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Abstract: This study examines and quantifies the effect of cationic polyelectrolyte adsorption on paper on the aggregation and retention of gold nanoparticles (AuNPs) to optimize their Surface Enhanced Raman Scattering (SERS) enhancement factor and sensitivity. Aggregation of metallic nanoparticles is known as a key factor for intense SERS enhancement. Paper substrates were treated with aqueous solutions of cationic polyacrylamide (CPAM) varying in concentration, charge density, and molecular weight to control the AuNPs’ aggregate size distribution and surface coverage on paper. The Raman Enhancement Factor of AuNPs-CPAM paper was almost an order of magnitude greater than for the untreated AuNPs paper. The high loading and uniform distribution of AuNPs aggregates on CPAM pre-treated paper contributed toward the excellent SERS reproducibility, sensitivity, and high enhancement factor. This configuration of AuNP on paper was favoured by treating the substrate with CPAM solutions of higher concentrations, higher charge density, and greater molecular weight. [Copyright &y& Elsevier]

Organophilic and cationic montmorillonite is desirable for pitch control in the pulp and paper industry. In this paper, polyaminoamide–epichlorohydrin (PAE)-modified montmorillonite was prepared via either solution intercalation or melt intercalation of polyaminoamide into montmorillonite, followed by the reaction with epichlorohydrin. The modified montmorillonite samples were characterized by FTIR spectroscopy, X-ray diffraction, and thermal gravimetric analysis. The amount of PAE intercalated and the surface charge densities of cationic-modified montmorillonite were determined. It was found that melt intercalation appeared to be more effective in the inclusion of PAE than solution intercalation. However, both solution- and melt-intercalated samples with various surface charge densities exhibited strong affinity toward dispersed colloidal rosin acid. [Copyright &y& Elsevier]

This paper explores the thermodynamic behavior of aqueous solutions of four ionic liquids (ILs), namely 1-butyl-1-methylpyrrolidinium dicyanamide [BMPYR][DCA], 1-butyl-3-methylimidazolium dicyanamide [BMIM][DCA], 1-butyl-1-methylpyrrolidinium 1,1,2,2-tetrafluoroethanesulfonate [BMPYR][TFES], and 1-butyl-3-methylimidazolium 1,1,2,2-tetrafluoroethanesulfonate [BMIM][TFES]. The ionic liquids with [TFES] – anion (tetraflates) have been scarcely researched so far and therefore were characterized here with 1 H NMR spectroscopy and DSC calorimetry. In all four systems studied, water activity was systematically measured, the determinations being carried out in the whole composition range and at seven temperatures in the range from 288.15 K to 318.15 K. In addition, the mixing enthalpies in the IL dilute region for (water + DCA IL) systems and the solid-liquid equilibria for (water + TFES IL) systems were experimentally determined. The dependences of activity coefficients on temperature and composition were correlated ( i ) separately with appropriate flexible equations and ( ii ) simultaneously with an extended NRTL model. Both correlation approaches provide adequate description of mixture energetics and, as documented by comparisons with other relevant data, allow extrapolations of activity coefficients to both higher and lower temperatures as well as good predictions of excess enthalpy. Furthermore, the volumetric and viscosity behavior of highly dilute solutions of the ILs was explored. The concentration dependences of the apparent volume and viscosity were fitted well by the respective classical Redlich-Meyer and Jones-Dole equations. The values of partial molar volumes at infinite dilution were found to perfectly obey the ion additivity and correlate well with the intrinsic volume of IL molecule. Thermodynamic behavior of studied systems was compared to each other and discussed with respect to molecular interactions and nanostructure as well as to how involved ions affect it. [ABSTRACT FROM AUTHOR]

ABX 3 -type organic lead halide perovskites have gained increasing attention as light harvester for solar cells due to their high power conversion efficiency (PCE). Recently, it has become a trend to avoid the use of expensive hole-transport materials (HTMs) and precious metals, such as Au, to be competitive in future commercial development. In this study, we fabricated mixed-cation perovskite-based solar cells through one-step spin-coating using methylammonium (CH 3 NH 3 + ) and formamidinium (HN = CHNH 3 + ) cations to extend the optical absorption range into the red region and enhance the utilization of solar light. The synthesized hole-conductor-free cells with carbon electrode and mixed cations exhibited increased short-circuit current, outperforming the cells prepared with pure methylammonium, and PCE of 10.55%. This paper proposes an efficient approach for fabricating high-performance and low-cost perovskite solar cells. [ABSTRACT FROM AUTHOR]

Hydroxyapatite samples doped with different metal ions (HAP-M, M ​= ​Cu, Sr, Al, Ce, and Ti) were successfully prepared by a simple co-precipitation method for effective U(VI) uptake. The applications of HAP-M in capturing U(VI) were investigated. Besides, numerous characterizations were taken to study the chemical and physical properties of HAP-M. The critical factors affecting U(VI) adsorption were examined, such as pH, contact time, initial concentration of U(VI) and solution temperature. The present study revealed that the adsorption effect of HAP for U(VI) can be affected by doping metal cations with different ionic radii, and HAP doping with Ti4+ ions increased its adsorption selectivity to U(VI). With the increase of the molar ratio of doped Ti4+ ions (5%–20%), the adsorption selection of U(VI) on HAP-Ti is also gradually increasing. HAP-Ti is a potentially efficient adsorbent in removing U(VI) from radioactive solutions. Hydroxyapatite samples doped with different metal ions (HAP-M, M ​= ​Cu, Sr, Al, Ce, and Ti) were successfully prepared by a simple co-precipitation method for effective U(VI) uptake. The applications of HAP-M in capturing U(VI) were investigated. Besides, numerous characterizations were taken to study the chemical and physical properties of HAP-M. [Display omitted] • In this paper, we systematically investigated the effect of direct doping of cations with different ionic radii into HAP on its structure and physicochemical properties, and explored their effects on U(VI) adsorption. • The as-synthesized novel metal cation-doped hydroxyapatite (HAP-Ti) exhibited better adsorption selectivity for U(VI) than other prepared hydroxyapatites. [ABSTRACT FROM AUTHOR]

The influence of the types of interlayer cations on organic intercalation of montmorillonite (Mt) was studied in this paper. The distribution of Na + , K + , Mg 2+ , Ca 2+ and Fe 3+ in montmorillonite interlayer, their interaction with structure layers and the effect of interlayer cations on the basal spacing of Mt, the amount of binding water for different interlayer cations and the binding force between them were investigated systematically. 1-Hexadecy1-3-methylimidazolium chloride monohydrate (C 16 mimCl) was intercalated into montmorillonites with different interlayer cations. The influence of interlayer cations on organic intercalation was investigated. Molecular dynamics (MD) modeling was used to speculate the interlayer microstructures of the organically intercalated Mt with different interlayer cations. These simulations help to predict the microstructure of organo-Mt and guide their relevant engineering applications. [ABSTRACT FROM AUTHOR]

Abstract: This paper summarizes the conclusions of experiments conducted on the adsorption of Cd2+, Co2+, Cu2+, Mn2+, Ni2+, Pb2+ and Zn2+ onto zeolite. The focus of the experiments was to establish the influence of the initial pH of the contact solution as well as the selectivity of zeolite on the efficiency of the adsorption process. To this end, experimental adsorption isotherms were established for the pH values ranging from 1 to 4 by using the Na-form of clinoptilolite (particle size range 0.5–1 mm) as an adsorbent. Langmuir, Freundlich and Dubinin-Raduschkevich isotherm models were used to validate the experimental data and the Gibbs free energy was calculated based on the distribution coefficient. From the Langmuir model, correlations between the maximum adsorption capacity and selected physical–chemical parameters of the cations studied were established. The results of the experiments suggest that the selectivity of zeolite is strongly influenced by the pH of the contact solution, dehydration energy of cations, diffusion coefficient and the pH at which the precipitation of hydroxides occurs. [Copyright &y& Elsevier]

Abstract: The electronic and lattice dynamic properties of I 2–II–IV–VI 4 quaternary diamond-like semiconductors have a tight connection with their application in the area of solar cell absorption, thermoelectric conversion and so on. Structural configuration of these compounds is focused in present study, although previous researches always pay close attention to compositional modulation. In this paper, Ag2CdGeS4 polytypes (two types of Pna21, one type of Pmn21) have chosen as the representation to establish the relationship between cation ordering and physiochemical properties based on first-principle theory. The results show that cation arrangement practically affects their electronic and lattice dynamic properties such as bonding strength, band structure as well as their infrared spectrum. Due to different cation arrangement, two types (named model S and model P) of the same space group Pna21 demonstrate different properties. For both model P and Pmn21 of different space group, their related properties are alike because of similar cation arrangement. With the resulting cationic Born effective charges, the origin of the difference in electronic properties for three types of Ag2CdGeS4 can be reasonably explained from the viewpoint of vibrational polarization. [Copyright &y& Elsevier]

Abstract: In this paper, three new extended solid frameworks based on polyoxoanion [MnV13O38]7−: K0.5Na2.5Co2[MnV13O38]·22H2O (1), K1.5Na1.5Mn2[MnV13O38] 22H2O (2) and K0.5Na2.5Ni2[MnV13O38] 22H2O (3) have been synthesized and characterized by elemental analysis, IR spectrum, UV–Vis spectrum, thermal gravimetric analysis, magnetism, electrochemical analyses and single crystal X-ray diffraction. The structure analyses reveal that the polyoxoanions in compounds 1–3 are isostructural, which can be described as two transition metal-supported {M2(H2O)10(MnV13O38)} (M=Co2+, Mn2+ and Ni2+) units connected by a K+. And then the polyoxoanions are stacked by the electrostatic interactions with other K+ and Na+ cation to form a 2D layer. The variable-temperature magnetic susceptibility of compound 1 has been studied as the example, which shows an antiferromagnetic interaction. [Copyright &y& Elsevier]

Abstract: We have demonstrated that protein kinase Cδ (PKCδ) could be involved in macrophage apoptosis induced by cationic liposomes composed of stearylamine (SA-liposomes), but the detailed mechanism of how SA-liposomes activate PKCδ has remained unclear. In this paper, we clarified whether lipid rafts are involved in the PKCδ activation induced by SA-liposomes. Co-localization of SA-liposomes and Cholera toxin B subunit (CBT), which specifically binds to ganglioside GM1 on lipid rafts, was found by microscopic observation. The incorporation of SA-liposomes into lipid rafts was clearly inhibited by the pretreatment of cells with an agent, 2,6-di-O-methyl-α-cyclodextrin (DM-α-CD) which disrupts lipid rafts. Activation of PKCδ and externalization of phosphatidylserine induced by SA-liposomes were also suppressed by DM-α-CD, which extracts sphingolipids and proteins from lipid rafts. Reactive oxygen species (ROS) generation, which could be involved in the macrophage apoptosis, was also inhibited by DM-α-CD. Furthermore, apoptosis induced by SA-liposomes was clearly inhibited when the cells were pre-treated with DM-α-CD, but not nystatin, a cholesterol-sequestering agent that disrupt lipid rafts. These findings suggest that sphingolipids in lipid rafts are involved in the activation of PKCδ which leads to apoptosis induced by cationic liposomes, SA-liposomes. [Copyright &y& Elsevier]

Abstract: In this paper, the ionic liquids 1,2-diethylpyridinium ethylsulfate, EEpyESO4; 1-methylpyridinium methylsulfate, MpyMSO4; 1,3-dimethylpyridinium methylsulfate, MMpyMSO4; and 2-ethyl-1-methylpyridinium methylsulfate, EMpyMSO4; were synthesized in our laboratory, and their experimental densities, speeds of sound, dynamic viscosities, and refractive indices were studied as a function of temperature at atmospheric pressure. Thermal expansion coefficient, molar volume, and molar refraction of these ionic liquids were calculated from the experimental density and refractive index values. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, two LiAlH4–NaNH2 samples with LiAlH4 to NaNH2 molar ratio of 1/2 and 2/1 were investigated, respectively. It was observed that both samples evolved 2 equiv H2 in the ball milling process, however, the reaction pathways were different. For the LiAlH4–NaNH2 (1/2) sample, Li3Na(NH2)4 and NaAlH4 were formed through cation exchange between reactants. The NaAlH4 formed further reacts with Li3Na(NH2)4 and NaNH2 to give H2, NaH and LiAlN2H2. For the LiAlH4–NaNH2 (2/1) sample, Li3Na(NH2)4, LiNH2 and NaAlH4 were formed firstly through the same cation exchange process. The resulting LiNH2 reacts with the remaining LiAlH4 and produces H2 and Li2AlNH2. [ABSTRACT FROM AUTHOR]

Abstract: Polyamines are important in both prokaryotic and eukaryotic translational systems. Spermine is a quaternary aliphatic amine that is cationic under physiological conditions. In this paper, we demonstrate that spermine stimulates fMet-tRNA binding to mammalian mitochondrial 55S ribosomes. The stimulatory effect of spermine is independent of the identity of the mRNA. The degree of stimulation of spermine is the same at all concentrations of mitochondrial initiation factor 2 (IF2mt) and mitochondrial initiation factor 3 (IF3mt). This observation indicates that IF2mt and IF3mt, while essential for initiation, are not the primary components of the translation initiation system affected by spermine. IF3mt dissociates 55S ribosomes detectably in the absence of spermine, but this effect is strongly inhibited in the presence of spermine. This observation indicates that the positive effect of spermine on initiation is not due to an increase in the availability of the small subunits for initiation. Spermine also promotes fMet-tRNA binding to small subunits of the mitochondrial ribosome in the presence of IF2mt. The major effect of spermine in promoting initiation complex formation thus appears to be on the interaction of fMet-tRNA with the ribosome. [Copyright &y& Elsevier]

Abstract: The hereditary stomatocytoses (HSt) are a diverse group of conditions. Common features include hemolytic anemia, a red cell cation leak and morphological changes, but the severity of the condition can vary enormously. We have previously shown that one form of HSt (cryohydrocytosis), where the monovalent cation leak is increased at low temperature, results from amino acid substitutions in the membrane domain of band 3 (anion exchanger 1, SLC4A1). These substitutions appear to convert band 3 from an anion exchanger into a cation channel. More recently we found that over-hydrated hereditary stomatocytosis (OHSt) results from amino acid substitutions in Rh-associated glycoprotein (RhAG), a putative gas channel protein. Both band 3 and RhAG associate in the red cell membrane to form a macrocomplex that is thought to be involved in red cell gas exchange. In this paper I will review the data that has been published so far on the molecular basis of HSt. I will mention other similar conditions that cause either a cation leak or stomatocytosis or both, and consider the mechanisms of red cell shape change and permeability. [Copyright &y& Elsevier]

Abstract: This paper reports: (i) the facile synthesis of a cysteine synthon incorporating both a fluorescent group and a triphenylphosphonium derivative (TBTP) via the formation of a disulphide bond, which can subsequently undergo facile intracellular scission, (ii) the direct conjugation of this synthon to a non-permeable drug, (a cyclic PNA (peptide nucleic acid)-based compound has been chosen as a model), and (iii) that this conjugation enables the efficient homogenous delivery of the otherwise non-permeable cyclic PNA into the cytoplasm of cells, as demonstrated by fluorescence microscopy. Our results indicate that this fluorescent-labelled cysteine-TBTP synthon can provide a very useful tool for exploring the cellular uptake of a large range of molecules of biological interest, containing only a single reactive function. The preparation of an activated TBTP derivative is also described and this procedure could be widely used to introduce a TBTP cation to any thio-containing molecule. [Copyright &y& Elsevier]

Abstract: This paper tries to assess simply and quantitatively the link between classical adsorption theories and dielectric spectroscopy, in order to demonstrate that dielectric spectroscopy can be used as a tool of determination of surface energy variations due to movements of charge carriers at the surface of solids. A simple theory is developed to analyze hops of cations at the surface of mordenite, which are detected by complex impedance spectroscopy during adsorption of water. An energy of extraction of the cation can be determined from measurements and its dependence on the quantity of water molecules adsorbed is shown and qualitatively and quantitatively explained, using relationships developed in order to interpret adsorption phenomena generally. The agreement with other determinations of the adsorption energies and solid surface energy is correct. [Copyright &y& Elsevier]

Abstract: The (Na+K+S) system is of primary importance for the combustion of black liquor in the kraft recovery boilers in pulp and paper mills. A thermodynamic evaluation and optimization for the (Na+K+S) system has been made. All available data for the system have been critically evaluated to obtain optimized parameters of thermodynamic models for all phases. The liquid model is the quasichemical model in the quadruplet approximation, which evaluates 1st- and 2nd-nearest-neighbour short-range-order. In this model, cations (Na+ and K+) are assumed to mix on a cationic sublattice, while anions are assumed to mix on an anionic sublattice. The thermodynamic data of the liquid polysulphide components M2S1+n (M=Na, K and n =1–7) are fitted to ΔG = A(n)+ B(n)· T for the reaction M2S(l)+ nS(l)=M2S n+1(l). The solid phases are the alkali alloys, alkali sulphides, several different alkali polysulphides and sulphur. The solid solutions (Na,K), (Na,K)2S and (Na,K)2S2 are modelled using the compound energy formalism. The models can be used to predict the thermodynamic properties and phase equilibria in the multicomponent heterogeneous system. The experimental data are reproduced within experimental error limits for equilibria between solid, liquid and gas. The ternary phase diagram of the system (Na2S+K2S+S) has been predicted as no experimental determinations of the phase diagram have been made previously. [Copyright &y& Elsevier]

Abstract: The linear peptide gramicidin forms prototypical ion channels specific for monovalent cations and has been extensively used to study the organization, dynamics, and function of membrane-spanning channels. We have analyzed the localization of the functionally important tryptophan residues of the membrane-bound channel and non-channel conformations of gramicidin utilizing a novel dual fluorescence quenching approach [G.A. Caputo, E. London, Biochemistry 42 (2003) 3265–3274]. In this paper, we show for the first time that the dual quenching approach is applicable to multiple tryptophan containing functional ion channel peptides such as gramicidin. Importantly, dual quenching is found to be sensitive to the membrane-bound conformations of this important model ion channel. [Copyright &y& Elsevier]

Abstract: Ternary indium (III) phosphates with three-dimensional frameworks, [M 3In(PO4)2] n (M=K, ; M=Rb, ), are found and firstly reported in this paper. These compounds have been obtained by high temperature solid-state reactions and their crystal structures have been determined by single crystal X-ray diffraction analysis. The title compounds, which crystallize in monoclinic system, possess the same [In(PO4)2] n 3 n − anionic frameworks built up from interconnected InO6 octahedra and PO4 tetrahedra and have an interesting tunnel structure where M + cations are located. Optical and bonding properties of [Rb3In(PO4)2]2 are investigated in terms of measured absorption and emission spectra, and calculated band structures and density of states. The crystal band structures obtained by the DFT method show that the solid compound of [Rb3In(PO4)2]2 is an insulator with direct band gap, and the P–O covalent bond characters are larger than the In–O ones in this compound. [Copyright &y& Elsevier]

Abstract: The paper presents results of investigation of exchange of the clinoptilolite tuff cations with hydrogen ions from HCl solution of concentration 0.1 mmol cm-3 and ammonium ions solutions of concentrations 0.0071 to 2.6 mmol cm-3. Molal concentrations, x (mmol g-1) of cations exchanged in acid solution and in ammonium ions solutions were compared with molal concentrations of cations obtained by determination of the cation-exchange capacity of clinoptilolite tuff. The obtained results show that at ammonium ion concentrations lower than 0.1 mmol cm-3, with regard to exchange capacity for particular ions, best exchanged are Na+ ions, followed by Mg2+ and Ca2+ ions, while exchange of K+ ions is the poorest (Na+>Mg2+>Ca2+>K+). At ammonium concentrations from 0.2 to 1 mmol cm-3 the order is Na+>Ca2+>Mg2+>K+. At concentrations higher than 1 mmol cm-3 the order is Na+>Ca2+>K+>Mg2+. The results are a consequence of the uptake of hydrogen ions by zeolite samples in ammonium ions solutions at concentrations lower than 1 mmol cm-3 and indicate the importance of Mg2+ (besides Na+ ions) for the exchange between clinoptilolite cations and H+ ions, in contrast to K+ ions, whose participation in the reaction with H+ ions is the lowest. During decationization of the clinoptilolite in acid solution, best exchanged are Na+, Mg2+, and Ca2+ ions, while exchange of K+ ions is the poorest. Due to poor exchange of K+ and H+ ions and good exchange of Na+, Mg2+, and Ca2+ ions, it is to be assumed that preservation of stability of the clinoptilolite structure is caused by K+ ions present in the channel C. Clinoptilolite is dissolved in the clinoptilolite A and B channels where Na+, Mg2+, and Ca2+ ions are present. On the acid-modified clinoptilolite samples, exchange of ammonium ions is poorer than on natural zeolite. The longer the contact time of the zeolite and acid solution, the worse ammonium ions exchange. It can be assumed that H+ ions exchanged with zeolite cations are consumed for solution of aluminum in the clinoptilolite structure; therefore the concentration of H+ ions as exchangeable cations decreases. In the ammonium ion solution at a concentration of 0.0065 mmol cm-3, from the acid-modified zeolite samples, Al3+ ions are exchanged best, followed by Na+, Mg2+, Ca2+, and K+ ions. Further to the results, it is to be assumed that exchangeable Al3+ ions available from clinoptilolite dissolution are best exchanged with H+ ions in acid solution. [Copyright &y& Elsevier]

Abstract: The chemistry and crystal structure of tetravalent cation phosphates, including that of actinides was reviewed several times until 1985. Later, new compounds were synthesized and characterized. In more recent studies it was found that some of previously reported phases, especially those of thorium, uranium, and neptunium, were wrongly identified. In the light of these new facts, an update review and classification of tetravalent actinides phosphates is proposed in this two-part paper. Their crystal structure and some chemical properties are compared to non-actinide cation phosphates. [Copyright &y& Elsevier]

Abstract: The chemistry and crystal structure of phosphates of tetravalent cations, including that of actinides was reviewed several times up to 1985. Later, new compounds were synthesized and characterized. In more recent studies, it was found that some of previously reported phases, especially those of thorium, uranium and neptunium, were wrongly identified. In the light of these new facts an update review and classification of the tetravalent actinide phosphates is proposed in the two parts of this paper. Their crystal structure and some chemical properties are also compared to non-actinide cation phosphates. [Copyright &y& Elsevier]

Abstract: This paper reports about two new hydrogen-containing rare-earth oxoborates RE4B6O14(OH)2 (RE=Dy, Ho) synthesized under high-pressure/high-temperature conditions from the corresponding rare-earth oxides, boron oxide, and water using a Walker-type multianvil equipment at 8GPa and 880°C. The single crystal structure determination of Dy4B6O14(OH)2 showed: Pbcn, , , , , , and (all data). The isotypic holmium species revealed: Pbcn, , , , , , and (all data). The compounds exhibit a new type of structure, which is built up from layers of condensed BO4-tetrahedra. Between the layers, the rare-earth cations are coordinated by 7+2 oxygen atoms. Furthermore, we report about temperature-resolved in situ powder diffraction measurements, DTA/TG, and IR-spectroscopic investigations into RE4B6O14(OH)2 (RE=Dy, Ho). [Copyright &y& Elsevier]

In the present paper we extend our theory that calculates the fastest reaction step observable in suspensions containing charged microcrystals and heavy metal cations. The calculation requires the solution of the nonlinear Poisson–Boltzmann equation for nonsymmetric electrolytes plus the Nernst–Planck equation for transport of ions in electric fields. We find that the diffusional transport of ions to and from the surface is the rate-limiting process for our experimentally observed maximum rates. At low pH and low metal ion concentration the diffusion of metal ions is the rate-limiting step, whereas for high pH and high metal ion concentration the diffusion of the solvated protons controls the overall relaxation rate. The validity of this theory is checked for the reactions of Pb2+ and Cd2+ with goethite by means of pressure jump relaxation experiments over a wide range of temperature and pH. In all cases we observe fast processes (relaxation in the range of 103 s−1) in quantitative agreement with the theory, followed by slower processes, most probably caused by diffusion into the interior of the porous microcrystals. [Copyright &y& Elsevier]

In the process of sludge electro-dewatering (EDW), ions migration accompanied has significant influences on the dewatering efficiency. However, the effects of ions on sludge electrochemical properties and the roles in EDW are still not well understood. In this paper, influences of K+, Ca2+, and Al3+ on the mechanical dewatering and EDW process were investigated, and the mechanisms of EDW were analyzed from electrokinetic phenomena and electric conduction model. The results showed that the increase of cationic valence improved sludge mechanical dewatering but deteriorated EDW performance. The spatially distributed voltage used for ionic electromigration indicated that the lagged migration of divalent cation Ca2+ consumed more energy and reduced the dewatering rate in the later stage of EDW compared to that of monovalent cation K+. And trivalent cation Al3+ migrated less and took less water out, while it made the electrochemical reaction of EDW system easier to carry out. The decrease of the absolute zeta potential value of K+, Ca2+, and Al3+ also revealed the degeneration of dewaterability limit. An electric conduction model of partially water-saturated state porous media related to geometric factors was used and clarified the weight variation of continuous phase conductivity and surface conductivity during EDW. The results showed that the conductivity of Al-sludge was more affected by geometric factors and resulted in worse dewatering performance. This study provided a theoretical guidance for understanding the ions behavior affecting the dewatering efficiency and energy consumption of EDW. • The valent increase of cations improved mechanical dewatering but deteriorated EDW. • Electrode reaction kinetics of EDW system was analyzed. • Electromigration was analyzed from activation energy and ionic migration potential. • The action of different valent cations on conductive model of EDW was analyzed. [ABSTRACT FROM AUTHOR]

In this paper we revisit the borate systems, Sr 4-x Ba x Na(BO 3) 3 and illustrate their structural relationship with the perovskite structure. In these phases, the Na and B can be considered as forming an ordered arrangement on the perovskite small cation site, with the orientation of the oxygen atoms on the borate group such that the Na is octahedrally coordinated to O. In addition, we report the preparation of a new related solid solution series, Sr 4-x Ba x Na 1-y Li y (BO 3) 3 , showing a complete Sr/Ba solid solution series for y ​= ​0.5. Through further investigation into Ca doping into Sr 4 Li(BO 3) 3 , we have identified a new A site (Ca/Sr) ordered variant of this structure with structure refinement indicating a composition, Sr 2 · 2 Ca 1 · 8 Li(BO 3) 3. Thus, these borate systems represent interesting perovskite-type variants, with large oxygen deficiencies compared to a traditional perovskite brought about by ordered oxygen vacancies, and whose existence is dependent on cation ordering features. • Synthesis of solid solutions series Sr 4-x Ba x Na 0.5 Li 0 · 5 (BO 3) 3. • Synthesis and structure determination of new ordered Sr 2 · 2 Ca 1 · 8 Li(BO 3) 3 system. • Relatable to oxygen vacancy ordered perovskite structures. [ABSTRACT FROM AUTHOR]

All-inorganic lead-based halide perovskites have attracted great attention and interest owing to their excellent phase stability. In this paper, we have studied the effect of organic cation doping with methylammonium (MA+), formamidinium (FA+), and guanidinium (GA+) on the phase stability, electronic and optical properties of α-CsPbI 3. It is a good strategy to improve the phase stability of α - CsPbI 3 by doping organic cation, and the transition temperature is also reduced at lower temperatures. However, the incorporation of organic cations can result in the increased band gap of α-CsPbI 3 , which further leads to the reduced optical absorption coefficient. Our work may provide more theoretical guidance for the experimental researchers in search of stable photovoltaic materials. Image 1 • The phase stability of α-CsPbI 3 can be improved by doping organic cation. • The transition temperature of α-CsPbI 3 is reduced at lower temperature. • The incorporation of organic cations can increase the band gap of the α-CsPbI 3 perovskite. [ABSTRACT FROM AUTHOR]

Abstract: We describe the synthesis of cellulose fibers densely grafted with the cationic polymer poly[2-(methacryloyloxy)ethyl]-trimethylammoniumchloride (PMeDMA) through aqueous ATRP. The hydroxyl groups present on the cellulose surface were exploited to initiate the ATRP polymerization of MeDMA. We first grafted a bromide initiator, known to be an efficient initiator for ATRP, on the cellulose surface from which the polymer was then directly grown. The resulting fibers/PMeDMA complex was analyzed with infra-red, XPS and SEM techniques and present clear evidences that the polymer is present on the cellulose surface. In order to better characterize the polymer, sacrificial initiators were also added in the mixture and subsequently recovered for analysis. Size exclusion chromatography shows that the polymerization in this heterogeneous medium was controlled. Finally, we show that the mechanical properties of test hand sheets made from modified pulp are markedly improved by the grafting of the cationic PMeDMA. [Copyright &y& Elsevier]