Complete phase diagrams and physico-chemical properties for the ternary system (CsCl + NaCl + H2O) were determined at T = (298.15, 308.15, and 318.15) K, respectively. The X-ray diffraction method and Schreinemaker’s wet residue method were used to verify the solid phase. The phase diagrams show this ternary system is a complex type. Three crystallization regions were found corresponding to the single salt NaCl, a compound CsCl·2NaCl·2H2O, and a solid solution series [Cs1–x(Na·H2O)x]Cl (x in [Cs1–x(Na·H2O)x]Cl changed from 0 to 0.43 (298.15 K), 0.39 (308.15 K), and 0.36 (318.15 K) at each temperature. With rising temperature, the crystallization area of NaCl increased, but CsCl·2NaCl·2H2O and [Cs1–x(Na·H2O)x]Cl decreased simultaneously. However, density and refractive index increased with increasing CsCl concentration.

•Thermodynamic properties of RbF + Rb2SO4 + H2O and CsF + Cs2SO4 + H2O ternary systems were studied.•The exprimental data were fitted using Harned rule Pitzer model.•The activity coefficients, the osmotic coefficients, and the excess Gibbs free energy were calculated.In this paper, the potentiometric method was carried out to investigate the thermodynamic properties of the RbF + Rb2SO4 + H2O and CsF + Cs2SO4 + H2O ternary systems over total ionic strengths from (0.01–0.70) mol·kg−1 for different ionic strength fractions yB of Rb2SO4/Cs2SO4 with yB = 0.00, 0.30, 0.60 and 0.90, at 298.2 K. The Harned model and the Pitzer model were used to correlate the experimental data. The Harned coefficients and the Pitzer mixing parameters were evaluated by multiple linear regression technique. Moreover, the mean ionic activity coefficients of RbF/CsF and Rb2SO4/Cs2SO4, the osmotic coefficients, and the excess Gibbs energies of the studied systems were calculated, respectively.Thermodynamic properties, such as mean activity coefficients, osmotic coefficients and excess Gibbs free energies, of the RbF + Rb2SO4 + H2O and CsF + Cs2SO4 + H2O ternary systems were investigated by potentiometric method at 298.2 K. The Harned rule and the Pitzer model were used to correlate the experimental data.

•RhCo/CB nanohybrids are synthesized by a co-precipitation/co-reduction method.•RhCo nanocrystals show the high alloying degree and good dispersion.•RhCo/CB nanohybrids exhibit a composition-dependent catalytic activity for the MOR.•Rh3Co1/CB nanohybrids reveal the higher MOR activity than Pt/C electrocatalyst.Although both Pd and Rh fall into the Pd-group Pt-group elements (PPGEs), the electrocatalytic property of Rh nanocrystals for the methanol oxidation reaction (MOR) in alkaline media is rarely explored till now. In this work, we develop a surfactant-free co-precipitation/co-reduction method to synthesize the carbon ball supported RhCo alloy nanocrystals (RhCo/CB) nanohybrids with different Rh/Co atomic ratios and investigate their electrocatalytic acitvity for the MOR in alkaline media. Cyclic voltammetry and chronoamperometry measurements show Rh3Co1/CB nanohybrids have exceptional electrocatalytic activity and long-term stability for the MOR in alkaline media, much higher than commercial Pd/C and Pt/C electrocatalysts, demonstrating that Rh-based alloy nanocrystals may be highly promising Pt-alternative electrocatalyst for the MOR in alkaline media.Download high-res image (686KB)Download full-size image

Reduced graphene oxide (RGO)-supported Pt nanocrystal composites have wide applications in catalysis and electrocatalysis. In this work, we successfully synthesize guanidine-functionalized graphene oxide composites and phosphonate-functionalized platinum nanowires (Pt-NWs). Based on self-assembly and NaBH4 reduction, RGO-supported Pt-NW composites (Pt-NWs/RGO) are obtained successfully. The as-prepared nanomaterials are detailedly characterized using various physical techniques, such as transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, element mapping, etc. Physical characterization results demonstrate that the guanidine functionalization of graphene oxide is crucial for the generation of Pt-NW/RGO composites. Electrochemical results show that both the phosphonate functionalization of Pt-NWs and the introduction of RGO contribute to the improved electrocatalytic activity of Pt-NW/RGO composites towards the hydrazine oxidation reaction.

•BmimCl ionic liquid can react with K2PtCl4 to generate BmimCl-PtII precipitate.•Ultrafine BmimCl-PtII precipitate uniformly dispersed on the XC-72 carbon surface.•Highly dispersed Pt@BmimCl/XC-72 composites were obtained by NaBH4 reduction.•Pt@BmimCl/XC-72 composites exhibit the improved selectivity and activity for ORR.Improving the electrocatalytic activity and methanol tolerance of cathodic Pt electrocatalyst for the oxygen reduction reaction (ORR) is very important for accelerating commercial viability of direct methanol fuel cells. In this work, the highly dispersed Vulcan XC-72 carbon supported 1-butyl-3-methylimidazolium chloride (BmimCl) ionic liquid modified Pt nanoparticles (Pt@BmimCl/XC-72) composites are synthesized successfully by simple NaBH4 reduction method in the presence of BmimCl ionic liquid. In the method, the interaction between BmimCl ionic liquid and K2PtCl4 results in the generation of ultrafine BmimCl-PtII complex precipitate, which is responsible for the well dispersion and small particle size of final Pt@BmimCl/XC-72 composites. During the synthesis, the Pt nanoparticles are modified by BmimCl simultaneously due to the strong N-heterocycle-Pt interaction. The as-prepared Pt@BmimCl/XC-72 composites exhibit significantly improved activity and selectivity for the ORR in the presence of methanol in acidic media compared to Pt/XC-72 composites prepared by general NaBH4 reduction method.

•Pt nanocubes (Pt–NCs) are synthesized in diethylene glycol-ionic liquid mixture.•Introduction of ionic liquid slows the reduction rate of PtII precursor.•Adsorption of ionic liquid on Pt surface results in the formation of (100) facets.•Pt–NCs show improved electrocatalytic activity for ammonia oxidation.Well-defined Pt nanocubes (Pt–NCs) with mean diameters of 6.2 nm are synthesized successfully by a diethylene glycol (DEG) reduction route with the assistance of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) ionic liquid. The structure, size, morphology and composition of Pt–NCs are characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy, etc. Experimental characterization shows DEG serves as a reducing agent whereas [Bmim]BF4 acts as a stabilizer and structure direct agent during the synthesis of Pt–NCs. Due to the crystal facets effect, the as-prepared Pt–NCs exhibit significantly enhanced electrocatalytic activity and anti-poisoning capability for the ammonia oxidation reaction in alkaline media.Download high-res image (603KB)Download full-size image

•Activity coefficients of RbCl/CsCl in EC + H2O were determined.•Pitzer, modified Pitzer, and extended Debye–Hückel models were used.•The SLE and LLE of RbCl/CsCl + EC + H2O systems were studied.The (solid + liquid) equilibrium (SLE) and (liquid + liquid) equilibrium (LLE) of RbCl/CsCl + ethylene carbonate (EC) + H2O ternary systems were carefully investigated at 298.15 K. The SLE and LLE data were correlated by the corresponding equations respectively. Furthermore, the thermodynamic properties of RbCl/CsCl in the EC–water systems were determined by potentiometric method at T = 298.15 K. The experiment data were correlated by the Pitzer, modified Pitzer and the extended Debye–Hückel equations. The mean activity coefficients, osmotic coefficients and excess Gibbs free energies, standard Gibbs free energy of transfer and the standard solubility product of systems were calculated. The mean activity coefficient γ± decreases with the increase of the molality of electrolyte at the fixed mass fraction of EC. But γ± vary abnormally with the increase of the EC content. The result of ΔGt0 reflects the spontaneously transfer of the electrolytes from water to the mixed solvents.Thermodynamic properties, such as mean activity coefficients, osmotic coefficients and excess Gibbs free energies, of the ternary systems RbCl/CsCl + EC + H2O were determined at 298.15 K. Moreover, the (solid + liquid) equilibrium (SLE) and (liquid + liquid) equilibrium (LLE) of RbCl/CsCl + EC + H2O systems were studied at 298.15 K to maintain the homogeneity of the mixtures for potentiometric measurement.

Thermodynamic properties of the RbF + RbBr + H2O and RbF + RbNO3 + H2O systems were determined by the potentiometric method at the total ionic strengths ranging from 0.0017 to 0.7005 mol·kg–1 for different ionic strength fractions yB of RbBr/RbNO3 with yB = 0.00, 0.30, 0.60, and 0.90, at 298.2 K. Combining the Nernst equation and Pitzer equation, the mean ionic activity coefficients of RbF and RbBr/RbNO3, the osmotic coefficients, and the excess Gibbs energies of the studied systems were calculated.

The potentiometric method was used to obtain mean activity coefficients of RbF in urea/formamide–water mixed solvents at 298.2 K. The weight fractions of amide were varied from 0 to 40 %. The Pitzer, modified Pitzer and extended Debye–Hückel equations were used for representing the mean activity coefficients and other related thermodynamic properties of the systems. Furthermore, corresponding parameters of the thermodynamic models mentioned herein before were also obtained.

The (solid + liquid) equilibrium (SLE) of N,N-diethylformamide (DEF) + MCl (M = Na, K, Rb) + H2O ternary systems were investigated from 288.15 to 338.15 K under atmospheric pressure. The isothermal solubility, density, and refraction index of the ternary solution, as well as the solubility at multiple temperature were reported. The (liquid + liquid) equilibrium (LLE) of (DEF + CsCl + H2O) ternary system was further studied at 298.15 and 308.15 K. The Jouyban–Arcee model was utilized to correlate the solubility, density, and refractive index data. The LLE was correlated by the Othmer–Tobias and the Bancroft equations. The complete phase diagrams of the (DEF + CsCl + H2O) system were further presented.

•Thermodynamic properties of RbF + RbCl + H2O and CsF + CsCl + H2O ternary systems were determined.•The Pitzer model and the Harned rule were used to correlate the experimental data.•The mean activity coefficients, osmotic coefficients, and the excess Gibbs free energy were also obtained.Thermodynamic properties of (RbF + RbCl + H2O) and (CsF + CsCl + H2O) systems were determined by the potentiometric method for different ionic strength fractions yB of RbCl/CsCl at 298.2 K. The Pitzer model and the Harned rule were used to fit the experimental values. The Pitzer mixing parameters and the Harned coefficients were evaluated. In addition, the mean ionic activity coefficients of RbF/CsF and RbCl/CsCl, the osmotic coefficients, and the excess Gibbs energies of the systems studied were calculated.Thermodynamic properties, such as mean activity coefficients, osmotic coefficients and excess Gibbs free energies, of the RbF + RbCl + H2O and CsF + CsCl + H2O ternary systems were determined from potentiometric measurement at 298.2 K. The Pitzer model and the Harned rule were used to fit the experimental data.

In the present work, the density, ρ, refractive index, nD, and dynamic viscosity, η, for four binary solutions containing ionic liquids [Cnmim]X (Cnmim = 1-alkyl-3-methylimidazolium; n = 6, 8; X = Cl, Br) and ethylene glycol (EG) were investigated at temperatures of 288.15–333.15 K and at ambient pressure. In addition, the excess molar volume, VmE, was calculated and correlated using the Redlich-Kister polynomial equation. The temperature effect on the density of the binary systems studied was expressed by a linear two-parameter equation. The variation in density, refractive index, and viscosity with the composition was described by polynomial equations. The influence of carbon chain-length and the anion of the ionic liquids, and the influence of the temperature on the physicochemical properties of the binary systems can be explained by comparison of the experimental results.

Noble metal network nanostructures with three-dimensionally (3D) interconnected architectures are attracting much attention because of their unique catalytic, electrical, and optical properties. In this work, we report a facile ethylenediaminetetraacetic acid (EDTA) mediated chemical reduction route for the synthesis of high-quality palladium (Pd) nanowire networks (Pd-NWNWs). During the synthesis, EDTA interacts with PdCl2 to generate EDTA-PdII complex, which efficiently decreases the reduction potential of PdII precursor. The slow reduction rate is crucial for the generation of Pd nanowires. The morphology, composition, and structure of Pd-NWNWs are fully investigated by various physical characterizations. The electrocatalytic activity of Pd-NWNWs for the hydrazine oxidation reaction (HOR) is also studied by cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry, etc. Compared to commercial Pd black, Pd-NWNWs exhibit remarkably improved electrocatalytic activity and stability for the HOR.

•Pillar-layered 3D Zn–triazolate–carboxylate frameworks•Diverse 3,4-connected topologies tuned by the bend angles of pillars•High thermal stability and blue photoluminescenceIn the utilization of three ditopic ligands with different bend angles as pillars, we reported herein three pillar-layered Zn–triazolate–carboxylate frameworks, namely, [Zn2(ATRZ)2(BDC)]n (1), [Zn2(ATRZ)2(TPDC)]n·2nDMF (2) and [Zn2(ATRZ)2(ADDC)]n (3) (ATRZ = 3-amino-1,2,4-triazole, H2BDC = 1,4-benzenedicarboxylic acid, H2TPDC = 2,5-thiophenedicarboxylic acid, and H2ADDC = 1,3-adamantanedicarboxylic acid). Single crystal structural analyses demonstrate that different geometries of ditopic carboxylate pillars not only result in Zn–ATRZ layers adopting various corrugated configurations, but also give rise to 3,4-connected self-interpenetrated net of 1 and non-interpenetrated nets of 2 and 3. All these compounds exhibit high thermal stability and blue photoluminescence.Reported herein three 3D pillar-layered MOFs designed by appropriate selection of well-known Zn–triazolate motifs as 2D layers, and ditopic aromatic carboxylate ligands as pillars.

•Zn-1,2,4-triazolate-dicarboxylates MOFs•Porous pillar-layered framework•Remarkable H2 and CO2 gas adsorption performance•tuneable CO2/CH4 selectivityTake advantage of the readily accessible layered Zn-1,2,4-triazolate motif and two isometric dicarboxylate ligands with different functional groups (trans,trans-1,3-butadiene-1,4-dicarboxylic acid, TTBDC and 2,5-dihydroxyterephthalic acid, DOBDC), we report herein two porous Zn-triazolate-dicarboxylate pillar-layered MOFs. Flexible TTBDC led to the formation of MOF 1 crystallizing in Pna21 space group, but rigid DOBDC produced MOF 2 in P4/ncc space group. Both pillar-layered MOFs show not only remarkable H2 and CO2 uptake capacity, but also high CO2 over CH4 selectivity.Two microporous Zn-triazolate-dicarboxylate pillar-layered MOFs decorated with different functional groups exhibit not only remarkable H2 and CO2 uptake performance but also high CO2/CH4 selectivity.

Thermodynamic properties of LiCl in mixed solvents composed of polyhydric alcohols and water are measured by using the potentiometric technique at 298.15 K. The polyhydric alcohols are 1,2-propanediol (PG), 1,2-ethanediol (EG), and 1,2,3-propanetriol (GL). Pitzer and extended Debye–Hückel equations are applied to correlate the experimental data. The mean activity coefficients, the osmotic coefficients, and the excess Gibbs free energies were calculated. Meanwhile, the standard free energy of transference from water to the mixtures, the standard solubility product, and the primary LiCl hydration number are also obtained.

Thermophysical properties, such as density (ρ), refractive index (nD), and viscosity (η) of the binary systems of ionic liquids (ILs) [Cnmim]Cl (Cnmim = 1-alkyl-3-methylimidazolium; n = 2, 4) and three dipolar aprotic solvents (NMP (N-methyl-2-pyrrolidinone), DMI (1,3-dimethyl-2-imidazolidinone), and DMPU (1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone)) were measured based on the solubility of ILs in the molecular solvents at temperatures from 288.15 K to 318.15 K and the pressure of p = 0.1 MPa. Moreover, intermolecular interactions, such as weak hydrogen bonding and Coulomb forces, were discussed based on the determined properties.

•Thermodynamics of LiCl + amides (urea, NMF, DMF, DMA) + water system were reported.•The Pitzer, modified Pitzer and extended Debye–Hückel models were used.•The mean activity coefficients, excess Gibbs free energy were calculated.•The standard solubility product and the primary hydration number were obtained.This article deals with the mean activity coefficients of LiCl in amide–water mixtures with both ɛ-increasing co-solvent (urea–water, N-methylformamide–water), and ɛ-decreasing co-solvent (N,N-dimethylformamide–water, N,N-dimethylacetamide–water) systems at 298.15 K by potentiometric method. Meanwhile, thermodynamic properties including the osmotic coefficients, the excess Gibbs free energy, the standard solubility product, the primary LiCl hydration number and the standard free energy of transference from water to the mixtures were also calculated. The nonideal behavior of these systems has been discussed in terms of the Pitzer, the Modified Pitzer and the extended Debye–Hückel equations parameters.The thermodynamic properties of LiCl in amide–water mixtures with both ɛ-increasing co-solvent (urea–water, N-methylformamide–water), and ɛ-decreasing co-solvent (N,N-dimethylformamide–water, N,N-dimethylacetamide–water) systems at 298.15 K were determined by potentiometric method.

The solubilities, densities and refractive indices for the four ternary systems ethylene glycol/glycerin+RbNO3/CsNO3+H2O were measured with mass fractions of ethylene glycol or glycerin in a range of 0 to 1.0 at 288.15 and 298.15 K. In all the cases, the presence of either ethylene glycol or glycerin significantly reduces the solubilities of the rubidium nitrate and cesium nitrate in aqueous solution, but the refractive indices increase with the increase of mass fraction of either ethylene glycol or glycerin. The density, refractive index and solubility of the saturated ternary systems were correlated with each other via polynomial equations. In addition, the refractive indices and densities of unsaturated solutions were also determined for the four ternary systems with different salt concentrations, which were correlated with the salt concentration and proportion of ethylene glycol or glycerin in the solution.

Density ρ, refractive index nD, and viscosity η for ionic liquids [Cnmim]Cl (Cnmim = 1-alkyl-3-methylimidazolium; n = 2, 4, 6, 8 for ethyl, butyl, hetyl, and octyl) + N,N-dimethylformamide (DMF) binary systems have been investigated at atmospheric pressure from 288.15 K to 318.15 K. The molar excess Gibbs energy ΔG*E, volumetric properties including excess molar volume VE, and apparent molar volume Vφ,i have been calculated from the experimental data. Furthermore, the refractive index and viscosity deviations (ΔnD, Δη) from the ideal behavior have been obtained and well fitted to the Redlich–Kister equation. Our results show that DMF can effectively adjust the physicochemical properties of 1-alkyl-3-methylimidazolium ionic liquids.

We report herein the solid–liquid equilibria (SLE) of N,N-dimethylacetamide (DMA) + MCl (M = Na, K, Rb, and Cs) + H2O ternary systems for the first time. At the three given temperatures (T = 298.15 K, 308.15 K, and 318.15 K), the solubilities, densities, and refractive indices for these ternary systems are determined with the mass fraction of DMA in salt-free solvent system ranging from 0.0 to 1.0. The solubility of salts decreases significantly with the addition of DMA, and the salting-out ratios are calculated accordingly. The nonrandom two-liquid (NRTL) model can effectively fit the experimental solubility. Furthermore, to investigate the temperature effect on the SLE, the dynamic solubility measurement system is selected to determine the solubility of the salts in the mixed solvent (wDMA = 0.3, 0.5, and 0.7) with the temperature continuously increased. The solubility data at multiple temperatures are well fitted by the modified Apelblat equation and the λh equation.

The solubility, density and refractive index of RbCl/CsCl + [Cnmim]Cl (n = 2, 4, 6, 8) + H2O saturated systems have been studied at T = (288.15, 298.15 and 308.15) K. The solubility data were correlated by the nonrandom two-liquid (NRTL) model and an empirical equation. Both models can qualitatively represent the equilibrium behavior. In addition, the results denote that all the ionic liquids trigger salting-out effects with the order: [C2mim]Cl > [C4mim]Cl > [C6mim]Cl > [C8mim]Cl. The density and refractive index of the saturated solutions were determined for describing the relationship between the physical property and composition of the solution.

This article reports mean activity coefficients determined by the potentiometric method for RbF and CsF in alanine/proline/serine + water mixtures at 298.15 K. The experimental results were modeled by the Pitzer, modified Pitzer, and extended Debye–Hückel equations. The results showed that the three models fit the experimental data well and gave satisfactory results. The osmotic coefficients, excess Gibbs free energy, and corresponding parameters were also obtained.

•ATPS of ionic liquids + Rb2CO3/Cs2CO3 + H2O.•The binodal curves were fitted using a three-parameter equation.•The tie-lines were correlated by the Othmer–Tobias and Bancroft equations.•The different effecting factors on the ATPS were investigated.This work was devoted to propose a series of novel aqueous two-phase systems (ATPSs) composed of 1-alkyl-3-methylimidazolium bromide + Rb2CO3/Cs2CO3 + water ([C2mim]Br = 1-ethyl-3-methylimidazolium bromide, [C3mim]Br = 1-propyl-3-methylimidazolium bromide, [C4mim]Br = 1-butyl-3-methylimidazolium bromide, [Amim]Br = 1-allyl-3-methylimidazolium bromide). The phase behavior of these ATPSs had been experimentally determined at T = 288.15 K < T < 308.15 K. In particular, the effects of the ionic liquid structure, temperature and the types of inorganic salts on the phase equilibrium of ATPSs have been discussed in detail. The binodal curves were fitted by a three-parameter equation. The tie-lines were correlated by the Othmer–Tobias and Bancroft equations.The phase behavior for a series of aqueous two-phase systems composed of 1-alkyl-3-methylimidazolium bromide + Rb2CO3/Cs2CO3 + water had been experimentally determined in the temperature range of 288.15–308.15 K.

The mean activity coefficients for CsCl in N-methylformamide or urea (w) + H2O (1 − w) systems were determined in this work by potentiometry, using ion-selective electrodes at 298.15 K. The value of mass fraction w was varied between 0.00 and 0.40 in five unit-steps and the molality of CsCl was between 0.0020 and 1.4009 mol·kg−1. The experimental data have been correlated with the Pitzer, modified Pitzer and the extended Debye–Hückel equations. The resulting values of the mean activity coefficients, the osmotic coefficients and the standard Gibbs energy of transfer, together with the Pitzer ion-interaction parameters (β(0), β(1) and Cφ), extended Debye–Hückel parameters (a, c and d), and modified Pitzer parameters (b, BMX, CMX) are reported for the investigated systems.

In this work, it was found that some monosaccharides normally used to stabilize enzymes at high temperatures, however, actually caused a deactivation of chloroperoxidase (CPO). The red native CPO was converted to a stable pale species that lost enzymatic activity. This deactivation was irreversible and was sensitive to temperature. It was different from the general peroxide-mediated deactivation of CPO.Data from measurement of chlorination activity as well as UV–vis, fluorescent, and CD spectral analysis indicated that monosaccharide-induced deactivation can be attributed to precipitation of protein in the presence of monosaccharide and the interaction of the aldehyde group of sugar with amino groups, especially the terminal amino group, on proteins to form Schiff bases which then rearrange to the stable amino ketone.It is further noted that the deactivation efficiency depends on the stereostructure of monosaccharides. d-Glucose was the most efficient inactivating agents due to its aptitude for both of the interactions mentioned in the above paragraphs. The deactivation was specific to aldose. No deprivation of the heme iron was involved in this deactivation.Graphical abstractHighlights► Monosaccharides could cause a suicide inactivation of chloroperoxidase (CPO). ► The sixth axial ligand position of heme iron was occupied by monosaccharides. ► Absorption of Soret band decreased due to occurrence of precipitation of protein. ► Fluorescent and CD spectral analysis indicated a minor uncoiling of α-helix occurred. ► The stereostructure of monosaccharide is related with this enzymatic inactivation.

This article deals with the mean activity coefficients of RbF or CsF in the glycine + water mixed systems. The Pitzer, the modified Pitzer, and the extended Debye–Hückel equations are used to describe the nonideal behavior of the electrolyte. The osmotic coefficients, the excess Gibbs free energy, and the standard Gibbs energies of transfer were calculated with the corresponding parameters.

In this paper, the mean activity coefficients for CsBr, as well as the osmotic coefficients, the excess Gibbs free energies, the Gibbs energies of transference, and the primary hydration in different MeOH–water and EtOH–water mixtures at 298.15 K are calculated by potentiometric measurements. The cell used in this work contains two ion selective electrodes (ISEs): Cs-ISE|CsBr(m), ROH(w), H2O(1 – w)|Br-ISE (R = Me and Et), and the mass fraction of ROH in the mixture (w) was varied between 0 and 0.3 in 0.1 unit steps. The experimental data were correlated very well by the thermodynamics equations of Pitzer, modified Pitzer, and Debye–Hückel models.

Two novel complexes constructed from the sulfonamide Schiff base ligand H2L, N-[2-(5-bromo-2-hydroxybenzylideneamino)ethyl]-4-methylbenzene-sulfonamide, [Cu(HL)2] (1) and [CuL(H2O)] (2) are synthesized and characterized via X-ray single-crystal diffraction, elemental analysis, FT-IR and UV–Vis. 1 and 2 both form 1-D supramolecular architectures by π–π stacking interactions. 1 and 2 both crystallize in monoclinic, with space group C2/c and P2/c for 1 and 2, with unit cell parameters a = 27.640(18) Å, b = 7.907(5) Å, c = 17.945(14) Å, β = 118.27(2)°, V = 3454(4) Å3, Z = 4 for 1, and a = 16.758(5) Å, b = 7.272(2) Å, c = 15.080(4) Å, β = 106.334(5)°, V = 1763.6(9) Å3, Z = 4 for 2.

Solubilities, densities, and refractive indices have been measured for the four ternary systems, ethylene glycol + NaCl + H2O, ethylene glycol + KCl + H2O, ethylene glycol + RbCl + H2O, and ethylene glycol + CsCl + H2O, at T = 298.15 K, with mass fractions of ethylene glycol ranging from 0 to 1.0. Polynomial equations of fit are proposed for the solubility of the saturated solutions as a function of the mass fraction of ethylene glycol. The equations proposed also account for the density and refractive index for the saturated solutions. On the other hand, the density and refractive index of unsaturated solutions were also determined for the same ternary systems with varied undersaturated salt concentrations. Values for both the properties were also correlated with the salt concentrations and proportions of ethylene glycol in the undersaturated solutions. In all the cases, the presence of ethylene glycol significantly reduces the solubility of the salts in the aqueous solution.

The mean activity coefficient of RbCl or CsCl in N,N-dimethylformamide (DMF) + water mixtures was determined by potentiometric measurements at 298.15 K in the range w = 0.10 to 0.40 DMF. The Pitzer model was adopted to describe the behavior of the electrolytes. We also obtained the osmotic coefficients and the Gibbs energies of transfer of rubidium or cesium chloride from water to DMF + water mixtures.

Liquid−liquid equilibria for the two ternary systems of CH3OH + Rb2CO3 + H2O and CH3CH2OH + Rb2CO3 + H2O were measured at T = (298.15, 308.15, and 318.15) K. Binodal curves, tie-lines, and integrated phase diagrams for the two ternary systems are given. The experimental binodal curve data are correlated using a three- parameter equation, and the tie-line data are corrected by the Othmer−Tobias and Bancroft equations. The salting-out effect of ethanol is greater than that for methanol, but the effect of temperature on the equilibrium was not significant.

•The ternary system (NaCl + RbCl + H2O) at T = (288.15, 298.15 and 308.15) K.•The stable (solid + liquid) phase equilibrium was achieved.•The solid phases were determined by Schreinemaker’s wet residue and X-ray diffraction method.The (solid + liquid) phase equilibrium of the ternary system (NaCl + RbCl + H2O) at T = (288.15, 298.15 and 308.15) K was studied by the method of isothermal solution saturation. Moreover, the density and refractive index of the solution was also determined. The solid phase was studied by the Schreinemaker’s wet residue method and verified by X-ray diffraction. The results show that each of the phase diagrams contains one invariant point, two univariant curves, and three crystallization regions. The crystallization region of NaCl increased obviously with the temperature increasing, while the crystallization regions of RbCl and the mixed crystallization region of (NaCl + RbCl) decreased a little. Furthermore, there are break points at the invariant points for density and refractive index curves.

Biotransformation of cyclohexene catalyzed by chloroperoxidase (CPO) from Caldariomyces fumago was employed to prepare value-added oxygenated derivative: trans-1,2-cyclohexanediol (CHD) using H2O2 as oxidants. The conversion of substrate was enhanced to 89.2% in the presence of small quantities of quaternary ammonium salts (QAS) compared to that of only 48.1% in aqueous phosphate buffer after 150 min. The enhancement was dependent on the concentration and alkyl group length of QAS. QAS were found playing multiple functions in reaction media: phase transfer catalysis and tuning the composition of product. UV–vis, fluorescence and circular dichroism (CD) spectral assay were employed to investigate the effect of QAS on micro-environment around active center and structure of protein. The strengthening of α-helix structure of CPO and more exposure heme for easily access of substrate was found responsible for the improvement of catalytic performance of CPO. Moreover, the determined kinetic parameters indicated the affinity and selectivity of CPO to substrate was improved according to the observation of a decrease of Michaelis constant Km while an increase of the second order rate constants kcat/Km.The strategy reported in this work is environment-friendly, straightforward and applicable to large scale preparation.Graphical abstractDownload high-res image (192KB)Download full-size imageHighlights► Cyclohexene was turned to value-added derivative by CPO-catalyzed biotransformation. ► Small quantity of introduced quaternary ammonium salts played multiple functions. ► The strategy is environment-friendly, straightforward and applicable to large scale.

Reduced graphene oxide (RGO)-supported Pt nanocrystal composites have wide applications in catalysis and electrocatalysis. In this work, we successfully synthesize guanidine-functionalized graphene oxide composites and phosphonate-functionalized platinum nanowires (Pt-NWs). Based on self-assembly and NaBH4 reduction, RGO-supported Pt-NW composites (Pt-NWs/RGO) are obtained successfully. The as-prepared nanomaterials are detailedly characterized using various physical techniques, such as transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, element mapping, etc. Physical characterization results demonstrate that the guanidine functionalization of graphene oxide is crucial for the generation of Pt-NW/RGO composites. Electrochemical results show that both the phosphonate functionalization of Pt-NWs and the introduction of RGO contribute to the improved electrocatalytic activity of Pt-NW/RGO composites towards the hydrazine oxidation reaction.