphalt particles in the epoxy matrix was observed for epoxy-asphalt composite, and it showed superior elastic behavior and deformation resistance capability when compared with conventional asphalt materials. Furthermore, epoxy asphalt mixture exhibited significantly higher compressive strength, much better rutting resistance, and superior durability and water resistance properties. However, its low-temperature cracking resistance was slightly compromised.

关键词： Physicochemical properties  

摘要： Since the first report by Yaghi's group in 2005, research enthusiasm has been increasingly raised to synthesize diverse crystalline porous materials as -B-O-, -C-N-, -C-C-, and -C-O- linkage-based COFs. Recently, the biomedical applications of COFs have become more and more attractive in biomedical applications, including drug delivery, bioimaging, biosensing, antimicrobial, and therapeutic applications, as these materials bear well-defined crystalline porous structures and well-customized functionalities. However, the clinical translation of these research findings is challenging due to the formidable hindrances for in vivo use, such as low biocompatibility, poor selectivity, and long bio-persistence. Some attempts have raised a promising solution towards these obstacles by tailored engineering the functionalities of COFs. To speed up the clinical translations of COFs, a short review of principles and strategies to tune the physicochemical properties of COFs is timely and necessary. In this review, we summarized the biomedical utilities of COFs and discussed the related key physicochemical properties. To improve the performances of COFs in biomedical uses, we propose approaches for the tailored functionalization of COFs, including large-scale manufacture, standardization in nanomedicines, enhancing targeting efficacy, maintaining predesigned functions upon transformations, and manipulation of multifunctional COFs. We expect that this minireview strengthens the fundamental understandings of property-bioactivity relationships of COFs and provides insights for the rational design of their high-order reticular structures.

关键词： Densities   Viscosities   Vit.C   Lithium chloride   DFT  

摘要： Densities (rho) and viscosities of vitamin L-ascorbic acid (LAA) in the presence of LiCl in aqueous media have been calculated over the temperature range 288.15-298.15 K. The values of densities increase with increases in concentrations of solute and co-solutes and decreases with temperature. The apparent molar volume (V(phi)0), partial molar volume (Delta V-tr(phi)?) and viscosity B-Coefficient (Delta B-tr) have been calculated from the density data and further transfer parameters [partial transfer volume of (ntrV0?) and transfer values of B-Coefficient (ntrB)] for vitamin LAA have been calculated. The values of partial molar expensibilities and second order derivative have been deduced for the prediction of structure making and breaking nature of vitamin LAA in aqueous environment of LiCl. Delta S-2(o)# and Delta H-2(o)# are positive for LAA in co-solutes studied which advocate that the bond breaking and decrease in order is accompanied with the formation of the transition state. Further, DFT studied between LAA with [Li(H2O)(n)]+ have been performed to confirm the interactions as obtained from the experimental *** of the LAA in presence and absence of tetrahedrally hydrated lithium and chloride ions has been performed to find the excitation energy as well lambda(max). It is observed that maximum stabilization is achieved when lithium ions are tetrahedrally hydrated. Further effect of water as a solvent is studied on the most stable system. Further, the effect of temperature on the stability of the LAA along with tetrahedrally lithium and chloride ions at 398, 318 and 328 K has been investigated.

关键词： biomaterials   crosslinking   stimuli‐   sensitive polymers  

摘要： Due to the unique biophysicochemical characteristics of synthesized superhydrophilic poly[N-[tris(hydroxymethyl)methyl] acrylamide] (PTHMMA) and poly(vinyl alcohol) (PVA), in this study, we investigated the preparation of physically and chemically crosslinked thermosensitive double network (DN) hydrogels with superior mechanical properties. The effect of the combination of PTHMMA with PVA was further explored experimentally and theoretically. Moreover, adjusting the lower critical solution temperature (LCST) of PTHMMA/PVA DN hydrogels in the phosphate buffer was achieved by chemical alteration and crosslinking of water-soluble polymers. Changing the composition and the extent of ether/acetal linkages altered the LCST based on hydrophilic/hydrophobic composition, which decreased the complexity of adjusting hydrogels' temperature sensitivity. PTHMMA-comprising hydrogels were found to have non-Fickian and super case Iota Iota transport characters. Moreover, the construction of shrunken PVA at high temperature was tailored by introducing PTHMMA into the network to permit a relaxed drug release of indomethacin (IND) at 37 degrees C and pH 7.4. Finally, the tensile strength, the equilibrium water content, thermo-sensitivity, and cell viability behaviors suggest that these materials can be tailored for potential applications as biomaterials.

关键词： Amendment   biochar   naphthalene   phenanthrene   soil quality  

摘要： Soil properties are significantly influenced by the addition of biochar. Biochar improves soil quality as it increases the soil alkalinity, surface negative charge, nutrient retention capacity, porosity, organic carbon content and cation exchange capacity (CEC). The present research based on pot study was carried out in October 2015 to April 2016 with Prosopis juliflora biochar. We investigated the effect of different concentrations of biochar (1%, 5% and 10%) and polyaromatic hydrocarbons (50?mg/kg naphthalene and 100?mg/kg phenanthrene) on various physico-chemical parameters of sandy soil. Biochar application significantly helps to reduce the soil bulk density by 8.40%, 13.95% and 17.61%, respectively, as compared to control. Similarly, percent soil space was effectively decreased with increased biochar application rate from 8.4% to 17%. Porosity and water holding capacity were significantly increased with biochar application rate (0% < 1% <5% <10%). The non-significant (p???0.05) results were observed in case of increase in pH and electrical conductivity values in biochar-amended and non-biochar amended soil samples. CEC and soil organic carbon values were significantly increased from 26.54 to 33.18% and 38.54 to 51.63%, respectively, in 10% biochar-amended soil as compared to biochar non-amended soil. However, biochar nourishes soil that could be safely applied in agriculture for improvement of soil health and crop yield.

关键词： fluid   fluid interfaces   particles   colloids   interface-dominated materials  

摘要： Particle-laden fluid/fluid interfaces are ubiquitous in academia and industry, which has fostered extensive research efforts trying to disentangle the physico-chemical bases underlying the trapping of particles to fluid/fluid interfaces as well as the properties of the obtained layers. The understanding of such aspects is essential for exploiting the ability of particles on the stabilization of fluid/fluid interface for the fabrication of novel interface-dominated devices, ranging from traditional Pickering emulsions to more advanced reconfigurable devices. This review tries to provide a general perspective of the physico-chemical aspects associated with the stabilization of interfaces by colloidal particles, mainly chemical isotropic spherical colloids. Furthermore, some aspects related to the exploitation of particle-laden fluid/fluid interfaces on the stabilization of emulsions and foams will be also highlighted. It is expected that this review can be used for researchers and technologist as an initial approach to the study of particle-laden fluid layers.

关键词： Biomass   Biochar   Olive kernel   Torrefaction   Slow pyrolysis   CO2 and H2O gasification  

摘要： The thermochemical conversion of biomass through its gasification has been widely explored during the last decades. The generated bio-syngas mixture can be directly used as fuel in thermal engines and fuel cells or as intermediate building block to produce synthetic liquid fuels and/or value added chemicals at large scales. In the present work, the effect of Greek olive kernel (OK) thermal treatment (torrefaction at 300 degrees C vs. slow pyrolysis at 500 and 800 degrees C) on the physicochemical characteristics and CO2 or H2O gasification performance of as-produced biochars is examined. Both the pristine OK sample and biochars (OK300, OK500, OK800) were fully characterized by employing a variety of physicochemical methods. The results clearly revealed the beneficial effect of thermal pretreatment on the gasification performance of as-prepared biochars. A close relationship between the physicochemical properties of fuel samples and gas production was disclosed. Carbon dioxide gasification leads mainly to CO with minor amounts of H-2 and CH4, whereas steam gasification results in a mixture containing CO2, CO, H-2 and CH4 with a H-2/CO ratio varied between 1.3 and 2.3. The optimum gasification performance was obtained for the slowly pyrolyzed samples (OK500 and OK800), due to their higher carbon and ash content as well as to their higher porosity and less ordered structure compared to pristine (OK) and torrefied (OK300) samples. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Palladium   Reaction products   Metals   Absorption   Macrocycles  

摘要： Recent work has been developed on two new classes of neutral porphyrazine complexes of formulas [(PdCl2)(4)Py(8)PzM]center dot xH(2)O (Py(8)Pz = octakis(2-pyridyl)porphyrazinato anion;M = Mg-II(H2O), Zn-II, Pd-II) and [{Pd(CBT)(2)}(4)Py(8)PzM]center dot xH(2)O (M = Mg-II(H2O), Zn-II;CBT = m-carborane-1-thiolate anion). Characterization of all the species has been conducted by IR and UV-visible spectral measurements in a systematic comparison with the corresponding already known mononuclear species [Py(8)PzM] (M = Mg-II(H2O), Zn-II) and the mono-Pd-II analogue isolated and presented here for the first time. Comparison includes also the two parent classes of pentanuclear tetrapyrazinoporphyrazines having the more extended pi-electron delocalized macrocyclic core Py(8)TPyzPz. The reported new classes of pentanuclear complexes behave as active photosensitizers in photodynamic therapy (PDT), and due to the high boron content of the CBT derivatives, perspectives for them are open of application in the field of bimodal PDT/BNCT (boron neutron capture therapy) anticancer treatments.