Search

The results of applying heterogeneous chemiluminescent analysis for determination of micro-components are generalized, and the possibility of using this method for determination of toxic anions in waters is demonstrated. Anions undergo conversion beforehand, which causes formation of new analytical forms, i.e., derivates being active in chemiluminescent reactions with luminol. If volatile products are generated as analytical forms, they undergo gas extraction from the matrix with detection using a chemiluminescent indicator in the carrier gas stream at the interface gas-liquid (aqueous solution of luminol). Thus, the techniques for determination of Cl, Br, I, ClO, BrO, IO, NO, NO, S, CrO, AsO, Cl and chloramines are developed. The detection limit (DL) is 0.5-5.0 μg/l, and the analysis time is 2-9 min. In another case, products of conversion are sorbed from the solution on a solid sorbent, and detection is carried out by a luminol solution on the solid surface. A series of heteropoly acids (phosphorus, arsenic, silicon, and germanium) and their ion associates with cation surfactants, along with other large anions, are determined in the form of sorbable ion associates. The DL is 0.02-0.7 μg/l, and the analysis time is 30 min. The advantages of application of heterogeneous chemiluminescent analysis over analysis in homogeneous media are indicated, and the prospects for development of the theoretical bases and field of application are demonstrated. [ABSTRACT FROM AUTHOR]

The presence of reactive hydrogen-silyl (SiH) bonds in oligomethylhydridesiloxanes provides their widespread use in the building, paper, textile, and rubber industries. Low-molecular fractions of methylhydridesiloxanes, both cyclic and linear, adversely affect the operational properties of oligomer-based materials. The main goal of the present study is detection and identification of these fractions in a 136-157M commercial product, as well as in the co-oligomers synthesized from it. The method of gas chromatography–mass spectrometry has been used in the study. First, it has been proved that an increase in the temperature of the column and evaporator from 60 to 300°C does not change the composition of the low-molecular fractions. Consequently, there is no depolymerization processes related to the formation of low-molecular compounds during the analysis. To perform a qualitative analysis, the components of low-molecular fraction have been separated on a capillary column and then identified using a mass detector with an ion trap. It is shown that electron ionization triggers fragmentation of molecules and the formation of positively charged ions. As for methylhydridesiloxanes, cations with a molecular weight of [M – 15]+ arising from the rupture of the carbon-silyl bond are formed first. When such a rupture occurs in cyclosiloxanes with a total number of units of more than four, further dissociation processes can occur with the detachment of the neutral fragment (methylsilane) and the formation of bicyclosiloxane cations. Since the set of positive ions is individual for each of the components and depends on , a component-wise description of the entire low-molecular fraction becomes possible with a high degree of reliability. It is shown that, for the commercial sample under consideration, it can be described by two homologous series: cyclic , where m ≥ 4, and linear siloxanes , where n ≥ 1. [ABSTRACT FROM AUTHOR]

To quantitatively describe the kind of interaction between ion and solvent, it is convenient to use the concept of negative or positive solvation. We have established earlier that diffusion displacement distance ( d ¯ ) of an ion correlates with its solvation type. The ion is solvated positively if the average d ¯ value exceeds the crystallographic (structural) radius of an ion r i ; otherwise, ion solvation is negative. In this paper, we have estimated the length, time and velocity of ion diffusion displacement (hop) for singly charged ions Li + , Na + , K + , Rb + , Cs + , Me 4 N + , Et 4 N + , Bu 4 N + , F - , Cl - , Br - , BPh 4 - over the temperature range from 273.15 K to 473.15 K and for ions Pr 4 N + , I - , NO 3 - , ClO 4 - at 298.15 K in ethylene glycol. The fact of the negative solvation of almost all ions studied (except Li + , Na + , F - ) in ethylene glycol has been established for the first time. It has been shown that Me 4 N + ion has turned out solvated solvophilically in EG as well as in water while ions Et 4 N + , Bu 4 N + , and BPh 4 - appeared to be solvated solvophobically. We have estimated the temperature of transition T tr (from negative to positive ion solvation) for K + and Rb + ions. It physically corresponds to the absence of solvation of the ion ( d ¯ = r i ). [ABSTRACT FROM AUTHOR]

The paper deals with the gas-phase formation of nanoparticles that is a fundamental process responsible for the condensed matter in the Universe, which also attracts attention due to its involvement in the particle synthesis for various nanotechnology applications. Previously reported results on MgO nano-oxides formed by Mg combustion showed a unique phenomenon coined "the condensation stagnation" that is the occurrence of critical clusters with suppressed growth. Here we focus on the effect of an external ionizer on this condensation growth stagnation. We show that the condensation stagnation occurring in the Mg particle flame subjected to a positive ion flux is similar to that in the unaffected flame. In contrast, applying negative charging significantly influences the state of stagnation of the system, i.e., no critical clusters are observed in the products sampled from the flame. The discovered critical behavior of the state of stagnation is explained in terms of the heat transfer between the condensed MgO nanoparticles and the surrounding gas, which efficiency depends on the sign of the nanoparticle charge. This dependence of the heat transfer efficiency on the nanoparticle charge is a new fundamental effect that should become the basis for accurate modeling in two-phase high-temperature systems. [ABSTRACT FROM AUTHOR]

This paper describes the construction of the Periodic Tables for cations of all elements with charges + 1, + 2, + 3 and anions with charge − 1. The Table for cations+1 differs significantly from other newly constructed Tables and from known Tables, as the d- and f-blocks are inserted into s-block and split it up for two parts. Importantly, a new type of 3d- and 4f-shell contractions has been discovered. The manifestations of secondary periodicity in case of anions is absent or opposite to the manifestations observed for atoms and cations. For kainosymmetric anions, the ionization energies are lowered, which contradicts the theoretical assumptions and experimental data supporting the classical concept of kainosymmetry. Simple formulas are proposed for quantitative description of the manifestations of internal periodicity and kainosymmetry. The regularities of change in these manifestations depending on the charge and the position of ions or atoms in the Periodic Table are established. In the 6th period, the bifurcation in the properties characteristic of the internal periodicity does not occur at usual position, i.e. in the middle of the row from the block of the Periodic Table (p3–p4), but takes place earlier, along with the transition of the electronic configurations p2–p3. In other words, the place of transition from "early" to "late" elements changes. [ABSTRACT FROM AUTHOR]

This paper explores the head-on collision between two-counter propagating positron acoustic solitons and double layers (DLs) in an unmagnetized collisionless plasma having mobile cold positrons fluid, immobile positive ions and ( r , q )-distributed hot positrons, and hot electrons. By employing the extended Poincaré–Lighthill–Kuo method, the coupled Korteweg–de Vries (KdV), modified KdV (mKdV) and Gardner equations are derived to archive this goal. The effect of dimensionless parameters on the propagation characteristics of interacting KdV solitons (KdVSs), mKdV solitons (mKdVSs), Gardner solitons (GSs) and DLs are examined in detail by considering the limiting cases of ( r , q )-distribution. It is noted that the interaction of GSs and DLs are reported for the first time. The outcomes might be comprehended and beneficial not only in space and astrophysical environments but also in laboratory studies. [ABSTRACT FROM AUTHOR]

The experimental data reported in this paper suggest that titanium(IV) oxyhydroxyphosphate-based ion-exchange materials are potentially attractive for extraction of heavy metal cations from solutions. We have studied the time-dependent ion exchange activity of titanium phosphates for Zn2+, Co2+, and Ni2+ cations in relation to the liquid : solid ratio, temperature, and equilibrium pH of the cation exchange process. The results demonstrate that the selectivity of an ion exchanger for metal cations is determined by the ionic radii of the metals. Conditions for effective use of titanium phosphate materials for extraction of Zn2+, Co2+, and Ni2+ cations from solutions (liquid : solid ratio, temperature, and pH) have been optimized experimentally. [ABSTRACT FROM AUTHOR]

This paper reports the effect of different cations (Na, Mg and Li) while keeping perchlorate as the common anion on ion-dynamics behavior within polymer gel electrolytes containing tetraethylene glycol dimethyl ether (TEGDME) solvent and poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) as the polymer host. FTIR investigations demonstrate significant changes in characteristic bands, while XRD observations indicate prominent structural variation in terms of merger/suppression of phases when NaClO4, Mg(ClO4)2 and LiClO4 salts are immobilized in the PVdF-HFP/TEGDME matrix. The highest room temperature ionic conductivity of 1.2 × 10−3 S cm−1 with high dielectric constant value has been obtained for the Li+ conducting electrolyte composition due to its superior electrochemistry and ion-conduction behavior as compared to its Na+ and Mg2+ counterparts. In the low-frequency region, modulus curves reveal polarizing effects with long-range mobility/migration of Na/Mg/Li ions, while in the high-frequency region, a peak onset relating the translational ion dynamics and conductivity relaxation is observed. The reported polymer gel electrolytes may be employed as electronic materials for developing next-generation flexible electrochemical devices. [ABSTRACT FROM AUTHOR]

The results reported in this paper suggest that titanium(IV) oxyhydroxyphosphates can be used for sorption extraction of valuable metal cations from solutions, followed by desorption and concentration of the metal cations and simultaneous regeneration of the titanium phosphate material for further use. Conditions for effective desorption processes (desorbing agent concentration and desorption time) have been studied and optimized. The sorption/desorption process effectiveness in the case of multistep use of the sorbent has been shown to decline as a result of steric hindrances associated with its dehydration. As the sorption properties of the sorbent degrade, it can be used for extraction of trace amounts of highly toxic metal cations and then buried. [ABSTRACT FROM AUTHOR]

This paper demonstrates the feasibility of using titanium(IV) oxyhydroxyphosphate-based materials for sorption extraction of heavy metal cations from solutions. We have determined Pb2+ and Cd2+ sorption characteristics of ion exchangers, examined the kinetics of Pb2+ and Cd2+ sorption on the titanium phosphate materials, and assessed the effect of ionic radius on the affinity of the sorption matrices for metal cations. Conditions for effective use of the ion exchange materials for extracting Pb2+ and Cd2+ cations from solutions (liquid : solid ratio and pH) have been optimized experimentally. [ABSTRACT FROM AUTHOR]

Ternary metal oxide compounds, such as Ti-Nb and Nb-W oxides, have renewed research interest in energy storage materials because these oxides contain multivalent metal ions that may be able to control the ion transport in solid lithium batteries. One of these oxides is Ti2Nb10O29, which is composed of metal–oxygen octahedra connected through corner-sharing and edge-sharing to form "block structures". In the early 1970s Von Dreele and Cheetham proposed a metal-atoms ordering in this oxide crystal using Rietveld refined neutron powder diffraction method. Most recent studies on these oxides, however, have not considered cation ordering in evaluating the battery electrode materials. In this paper, by utilizing the latest scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy imaging technology, the cation chemical ordering in those oxide crystals was directly revealed at atomic resolution. [ABSTRACT FROM AUTHOR]

Performance of busbar insulators is affected by the accumulation of pollutants on their surfaces. The combined action of both the chemical and natural dust pollutants accumulated on the surfaces of the insulators results in the likelihood of surface flashovers. In this paper, the pollution level in terms of equivalent salt deposit density (ESDD) and chemical analyses of a 12-kV generator busbar insulators are carried out to identify the impacts of pollutants presented on the insulators. It is found by actual measurements that the ESDD values of five types of busbar insulators are 0.569, 1.66, 1.61, 1.58, and 2.44mg/cm2, respectively, and all of these values are beyond the acceptable limits. New mathematical models are proposed in between ESDD and chemical anions/cations using a multivariable linear regression analysis. A positive correlation is found between ESDD and cations for the T1-type insulator, whereas for the T5-type insulator, it is found between ESDD and anions. [ABSTRACT FROM AUTHOR]

Flexible control of the composition and morphology of nanocrystals (NCs) over a wide range is an essential technology for the creation of functional nanomaterials. Cation exchange (CE) is a facile method by which to finely tune the compositions of ionic NCs, providing an opportunity to obtain complex nanostructures that are difficult to form using conventional chemical synthesis procedures. However, due to their robust anion frameworks, CE cannot typically be used to modify the original morphology of the host NCs. In this study, we report an anisotropic morphological transformation of Cu1.8S NCs during CE. Upon partial CE of Cu1.8S nanoplates (NPLs) with Mn2+, the hexagonal NPLs are transformed into crescent-shaped Cu1.8S–MnS NPLs. Upon further CE, these crescent-shaped NPLs evolve back into completely hexagonal MnS NPLs. Comprehensive characterization of the intermediates reveals that this waxing-and-waning shape-evolution process is due to dissolution, redeposition, and intraparticle migration of Cu+ and S2−. Furthermore, in addition to Mn2+, this CE-induced transformation process occurs with Zn2+, Cd2+ and Fe3+. This finding presents a strategy by which to create heterostructured NCs with various morphologies and compositions under mild conditions. The robust anion framework of ionic nanocrystals impedes shape change by cation exchange. Here, the authors report an anisotropic, regenerative transformation of Cu1.8S nanoplates during cation exchange. [ABSTRACT FROM AUTHOR]

A theoretical investigation of the phase-mixing phenomenon of Langmuir oscillations (LOs) in a multi-component dusty plasma is presented. The plasma under study is a four-component plasma consisting of electrons, positrons, singly ionised positive ions and positive (or negative) polarity dust grains. The massive dust grains are assumed to form a fixed charge neutralising background, while the electrons, positrons and ions are considered to take part in the wave dynamics. A simple perturbative analysis of the governing fluid-Maxwell's equations leads us to an approximate relation for phase-mixing time of LOs, improving some earlier existing results. It is revealed that even though the dust grains remain motionless in the background, they still have significant impact on the phase-mixing process of LOs in such plasmas. It is found that the nature of the charge on the dust grains and the equilibrium dust density profoundly affect the phase-mixing time. The results of this investigation is expected to have relevance in space-plasma environments. [ABSTRACT FROM AUTHOR]

In the present paper we employ a series of dicationized (K& C; C = H, Li, Na, or K) hexapeptide (GCK, x = 1, 2, ... or 5) complexes in gas phase (GP) and aqueous phase (AP) as models to mimic the key characteristics of the real biosystems. An interesting phenomenon is observed that the binding properties of K to GC species change in the two phases, i.e., those positive binding energies in the GP become negative ones in the AP. Then we probe the origin of property change of the binding energies in the two different phases and associate these changes with some biological phenomena. [ABSTRACT FROM AUTHOR]

Hexavalent iron species (Fe(VI)) have been known for over a century, and have long-time been investigated as the oxidant for water purification, as the catalysts in organic synthesis and more recently as cathodic charge storage materials. Conventional Fe(VI) syntheses include solution phase oxidation (by hyphchlorite) of Fe(III), and the synthesis of less soluble super-irons by dissolution of FeO4, and precipitation with alternate cations. This paper reviews a new electrochemical Fe(VI) synthesis route including both in situ and ex situ syntheses of Fe(VI) salts. The optimized electrolysis conditions for electrochemical Fe(VI) synthesis are summarized. Direct electrochemical synthesis of Fe(VI) compounds has several advantages of shorter synthesis time, simplicity, reduced costs (no chemical oxidant is required) and providing a possible pathway towards more electro-active and thermal stable Fe(VI) compounds. Fe(VI) analytical methodologies summarized in this paper are a range of electrochemical techniques. Fe(VI) compounds have been explored as energy storage cathode materials in both aqueous and non-aqueous phase in “super-iron” battery configurations. In this paper, electrochemical synthesis of reversible Fe(VI/III) thin film towards a rechargeable super-iron cathode is also summarized. [ABSTRACT FROM AUTHOR]2−, and precipitation with alternate cations. This paper reviews a new electrochemical Fe(VI) synthesis route including both in situ and ex situ syntheses of Fe(VI) salts. The optimized electrolysis conditions for electrochemical Fe(VI) synthesis are summarized. Direct electrochemical synthesis of Fe(VI) compounds has several advantages of shorter synthesis time, simplicity, reduced costs (no chemical oxidant is required) and providing a possible pathway towards more electro-active and thermal stable Fe(VI) compounds. Fe(VI) analytical methodologies summarized in this paper are a range of electrochemical techniques. Fe(VI) compounds have been explored as energy storage cathode materials in both aqueous and non-aqueous phase in “super-iron” battery configurations. In this paper, electrochemical synthesis of reversible Fe(VI/III) thin film towards a rechargeable super-iron cathode is also summarized. [ABSTRACT FROM AUTHOR]

This paper outlines the effect of (Mn + F) double doping on the structural, morphological, optoelectronic, magnetic and antibacterial properties of CdO thin films. Undoped CdO, Mn-doped CdO and (Mn + F) doubly doped CdO films exhibit face-centered cubic structure with a strong (1 1 1) preferential growth. Crystallite size value of the undoped film estimated using the Scherrer formula decreases with Mn doping and with double doping it increases. Cauliflower shaped nanostructures are evinced from the SEM images. Increased optical transparency is observed for the doubly doped films. The optical band gap value of the Mn-doped CdO film is found to be red shifted and for the (Mn + F) doubly doped films it is blue shifted which may be attributed to the Moss-Burstein effect. Ferromagnetic ordering is observed for the doped films. The doped films show increased antibacterial efficiency against K. pneumonia a gram −ve bacteria. The obtained results infer that the CdO films doubly doped with Mn (cationic) and F (anionic) ions exhibited better optical, electrical, magnetic and antibacterial properties. [ABSTRACT FROM AUTHOR]

Research for synthesis of size-controlled carriers is currently challenging one. In this research paper, a method for size-controlled synthesis of biodegradable nanocarriers is proposed and described. Salting out method is suitable for both hydrophilic and hydrophobic drugs for the encapsulation on carriers. This synthetic method is based on polylactic acid (PLA) and non-ionic carboxymethyl cellulose (CMC) composed by CaCl as salting out agent. This method permits size-controlled synthesis of particles between 50 and 400 nm simply by varying the concentration of salting out agents. We have prepared cisplatin (CDDP)-loaded PLA-CMC nanocarriers by salting out method, with varying salting out agent (CaCl) concentrations as 0.05, 0.2, 0.35 and 0.5 M. The nanocarriers were characterized for their size, surface charge and morphology by atomic force microscope, zeta potential analyser and transmission electron microscope, respectively. The encapsulation efficiency and in-vitro drug-releasing behaviour of the nanocarriers were investigated. The cytotoxicity effect of nanocarriers and drug-loaded nanocarriers was tested against MCF-7 breast cancer cell line. [ABSTRACT FROM AUTHOR]

In the Periodic Tables the transition from atoms to double-charged cations is accompanied by alterations in the composition of s and p blocks and reciprocal location of blocks, as well as by changes in the composition and length of periods. We have previously described the relationship between the atom properties and the total number of differentiating electrons. This paper demonstrates that, despite the above transition-related alterations, this relationship is also valid for the description of the properties of double-charged cations. This can be exemplified by the dependence of the ionization energy on the total number of p electrons in p block, d electrons in d block, and f electrons in f block. Furthermore, a single periodic equation is sufficient for the description of properties of all of double-charged cations from each block. [ABSTRACT FROM AUTHOR]

Highlights: In situ Raman spectroscopy study of the cation regulation for interfacial water on Au@Pd core–shell nanoparticle surface during hydrogen evolution reaction process. Direct spectral evidence reveals new strategies to optimize the structure of interfacial water by the adjusting of radius and valence of the cation in the electrolyte. The optimized structure of interfacial water will improve the charge transfer efficiency between the water and electrode increasing the performance of the hydrogen evolution reaction. Interfacial water molecules are the most important participants in the hydrogen evolution reaction (HER). Hence, understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism. Unfortunately, investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment. Here, the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry, in situ core–shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques. Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction. When comparing the different cation electrolyte systems at a given potential, the frequency of the interfacial water peak increases in the specified order: Li+ < Na+ < K+ < Ca2+ < Sr2+. The structure of interfacial water was optimized by adjusting the radius, valence, and concentration of cation to form the two-H down structure. This unique interfacial water structure will improve the charge transfer efficiency between the water and electrode further enhancing the HER performance. Therefore, local cation tuning strategies can be used to improve the HER performance by optimizing the interfacial water structure. [ABSTRACT FROM AUTHOR]

Counter to synthetic convention and expectation provided by the relevant standard reduction potentials, the chloroberyllate, [{SiNDipp}BeClLi]2 [{SiNDipp} = {CH2SiMe2N(Dipp)}2; Dipp = 2,6-i-Pr2C6H3)], reacts with the group 1 elements (M = Na, K, Rb, Cs) to provide the respective heavier alkali metal analogues, [{SiNDipp}BeClM]2, through selective reduction of the Li+ cation. Whereas only [{SiNDipp}BeClRb]2 is amenable to reduction by potassium to its nearest lighter congener, these species may also be sequentially interconverted by treatment of [{SiNDipp}BeClM]2 by the successively heavier group 1 metal. A theoretical analysis combining density functional theory (DFT) with elemental thermochemistry is used to rationalise these observations, where consideration of the relevant enthalpies of atomisation of each alkali metal in its bulk metallic form proved crucial in accounting for experimental observations. Here the authors demonstate that counter to expectation provided by the relevant standard reduction potentials, a chloroberyllate, [{SiNDipp}BeClLi]2, reacts with the group 1 elements (M = Na, K, Rb, Cs) to provide the respective heavier alkali metal analogues, [{SiNDipp}BeClM]2. [ABSTRACT FROM AUTHOR]

Due to their intrinsic high reactivity, isolation of tin(0) complexes remains challenging. Herein, we report the synthesis of a silylene-stabilized ditin(0) complex (2) by reduction of a silylene-supported dibromostannylene (1) with 1 equivalent of magnesium (I) dimer in toluene. The structure of 2 was established by single crystal X-ray diffraction analysis. Density Functional Theory calculations revealed that complex 2 bears a Sn=Sn double bond and one lone pair of electrons on each of the Sn(0) atoms. Remarkably, complex 2 is readily methylated to give a mixed-valent methylditin cation (4), which undergoes topomerization in solution though a reversible 1,2-Me migration along a Sn=Sn bond. Computational studies showed that the three-coordinate Sn atom in 4 is the dominant electrophilic center, and allows for facile reaction with KHBBus3 furnishing an unprecedented N-heterocyclic silylenes-stabilized distannavinylidene (5). The synthesis of 2, 4 and 5 demonstrates the exceptional ability of N-heterocyclic silylenes to stabilize low valent tin complexes. Due to their intrinsic high reactivity, isolation of tin(0) complexes remains challenging. Here, the authors report the synthesis of a silylene-stabilized ditin(0) complex by reduction of a silylene-supported dibromostannylene and its conversion to methylditin cation and distannavinylidene [ABSTRACT FROM AUTHOR]

153-Residue copper-zinc superoxide dismutase 1 (hSOD1) is the first gene whose mutation was linked to FALS. To date, > 180 ALS-causing mutations have been identified within hSOD1, yet the underlying mechanism still remains mysterious. Mature hSOD1 is exceptionally stable constrained by a disulfide bridge to adopt a Greek-key β-barrel fold that accommodates copper/zinc cofactors. Conversely, nascent hSOD1 is unfolded and susceptible to aggregation and amyloid formation, requiring Zn2+ to initiate folding to a coexistence of folded and unfolded states. Recent studies demonstrate mutations that disrupt Zn2+-binding correlate with their ability to form toxic aggregates. Therefore, to decode the role of cations in hSOD1 folding provides not only mechanistic insights, but may bear therapeutic implications for hSOD1-linked ALS. Here by NMR, we visualized the effect of 12 cations: 8 essential for humans (Na+, K+, Ca2+, Zn2+, Mg2+, Mn2+, Cu2+, Fe2+), 3 mimicking zinc (Ni2+, Cd2+, Co2+), and environmentally abundant Al3+. Surprisingly, most cations, including Zn2+-mimics, showed negligible binding or induction for folding of nascent hSOD1. Cu2+ exhibited extensive binding to the unfolded state but led to severe aggregation. Unexpectedly, for the first time Fe2+ was deciphered to have Zn2+-like folding-inducing capacity. Zn2+ was unable to induce folding of H80S/D83S-hSOD1, while Fe2+ could. In contrast, Zn2+ could trigger folding of G93A-hSOD1, but Fe2+ failed. Notably, pre-existing Fe2+ disrupted the Zn2+-induced folding of G93A-hSOD1. Comparing with the ATP-induced folded state, our findings delineate that hSOD1 maturation requires: (1) intrinsic folding capacity encoded by the sequence; (2) specific Zn2+-coordination; (3) disulfide formation and Cu-load catalyzed by hCCS. This study unveils a previously-unknown interplay of cations in governing the initial folding of hSOD1, emphasizing the pivotal role of Zn2+ in hSOD1-related ALS and implying new hSOD1-dependent mechanisms for Cu2+/Fe2+-induced cytotoxicity, likely relevant to aging and other diseases. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of the electronic thermoelectric power as a function of copper content for LiCuS ( x ≤ 0.25) electronic-ionic mixed conductors. Using a vacancy model for lattice defects, we calculate their electronic thermoelectric power as a function of x. By adjusting the hole effective mass, we reach satisfactory agreement with experimental data. [ABSTRACT FROM AUTHOR]

While many attempts have been made in the recent past to improve the power conversion efficiencies of dye-sensitized solar cells (DSSCs), only a few reports can be found on the study of these cells using binary iodides in the gel polymer electrolyte. This paper reports the effect of using a binary mixture of (large and small cation) alkaline salts, in particular CsI and LiI, on the efficiency enhancement in DSSCs with gel polymer electrolytes. The electrolyte with the binary mixture of CsI:LiI = 1:1 (by weight) shows the highest ionic conductivity 2.9 × 10 S cm at 25 °C. DC polarization measurements showed predominantly ionic behavior of the electrolyte. The density of charge carriers and mobility of mobile ions were calculated using a newly developed method. The temperature dependent behavior of the conductivity can be understood as due to an increase of both the density and mobility of charge carriers. The solar cell with only CsI as the iodide salt gave an energy conversion efficiency of ~3.9 % while it was ~3.6 % for the cell with only LiI. However, the electrolyte containing LiI:CsI with mass ratio 1:1 showed the highest solar cell performance with an energy conversion efficiency of ~4.8 % under the irradiation of one Sun highlighting the influence of the mixed cation on the performance of the cell. This is an efficiency enhancement of 23 %. [ABSTRACT FROM AUTHOR]

Background: The derivatives of 2-substituted 4H-3,1-benzoxazin-4-one belong to a significant category of heterocyclic compounds, which have shown a wide spectrum of medical and industrial applications. Results: A new and effective one-pot method for the synthesis of 2-substituted 4H-3,1-benzoxazin-4-one derivatives is described in this paper. By using the iminium cation from a mixture of cyanuric chloride and dimethylformamide as a cyclizing agent, a series of 2-substituted 4H-3,1-benzoxazin-4-one derivatives was synthesized in high yield under mild conditions and simple workup. Conclusions: The iminium cation from a mixture of cyanuric chloride and N,N-dimethylformamide is an effective cyclizing agent for the room temperature one-pot synthesis of 2-substituted 4H-3,1-benzoxazin-4-one derivatives in high yields through a cyclodehydration reaction. Furthermore, the method was performed under mild conditions characterized by simplified pathways and workup, minimized energy, and fewer reaction steps, compared with the previous methods. The proposed method, which is a simpler alternative than the published methods, is applicable for the synthesis of other 2-substituted 4H-3,1-benzoxazin-4-one derivatives. [ABSTRACT FROM AUTHOR]

The results of research on the effects of anions on the biosorption of microelement cations by the edible marine macroalga Enteromorpha prolifera in single- and multi-metal systems are discussed in this paper. It was shown that the maximum biosorption capacity ( q) in a single-metal system of Co(II) ions decreased in the following sequence: Cl (46.0 mg g) > SO (42.8 mg g) > NO (41.9 mg g). In multi-metal systems, in which the ratios of Cl, NO, and SO were 0:0:4, 1:1:2, 3:0:1, and 4:0:0, there were clear differences among the biosorption capacities. In all the examined systems (other than the 0:0:4 system), inhibition of the binding of microelement cations by the macroalga was observed. In all the systems, the highest value of q was obtained for Cu(II) cations; the value ranged from 31.9 mg g in 0:0:4 (SO only) to 18.2 mg g in 4:0:0 (Cl only). [ABSTRACT FROM AUTHOR]

A significantly large volume of effluent is generated during the manufacture of sugar and contains high amount of pollution load. The effluent from sugarcane industry is disposed off on land moves into the wider environment through a number of routes and the soil itself retains the various contaminants in the effluent to a greater or lesser extent depending on the physical nature of the soil. The analysis of contaminant transport through soil used to design of industrial wastewater treatments and disposal systems. This paper discussed the adsorption and diffusion of cations calcium, magnesium, sodium and anions chloride and sulphate by the sorption diffusion permeameter under different hydraulic retentions time of 3 min, 13 min, 27 min and 58 min with a constant diffusion flow rate of 3.6 L/h. In this study, less percentage error found between observed adsorption and diffusion coefficients from the experiments at different hydraulic retentions time and optimum adsorption and diffusion coefficients from the experiments at optimum hydraulic retentions time of 30 min for calcium, magnesium, sodium, choloride and sulphate. The results of regression analysis implied that the adsorption and diffusion coefficients obtained from the equation for cations and anions were good recognizing with the experimental results. [ABSTRACT FROM AUTHOR]

In this paper, electrical and structural properties of mono-, di-, tri- and tetrachlorothiophenes and their radical cations have been studied using the density functional theory and B3LYP method with 6-311++G** basis set. The effects of the number and position of the substituent of chlorine atoms on the properties of the thiophene ring for all chlorothiophenes and their radical cations have been studied. Vibrational frequencies, nuclear chemical shielding constants, spin-density distribution, size and direction of dipole moment vector, ionization potential, electric polarizabilities and NICS values of these compounds have been calculated as well. The analysis of these data showed that double bonds in 3-chlorothiophene are more delocalized and it is the best possible candidate monomer among all chlorothiophenes for the synthesis of corresponding conducting polymers with modified characteristics. [ABSTRACT FROM AUTHOR]

This paper examines the modification of zeolites with superstoichiometric amounts of metals using multistep cluster synthesis. Ion-exchange sites in zeolite MFI-50 (SiO/AlO molar ratio of 50) have been modified with hydrazonium cations. Subsequent redox reaction with chromate anions has yielded a chromium-containing zeolite. The sample prepared by three ion-exchange/redox cycles contains 10 wt % chromium (Cr-MFI-50). EPR results show that most of the chromium in Cr-MFI-50 is in the form of fine CrO particles. In addition, the material contains isolated Cr ions and, presumably, Cr stabilized at aluminum vacancies. [ABSTRACT FROM AUTHOR]

Salts of sulfonated polyphenylquinoxaline (SPPQ) containing alkaline earth metal ions-Mg, Ca, and Ba-were synthesized. The paper considers their solubilities, the properties of solutions, and thermal stability in comparison with analogous characteristics of SPPQ salts with alkali metals. The introduction of alkaline earth metal cations into SPPQ affords soluble polymeric salts having high thermal stability. Solutions of SPPQ salts in N-methylpyrrolidone (N-MP) containing Mg, Ca, and Ba ions do not exhibit polyelectrolyte properties, unlike solutions of SPPQ salts in which the counterions are Li, Na, and K. Solutions of SPPQ and its salts in N-MP can be converted to water-soluble form by dialysis. This opens up new prospects for using the polymeric salts. [ABSTRACT FROM AUTHOR]

Green leaf tissues convert solar energy into the energy of chemical bonds of sugar molecules during the process of photosynthesis. The efficiency of this conversion can be much higher than the efficiency of any of the currently known silicon-based solar panels. Importantly, vast amounts of CO2 are assimilated during this process. The efficiency of photosynthesis is critically dependent on the availability of a large number of nutrients, among which metal cations such as K, Ca, Mg, Cu, Zn, Fe, Mn, and Ni play a key role. This paper summarizes the basic requirements and major functions for each of these essential nutrients in plant photosynthesis, both at the whole-plant and molecular level. Also discussed is how these requirements may be affected by the global climate trends and the prospects of creating artificial photosynthetic “bioreactors” for efficient energy conversion and CO2 assimilation. [ABSTRACT FROM AUTHOR]

It is well established that dry etching of HgCdTe by Ar ion-beam milling (IBM) converts vacancy-doped p-type HgCdTe to n-type. Less well established is the understanding of the observed rate of conversion. This paper shows that the observed variations of the depth of conversion with milling time can be accounted for in terms of two rate processes operating in tandem. The first process is the diffusion of Hg interstitials from the surface to the conversion boundary followed by the second, or conversion, process that is the capture of the Hg interstitials by cation vacancies. Assuming steady-state conditions exist a quadratic equation is derived for the conversion depth and its milling-time dependence for two cases: when the initial p-type layer is electrically intrinsic at the milling temperature and when it is extrinsic. Good agreement is found with the available experimental Ar-ion-milling data. Good agreement is also found for type conversion due to etching with a radio-frequency Ar plasma. The effect of capture of Hg interstitials by traps, in addition to capture by cation vacancies, is also considered. [ABSTRACT FROM AUTHOR]

This paper reports a novel configuration of stacked microbial fuel cells (MFCs) bridged internally through an extra cation exchange membrane (CEM). The MFC stack (MFCstack), assembled from two single MFCs (MFCsingle), resulted in double voltage output and half optimal external resistance. COD removal rate was increased from 32.4% to 54.5%. The performance improvement could be attributed to the smaller internal resistance and enhanced cations transfer. A result from a half cell study further confirmed the important role of the extra CEM. This study also demonstrated MFCs where the anode and cathode were sandwiched between two CEMs possessed significantly high power outputs [ABSTRACT FROM AUTHOR]

Many geochemical models of major igneous differentiation events on the Earth, the Moon, and Mars invoke the presence of garnet or its high-pressure majoritic equivalent as a residual phase, based on its ability to fractionate critical trace element pairs (Lu/Hf, U/Th, heavy REE/light REE). As a result, quantitative descriptions of mid-ocean ridge and hot spot magmatism, and lunar, martian, and terrestrial magma oceans require knowledge of garnet-melt partition coefficients over a wide range of conditions. In this contribution, we present new crystal-chemical and thermodynamic constraints on the partitioning of rare earth elements (REE), Y and Sc between garnet and anhydrous silicate melt as a function of pressure ( P), temperature ( T), and composition ( X). Our approach is based on the interpretation of experimentally determined values of partition coefficients D using lattice-strain theory. In this and a companion paper (Draper and van Westrenen this issue) we derive new predictive equations for the ideal ionic radius of the dodecahedral garnet X-site, r 0(3+), its apparent Young’s modulus E X(3+), and the strain-free partition coefficient D 0(3+) for a fictive REE element J of ionic radius r 0(3+). The new calibrations remedy several shortcomings of earlier lattice-strain based attempts to model garnet-melt partitioning. A hitherto irresolvable temperature effect on r 0(3+) is identified, as is a pronounced decrease in E X(3+) as Al on the garnet Y site is progressively replaced by quadruvalent cations (Si, Ti) as pressure and garnet majorite content increase. D 0(3+) can be linked to the free energy of fusion of a hypothetical rare-earth garnet component JFe2Al3Si2O12 through simple activity-composition relations. By combining the three lattice-strain parameter models, garnet-anhydrous melt and majorite-anhydrous melt D values for the REE, Y and Sc can be predicted from P, T, garnet major element composition, and melt iron content at pressures from 2.5–25 GPa and temperatures up to 2,573 K, covering virtually the entire P– T range over which igneous garnets are stable in solar system compositions. Standard deviations of the difference between predicted and observed D REE,Y,Sc range from 25% for Er to 70% for Ce, and are not correlated with trace element mass. The maximum error in D prediction ( n > 300) is 218% for one measurement of D Dy. This is remarkably low considering the total spread in D values of over four orders of magnitude. [ABSTRACT FROM AUTHOR]

As a complement to our efforts to update and revise the thermodynamic basis for predicting garnet-melt trace element partitioning using lattice-strain theory (van Westrenen and Draper in Contrib Mineral Petrol, this issue), we have performed detailed statistical evaluations of possible correlations between intensive and extensive variables and experimentally determined garnet-melt partitioning values for trivalent cations (rare earth elements, Y, and Sc) entering the dodecahedral garnet X-site. We applied these evaluations to a database containing over 300 partition coefficient determinations, compiled both from literature values and from our own work designed in part to expand that database. Available data include partitioning measurements in ultramafic to basaltic to intermediate bulk compositions, and recent studies in Fe-rich systems relevant to extraterrestrial petrogenesis, at pressures sufficiently high such that a significant component of majorite, the high-pressure form of garnet, is present. Through the application of lattice-strain theory, we obtained best-fit values for the ideal ionic radius of the dodecahedral garnet X-site, r 0(3+), its apparent Young’s modulus E(3+), and the strain-free partition coefficient D 0(3+) for a fictive REE element J of ionic radius r 0(3+). Resulting values of E, D 0, and r 0 were used in multiple linear regressions involving sixteen variables that reflect the possible influence of garnet composition and stoichiometry, melt composition and structure, major-element partitioning, pressure, and temperature. We find no statistically significant correlations between fitted r 0 and E values and any combination of variables. However, a highly robust correlation between fitted D 0 and garnet-melt Fe–Mg exchange and D Mg is identified. The identification of more explicit melt-compositional influence is a first for this type of predictive modeling. We combine this statistically-derived expression for predicting D 0 with the new expressions for predicting E and r 0 outlined in the first of our pair of companion papers into an updated set of formulae that use easy-to-measure quantities (e.g. garnet composition, pressure, temperature) to predict variations in E, r 0, and D 0. These values are used in turn to calculate D values for those garnets. The updated model substantially improves upon a previous model (van Westrenen et al. in Contrib Mineral Petrol 142:219–234, ), and accounts well for trivalent cation partitioning in nominally anhydrous systems up to at least 15 GPa, including for eclogitic bulk compositions and for Fe-rich systems appropriate to magmagenesis on the Moon and Mars. The new model is slightly less successful in predicting partitioning with strongly majoritic garnets, although the mismatch is much less than with the original 2001 model. Although it also improves upon the 2001 model in predicting partitioning in hydrous systems, the mismatch between model and observation is still unacceptably large. The same statistical tools were applied in an attempt to predict tetravalent partitioning as well, because lattice-strain based techniques are not applicable to such partitioning. However, no statistically significant predictive relationships emerged from that effort. Our analyses show that future efforts should focus on filling the gap in partitioning data between ∼10 and 25 GPa to evaluate more closely the gradual transition of garnet to majorite, and on systematically expanding the hydrous partitioning database to allow extension of our model to water-bearing systems. [ABSTRACT FROM AUTHOR]

This paper introduces the development of an original PVC membrane electrode, based on 4-chloro-1,2-bis(2-pyridinecarboxamido)benzene (CBPB) as a suitable carrier for the Ho3+ ion. The electrode presents a Nernstian slope of 19.7 ± 0.3 mV per decade for the Ho3+ ions across a broad working concentration range from 1.0 × 10−6 to 1.0 × 10−2 M. The lower detection limit was 8.5 × 10−7 M in the pH range 2.7–9.8, while the response time was rapid (<15 s). Therefore, this potentiometric sensor displayed good selectivity for a number of cations such as alkali, alkaline earth, transition and heavy metal ions. The practical applicability of the electrode was demonstrated by its use as an indicator electrode in the potentiometric titration of Ho3+ ions with EDTA and in the determination of F- in mouth wash samples. [ABSTRACT FROM AUTHOR]

Based on a combination of experimental and theoretical studies of the absorption spectra (UV and IR) of diazonium salts (dimethylaminophenyldiazonium borofluoride) in different types of solutions, we have shown that the broad absorption band has vibrational structure, where the position of the components is regularly shifted depending on the solvent polarity, while the optical density and the position of the band depend on the nature of the solvation shell in the mixed solvent water:ethanol. A thermodynamic description of experimental data on the effect of the solvation shell on the optical density of the diazonium salt allowed us to show that the quantitative composition of the solvation shell differs from the composition of the mixed solvent: when the ethanol content in the solvent is less than 20 vol.%, there are practically no ethanol molecules in the solvation shell; when the ethanol content is greater than 80 vol.%, water molecules are missing from the solvation shell. [ABSTRACT FROM AUTHOR]

In order to investigate the dissolution process of metakaline in alkaline solutions, two 6-memebered rings models consisting of AlO4 tetrahedron and SiO4 tetrahedron, respectively are firstly proposed to represent the structure of metakaoline in this paper. Analysis of the dissolution mechanism of the two 6-memebered rings models in strongly solution reveals that the dissolution process of metakaoline is composed of ring breakage for releasing HOTO anion, formation of HO–T(OM)3 by ion-pairing reaction between HOTO anion and M+ cation, and further interaction between the remaining broken ring cluster and MOH solutions. A computational chemistry method: Semi-empirical AM1 calculation is then conducted on the two models to obtain the details of three steps involved in dissolution process. The calculated results showed that 6-member ring model consisting of AlO4 tetrahedron is more reactive than 6-member ring model consisting of SiO4 tetrahedron. Compared with local environment, strongly alkaline accelerated the dissolution of 6-member ring model consisting of SiO4 tetrahedron. Na+ has stronger ion-pairing interaction than K+. The further reaction between the remaining broken ring cluster and strongly alkaline solution depended on the types of the remaining broken ring cluster and alkaline solution. The above results enhanced our understanding of dissolution mechanisms of metakaoline in highly alkaline solutions, which is especially important to geopolymerization reaction. [ABSTRACT FROM AUTHOR]

This paper describes the development and validation of a sequential injection (SI) anodic stripping voltammetry (ASV) method using the hanging mercury drop electrode for accumulation of the heavy metal cations Cu(II), Pb(II) and Cd(II). The method was applied to wastewater samples after proper acid digestion in open vessels to eliminate matrix effects. For a deposition time of 90 s at the flow rate of 10 μl s−1, the detection limits of the method were 0.06, 0.09 and 0.16 μmol L−1 for Cd, Pb and Cu, respectively. Under these conditions the linear dynamic range was between 0.20 and 9.0 μmol L−1 and the sampling frequency was 30 analyses per hour. The relative standard deviation of the method was 3%( n=7) at the concentration level of 2.0 μmol L−1. The accuracy of the method was evaluated by spiking the samples with known amounts of the metal cations, and by comparison with an independent analytical technique, the inductively coupled plasma atomic emission spectroscopy (ICP-AES). Average recoveries were around of 84%, and the results showed no evidence of systematic errors in comparison to the ICP-AES. [ABSTRACT FROM AUTHOR]

Current research indicates that replacing organic solvents with room-temperature ionic liquids may lead to remarkable improvements in well-known processes. Ionic liquids have already been utilized as alternative solvents in organic synthesis and catalysis, and also in electrochemistry and in separation sciences. Their wide applicability will soon result in their production on an industrial scale. Therefore, analytical methods applicable to various matrices for product control and environmental monitoring will be very much in demand. In this study, the usefulness of π...π interactions between alkylimidazolium and pyridinium cations and the aromatic π...π active moiety of the stationary phase was investigated for the selective separation and analysis of some ionic liquids. With phenyl-bonded phases, very good separations of the cations were achieved. Special attention was paid to the short-chain hydrophilic entities, known to be poorly separated on conventional reversed-phase columns. Further, the nature of the interactions occurring in the system under study was investigated by varying the content of methanol/acetonitrile used as organic modifiers in the mobile phases. The analytical method developed here is simple and reproducible, and its quantitative analytical performance was excellent. The paper also discusses the applicability of the method for monitoring degraded cations of 1-butyl-3-methylimidazolium salts obtained in the Fenton process. [ABSTRACT FROM AUTHOR]

Owing to their favorable properties, ionic liquids have recently gained recognition as possibly environmentally benign solvents. Now among the most promising industrial chemicals, they have already been labeled “green”, but this appellation seems due entirely to their very low vapor pressure. This growing interest in the various applications of ionic liquids will soon result in their presence in the environment. Therefore, reliable analytical tools for the environmental analysis of ionic liquids need to be developed urgently. This paper presents a newly developed analytical procedure for the enrichment of 1-alkyl- and 1-aryl-3-methylimidazolium ionic liquids from water samples. The method is based on cation exchange solid-phase extraction followed by selective elution. Pre-concentrated samples are subjected to high-performance liquid chromatography (HPLC) with an advanced methodology for qualitative and quantitative analysis. The overall procedure was verified by using standard spiked samples of tap water, seawater, and freshwater. [ABSTRACT FROM AUTHOR]

The paper examines the dynamical behavior of a radical cation (G+*) generated in a double stranded DNA for different oligonucleotide sequences. The resonance hole tunneling through an oligonucleotide sequence is studied by the method of numerical integration of self-consistent quantum-mechanical equations. The hole motion is considered quantum mechanically and nucleotide base oscillations are treated classically. The results obtained demonstrate a strong dependence of charge transfer on the type of nucleotide sequence. The rates of the hole transfer are calculated for different nucleotide sequences and compared with experimental data on the transfer from (G+*) to a GGG unit. [ABSTRACT FROM AUTHOR]

This paper reports the assessment of total arsenic and six arsenic species (As(III), As(V), MMA, DMA, AsBet, AsCol) as contaminants of mussel samples collected around the island of Sardinia and in the Gulf of Venice. The samples were analysed using cation- and anion-exchange HPLC-HG-AFS for speciation and ICP-AES for the total As determination. To ensure the robustness of the routine analytical method, the technique was validated using a candidate reference material, BCR-710, and good agreement was obtained. It was recognised that higher total arsenic concentration in mussels does not necessarily result in higher toxicity of mussel samples. [ABSTRACT FROM AUTHOR]

Mammalian cells express several types of lectins involved in intracellular trafficking, including endocytosis, interorganelle routing and putatively nuclear import. In order to enhance the gene transfer efficiency, glycosylated cationic polymers have been used as nonviral vectors. We developed a simple method to convert reducing saccharides into glycosynthons. Glycosynthons are used to synthesize cationic glycopolymers, called Glycofectins. Glycofectins interact with a plasmid to give a glycoplex, a compacted form of a polymer/DNA complex. The high glycoplex efficiency depends on the sugar involved in the uptake and in the intracellular trafficking of glycoplexes. The present paper deals with glycoplexes, with gene transfer into cystic fibrosis airway epithelial and gland serous cells, and with some of the problems that have to be solved before clinical trials. [ABSTRACT FROM AUTHOR]

Membranes with high ion permeability and selectivity are of considerable interest for sustainable water treatment, resource extraction and energy storage. Herein, inspired by K+ channel of streptomyces A (KcsA K+), we have constructed cation sieving membranes using MXene nanosheets and Ethylenediaminetetraacetic acid (EDTA) molecules as building blocks. Numerous negatively charged oxygen atoms of EDTA molecules and 6.0 Å two-dimensional (2D) sub-nanochannel of MXene nanosheets enable biomimetic channel size, chemical groups and tunable charge density for the resulting membranes. The membranes show the capability to recognize monovalent/divalent cations, achieving excellent K+/Mg2+ selectivity of 121.2 using mixed salt solution as the feed, which outperforms other reported membranes under similar testing conditions and transcends the current upper limit. Characterization and simulations indicate that the cation recognition effect of EDTA and partial dehydration effects play critical roles in cations selective sieving and increasing the local charge density within the sub-nanochannel significantly improves cation selectivity. Our findings provide a theoretical basis for ions transport in sub-nanochannels and an alternative strategy for design ions separation membranes. Membranes with fast and selective separation of ions are universally desired in many applications. Here, authors inspired by biological potassium ion channels have constructed an MXene based biomimetic ion channel membrane to achieve efficient separation of ions. [ABSTRACT FROM AUTHOR]

Divalent cation block is observed in various tetrameric ion channels. For blocking, a divalent cation is thought to bind in the ion pathway of the channel, but such block has not yet been directly observed. So, the behaviour of these blocking divalent cations remains still uncertain. Here, we elucidated the mechanism of the divalent cation block by reproducing the blocking effect into NavAb, a well-studied tetrameric sodium channel. Our crystal structures of NavAb mutants show that the mutations increasing the hydrophilicity of the inner vestibule of the pore domain enable a divalent cation to stack on the ion pathway. Furthermore, non-equilibrium molecular dynamics simulation showed that the stacking calcium ion repel sodium ion at the bottom of the selectivity filter. These results suggest the primary process of the divalent cation block mechanism in tetrameric cation channels. Divalent cation block is observed in various tetrameric ion channels. Here, authors use X-ray crystallography, electrophysiology and molecular dynamics simulations to reveal the mechanism of the divalent cation block on a prokaryotic sodium channel. [ABSTRACT FROM AUTHOR]

Fluorides have been identified as a key ingredient in interphases supporting aggressive battery chemistries. While the precursor for these fluorides must be pre-stored in electrolyte components and only delivered at extreme potentials, the chemical source of fluorine so far has been confined to either negatively-charge anions or fluorinated molecules, whose presence in the inner-Helmholtz layer of electrodes, and consequently their contribution to the interphasial chemistry, is restricted. To pre-store fluorine source on positive-charged species, here we show a cation that carries fluorine in its structure is synthesized and its contribution to interphasial chemistry is explored for the very first time. An electrolyte carrying fluorine in both cation and anion brings unprecedented interphasial chemistries that translate into superior battery performance of a lithium-metal battery, including high Coulombic efficiency of up to 99.98%, and Li0-dendrite prevention for 900 hours. The significance of this fluorinated cation undoubtedly extends to other advanced battery systems beyond lithium, all of which universally require kinetic protection of highly fluorinated interphases. Fluorides have been identified as a key ingredient in interphases supporting aggressive battery chemistries. Here, the authors show a positive charged organic cation carrying fluorine populates at the inner Helmholtz layer of the electrode and contributes to the interphasial chemistry. [ABSTRACT FROM AUTHOR]

The change in the resistive characteristics of lead silicate glasses (LSGs) after treatment in alkaline and acid solutions is studied. It is established that the chemical treatment of glasses and, accordingly, blanks of microchannel plates (MCPs) affects the high-temperature ionic conductivity at a constant activation energy of electrical conductivity. It is shown that the treatment of glasses in NaOH and HF solutions can significantly change the electrical resistance. [ABSTRACT FROM AUTHOR]