Aqueous Chloride Solutions Research Articles

Mass spectrometry of complex compound of bis-thiourea-lead (II) chloride

Complex compounds of lead salts and thiourea are of interest due to the possibility of their practical application as precursors in the deposition of metal sulphide films. It is relevant to establish the relationship between the composition and structure of the initial complex compounds and the structure of the sulphides formed as a result of their thermal destruction. This paper presents the results of studying the complex compounds formed in an aqueous solution of lead chloride and thiourea. The structure of the complex compounds was determined by matrix-assisted laser desorption/ionisation mass spectrometry. The mass spectrometry data confirmed the formation of the [Pb((NH2)2CS)2Cl2] complex in the solution, which is a precursor in the deposition of PbS films. It was demonstrated that mass spectrometry fragmentation of the molecular ion of the [Pb((NH2)2CS)2Cl2] compound leads to the formation of a lead sulphide ion. The obtained data confirm the formation of the lead-sulphur bonds in the inner sphere of the complex compound, which are fragments of the crystal structure of the prospective sulphide formed during the thermolysis of the complex.

Optical property measurements of lithium chloride aqueous solution for a novel solar neutrino experiment

The lithium chloride aqueous solution has great potential to be the detection medium of a novel solar neutrino detector. The nuclide 7Li provides a charged-current interaction channel with a high cross-section for the MeV-scale solar electron-neutrinos, enabling measurement of the solar neutrino spectrum. This work measures the optical properties and the light yields of a saturated lithium chloride solution. After adsorption with activated carbon and recrystallization, the solution shows little absorption in the sensitive wavelength range of the bialkali photomultipliers. The attenuation length is evaluated to reach 50 meters at 430 nm. In addition to being a pure Cherenkov detector medium, a wavelength shifter, carbostyril 124, is added to the LiCl aqueous solution. The compatibility and the enhancement of the light yield are confirmed, enabling the development of a water-based Cherenkov-enhanced lithium-rich detector.

High performance of graphene oxide (GO)-thiosemicarbazide (TSC) modified membrane for pervaporation desalination with TSC performed as a novel cross-linker

Graphene oxide (abbreviated as GO)-based membranes have shown tremendous potential for desalination. Nevertheless, it is still a major challenge to adjust the interlayer spacing of GO nanosheets and suppress their swelling in aqueous solution to achieve excellent separation properties. Herein, using ceramic membrane as substrate, thiosemicarbazide (TSC) was creatively used to cross-link with GO to tune the interlayer spacing of GO nanosheets. Through vacuum filtration, the GO-TSC modified membrane (abbreviated as GO-TSC membrane) was prepared and was subsequently used for pervaporation (PV) desalination. Results indicated the GO-TSC membrane exhibited a robust structure and presented great desalination performance with the water flux of 6.01 L/(m2·h) and the corresponding salt rejection of over 99.90 % towards 3.5 wt % sodium chloride aqueous solution at 60 °C. This work provides a novel strategy in the way of preparing GO-based membranes for PV desalination.

Magnesium nanoparticles as a highly stable anode for the electrochemical cell

The chemical route for synthesis of magnesium nanoparticles serving as an active material for the nanocomposite anode with the conductive polymeric matrix is described. The electrochemical characteristics of the produced anode is investigated and compared with those of the counterpart anode made of micro-scale Mg particles. The energy density at 10 mA for the anode incorporating Mg nanoparticles (169.1 ± 10.8 W∙h/kg) is 6.8 times higher than that for the anode with Mg microparticles (24.8 ± 6.7 W∙h/kg). It is shown that the nanocomposite anode possesses superior stability and discharge voltage in potassium chloride aqueous solution with respect to that incorporating coarse particles. High discharge voltage is kept due to the uniform distribution of agglomerates of Mg nanoparticles in the anode. Using the results of Fourier-transform infrared spectroscopy it is suggested that the high resistance to oxidation of anode with Mg nanoparticles can be the root-cause of the enhanced electrochemical performance of the anode.

Transport Properties of Carbohydrates: Towards the Minimization Toxicological Risks of Cobalt and Chromium Ions

The influence of oligosaccharides (α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin), and a polysaccharide, sodium hyaluronate (NaHy), on the diffusion of aqueous solutions of cobalt and chromium chlorides has been investigated. Cobalt and chromium are constituents of metal alloys for biomedical use, including dental prostheses. Thus, the release of these ions in the human body can lead to harmful biological effects. The interaction of metal ions with saccharides might have information on the role of mouthwashes in preventing these effects. This interaction has been assessed by measuring multicomponent intermolecular diffusion coefficients at 298.15 K. It has been found that β-cyclodextrin has the highest interaction towards cobalt and chromium ions. This work will contribute to unveiling the mechanisms responsible for transport by diffusion in aqueous solutions, and, therefore, mitigating the potential toxicity inherent to those metal ions.

Structure of the Nearest Environment of Ions in Aqueous Solutions of Cadmium Chloride and Nitrate According to the Data of X-ray Diffraction Analysis

Quantitative characteristics of the nearest environment of ions in aqueous solutions of cadmium chloride and nitrate are determined by X-ray diffraction analysis in a wide range of concentrations under standard conditions. It is found that, in the studied systems, the coordination number of the cation increases with dilution from 4 to 6. The structure of solutions in the entire studied range of concentrations is determined by ionic associates of the contact type. In solutions of cadmium nitrate, the nitrate ion is monodentately coordinated to the cation.

Structure of the Nearest Environment of Ions in Aqueous Solutions of Cadmium Chloride and Nitrate According to the Data of X-ray Diffraction Analysis

Structure of the Nearest Environment of Ions in Aqueous Solutions of Cadmium Chloride and Nitrate According to the Data of X-ray Diffraction Analysis

Tri(ethylene glycol) modified HYC‐100 resin for lithium ion recovery from aqueous solution

AbstractPolymeric resin has shown great application in recovery the lithium ion from aqueous solution due to their structure's tunability and reusability. However, the conventional resins such as commercial HYC‐100 is suffering by its low lithium adsorption capacity and slow inclusion rate. Herein, a series of HYC‐100 modified resins (MRs) using oligo(ethylene glycol) as crosslinker were synthesized and their adsorption capacities for lithium ion in aqueous solution (pH 9.1, ionic concentration 500 mg/L, 25°C) were determined by adding 1 g resin to 500 mL lithium chloride aqueous solution. The new formed cyclic structure from oligo(ethylene glycol) provides lithium ion binding sites which play an important role for lithium ion adsorption. The tri(ethylene glycol) modified resin (3EGMR) showed the highest capacity to be 18 mg/g, which was three times more than that of HYC‐100 (5 mg/g). Therefore, Scale‐up experiment was conducted by using 20 L reactor and the adsorption capacity is satisfactory. This work might pave a new avenue to develop new polymeric resin to enhance the lithium ion adsorption performance.

A Template-Free Pd2 L4 Cage with up to Nanomolar Affinity for Chloride in Aqueous Solutions.

Invited for the cover of this issue is the group of Dillip Kumar Chand at the Indian Institute of Technology Madras. The image depicts the efficient chloride binding ability of a designer self-assembled coordination cage in water. The binding occurs selectively even in presence of models of biologically abundant anionic systems. Read the full text of the article at 10.1002/chem.202300891.

Effect of salt addition on cellulose conversion into 5-hydroxymethylfurfural in metal chloride aqueous solution

Metal chloride aqueous solution is an effective method to promote the conversion of cellulose into 5-hydroxymethylfurfural (HMF). In this work, the influences of sodium chloride (NaCl) and lithium chloride (LiCl) on the conversion of cellulose into HMF in ferric chloride (FeCl3) aqueous solution were investigated. The conversion of glucose and fructose in FeCl3–NaCl and FeCl3–LiCl aqueous solutions were studied, and the interaction between active species and cellobiose was characterized by UV spectrum and electrospray ion mass spectrometry to explore salt addition on the reaction of cellulose conversion and the active specie. Results showed that the yield of HMF converted from cellulose in FeCl3 aqueous solution was low, while the yield of HMF was significantly increased when NaCl or LiCl added to the system. In FeCl3–NaCl aqueous solutions, the yield of HMF reach a maximum of 40.0% at a concentration of 0.02 M FeCl3, and hydrolysis of cellulose was the key step in the conversion of cellulose; In FeCl3–LiCl aqueous solutions, the yield of HMF reach a maximum of 36.7% at a concentration of 0.06 M FeCl3, and isomerization of glucose was the controlling step. The characterization results illustrated that the addition of NaCl or LiCl changed the active species in FeCl3 aqueous solutions, and [Fe(OH)2]+ and [FeCl2(OH) + Li]+ were the active species in FeCl3–NaCl and FeCl3–LiCl aqueous solution for cellulose conversion, respectively.

Temperature dependent volumetric, viscometric and conductance studies of barium chloride in aqueous solution of citric acid: an insight into molecular interactions

Abstract Alkaline earth metal salts and citric acid both play a vital role in our daily life in terms of biological importance, so in this regard, in the present study, we calculated density, speed of sound, conductance and viscosity of barium chloride (BaCl2) in concentration range (0.01–0.12 mol kg−1) in a binary solution of 0.01 mol kg−1 citric acid in water (CA + H2O) at temperatures between 303.15 and 318.15 K with gap of 5 K. The various parameters like apparent molar volume ϕ v , limiting apparent molar volume ϕ v o , transfer volume Δ tr ϕ v o , and partial molar volume expansibilities Φ E o ${{\Phi }}_{E}^{o}$ were calculated using density data. Viscosity data has been applied to calculate relative viscosity and Jones Dole coefficient A and B. Other parameters like Molar conductance (Λ m ), Λ o m and Λ o m η o have also been calculated using conductance data. All these parameters show strong evidences of various molecular interactions in terms of ion–solvent and solute–solute interactions. The ion–solvent interactions were supported by isobaric thermal expansion coefficient α o . Structure maker/breaker behaviour is explained by Hepler’s constant ((d 2 ϕ v o /dT 2 ) p ), temperature coefficient of B ( d B / d T $dB/dT$ ) and Walden product’s temperature coefficient (d(Λ o m η o )/dT). Further these molecular interactions support structure breaking potential of present studied system.

Phase Diagram of Aqueous Solutions of LiCl: a Study of Concentration Effects on the Anomalies of Water

We perform molecular dynamics simulations in order to study thermodynamics and the structure of supercooled aqueous solutions of lithium chloride (LiCl) at concentrations c = 0.678 and 2.034 mol/kg. We model the solvent using the TIP4P/2005 potential and the ions using the Madrid-2019 force field, a force field particularly suited for studying this solution. We find that, for c = 0.678 mol/kg, the behavior of the equation of state, studied in the P-T plane, indicates the presence of a liquid-liquid phase transition, similar to what was previously found for bulk water. We estimate the position of the liquid-liquid critical point to be at Tc ≈ 174 K, Pc ≈ 1775 bar, and ρc ≈ 1.065 g/cm3. When the concentration is tripled to c = 2.034 mol/kg, no critical point is observed, indicating its possible disappearance at this concentration. We also study the water-water and water-ions structure in the two solutions, and we find that at the concentrations examined the effect of ions on the water-water structure is not strong, and all the features found in bulk water are preserved. We also calculate the hydration number of the Li and Cl ions, and in line with experiments, we find the value of 4 for Li+ and between 5.5 and 6 for Cl-, confirming the good performances of the Madrid-2019 force field.

Dynamics of a methane hydrophobe in aqueous choline chloride solution: Insights from molecular dynamics simulations

Motion of hydrophobic moieties in solvent plays a crucial role in biomolecular functioning and is strongly influenced by the properties of the surrounding environment. To have a molecular-level picture of the dynamics of tiny hydrophobes, we simulate a methane molecule in different concentrations of aqueous choline chloride (ChCl) solution. Our analyses reveal slower translational dynamics of methane and the emergence of spatiotemporal heterogeneity at the timescales across which methane shows cage and jump motion. This results non-Gaussianity in the dynamics and it becomes increasingly pronounced with higher ChCl concentration. This illustrates more confined motion of methane inside the smaller and closely spaced cages. Hence, the jump percentage increases, and the jump length decreases. However, the maximum contribution to total diffusion comes from residual diffusion, which accounts for caging and small step displacements.

Vapor-liquid-solid equilibria and thermodynamic study of aluminum chloride aqueous solutions at various temperatures

The vapor-liquid-solid equilibria and thermodynamics data relevant to aluminum chloride in aqueous solutions were investigated at various temperatures. The water activity measurements of AlCl3(aq) were carried out from dilution to saturated solutions at temperatures ranging from 298.15 to 353.15 K using the hygrometric method. From new experimental results, the ion interaction of Pitzer, extended ion interaction (EII) and Clegg–Pitzer–Brimblecombe (CPB) models were developed to allow the parametrization of the binary system. The interaction parameters were evaluated for the Al−Cl−H2O system and used to calculate the solute activity and osmotic coefficients form the three models. The standard approach for a 3–1 electrolyte with the ion parameters in the temperature range shows a very good agreement with osmotic coefficient data for unsaturated solutions. The solubility equilibrium of anhydrous AlCl3 in aqueous solutions was determined experimentally up to mmax=(3.383 to 3.606) mol·kg−1from (298.15 to 353.15) K respectively; then, the solubility products as LnKsp∘ of AlCl3(aq) were also given using the obtained activity coefficients at various temperatures.

Elucidation of electrochemical and morphological difference of carbon steel corroded in aqueous chloride solutions at low temperatures

Elucidation of electrochemical and morphological difference of carbon steel corroded in aqueous chloride solutions at low temperatures

A Template-Free Pd2 L4 Cage with up to Nanomolar Affinity for Chloride in Aqueous Solutions.

Selective binding of chloride over the other most abundant anions in living organisms is pivotal due to its essential role in physiological functions. Herein, we report a template-free Pd2 L4 cage exhibiting high selectivity for medium-sized halides (i. e., Cl- , Br- ) in water owing to the size-discriminatory nature of the cage cavity. In pure water, this cage displays high selectivity and micromolar affinity for chloride. The cage shows no binding towards other biologically more abundant essential anions such as phosphates, carboxylates, or bicarbonate. This cage shows an unprecedented nanomolar affinity with 1 : 1 binding stoichiometry for chloride in aqueous-DMSO media. This high affinity was achieved with the best use of traditional hydrogen bonding and electrostatic interactions, as confirmed by single-crystal X-ray diffraction analysis. This well-defined cage sequestrates F- by cleaving a B-F bond in BF4 - in a facile manner in a nonpolar solvent or in the presence of excess ligand. This cage also demonstrates capture of the sub-ppm chloride level that is present in commercial D2 O samples.

Fast and Selective Degradation of Biomass for Xylose, Glucose and Lignin under Mild Conditions.

The conversion of lignocellulose into valuable chemicals has been recognized as the key technology in green chemistry. However, selective degradation of hemicellulose and cellulose with the production of lignin is still a challenge. Therefore, a two-step process has been developed to degrade corncob into xylose and glucose under mild conditions. At first, the corncob was treated with the lower concentration of zinc chloride aqueous solution (30-55 w%) at 95 °C with a short reaction time (8-12 min) and 30.4 w% (selectivity = 89%) of xylose obtained with a solid residue of the composite of cellulose and lignin. Next, the solid residue was treated with a high concentration of zinc chloride aqueous solution (65-85 w%) at 95 °C for about 10 min, and 29.4 w% (selectivity = 92%) of glucose can be obtained. Combining the two steps, the total yield of xylose is 97%, while glucose is 95%. In addition, high pure lignin can be obtained simultaneously, which was confirmed using HSQC studies. Furthermore, for the solid residue of the first-step reaction, a ternary deep eutectic solvent (DES) (choline chloride/oxalic acid/1,4-butanediol, ChCl/OA/BD) has been used to separate the cellulose and lignin efficiently, and high-quality cellulose (Re-C) and lignin (Re-L) were obtained. Furthermore, it provides a simple method to disassemble the lignocellulose for monosaccharides, lignin, and cellulose.

SYNTHESIS AND CHARACTERIZATION OF SOME NEW NITRONES DERIVATIVES AND SCREENING THEIR BIOLOGICAL ACTIVITIES

Synthetic approached towards the synthesis of some novel nitrones derivatives have been started with reduction of nitrobenzene derivatives as starting material bearing electron withdrawing and electron donating groups to corresponding phenylhydroxylamine in presence of zinc dust as reducing agent in aqueous solution of ammonium chloride (NH4Cl). The prepared phenylhydroxylamine derivatives were reacted with different substituted benzaldehydes to give the target derivatives of nitrone. The structures of the synthesized nitrones were characterized by spectroscopic methods FT-IR, 1H-NMR and 13C NMR. Finally, the newly synthesized compounds were screened for their microorganism activities at different concentration, and inhibited growth of Escherichia coli (E. coli) Gram negative, Staphylococcus aureus (S. aureus) Gram positive, and fungi (candida albicans).

Dynamics of Concentrated Aqueous Lithium Chloride Solutions Investigated with Optical Kerr Effect Experiments

We report the dynamics of concentrated lithium chloride aqueous solutions over a range of moderate to high concentrations. Concentrations (1-29 to 1-3.3 LiCl-water) were studied in which, at the highest concentrations, there are far too few water molecules to solvate the ions. The measurements were made with optically heterodyne-detected optical Kerr effect experiments, a non-resonant technique able to observe dynamics over a wide range of time scales and signal amplitudes. While the pure water decay is a biexponential, the LiCl-water decays are tetra-exponentials at all concentrations. The faster two decays arise from water dynamics, while the slower two decays reflect the dynamics of the ion-water network. The fastest decay (t1) is the same as pure water at all concentrations. The second decay (t2) is also the same as that of pure water at the lower concentrations, and then, it slows with increasing concentration. The slower dynamics (t3 and t4), which do not have counterparts in pure water, arise from ion-water complexes and, at the highest concentrations, an extended ion-water network. Comparisons are made between the concentration dependence of the observed dynamics and simulations of structural changes from the literature, which enable the assignment of dynamics to specific ion-water structures. The concentration dependences of the bulk viscosity and the ion-water network dynamics are directly correlated. The correlation provides an atomistic-level understanding of the viscosity.

Thermodynamic Study of the Activity of Cadmium Chloride in Aqueous Solutions at Various Temperatures

The thermodynamic properties of cadmium chloride in aqueous solutions were investigated by the hygrometric method and thermodynamic modeling at different temperatures. The water activities were measured in the molality range from 0.10 mol·kg–1 up to mmax = (6.60 to 7.65) mol·kg–1 at temperatures from 298.15 to 353.15 K, respectively. From the newly measured data, the osmotic coefficients of water were deduced. The cadmium chloride aqueous solutions contain some additional complexes such as CdCl2(aq), Cd2+(aq), CdCl+(aq), CdCl3–(aq), and CdCl42–(aq). Based on emf data of the literature for CdCl2(aq) at 298.15 K, the consistency of the activity coefficient was evaluated using an adequate model. The parametrizations were developed by the ion interaction models, and the Filippov–Charykov–Rumyantsev model is the only one that gives a better representation of the experimental results with excellent prediction of the activity coefficients. This procedure is extended to obtain the recommended activity coefficients at various temperatures. The water activities, activity coefficients, and molalities of the saturated points were used to calculate the solubility product and the Gibbs energy of dissolution at different temperatures. The calculated ΔGdiss° was compared with that existing in the literature at 298.15 K, and good agreement is obtained.