Dissolution Of Chloride Research Articles

Dissolution and intrusion of chloride disrupted biodegradation products to persistently accelerate biodegradation of Fe-based implants

The biodegradation of Fe is severely limited due to barrier of biodegradation products. Herein, NaCl was introduced into Fe matrix and results demonstrated that NaCl significantly accelerated biodegradation rate of Fe. It was ascribed that (i) NaCl in Fe matrix initially dissolved to produce biodegradation active sites, (ii) Cl- with small ionic radii invaded the biodegradation product layer, and (iii) abundant Cl- greatly promoted the anode process of Fe biodegradation. Additionally, Fe-NaCl biocomposites also exhibited favorite cytocompatibility. These results demonstrated great potential of NaCl in accelerating the persistent biodegradation of Fe for load-bearing implants.

A Screen-Printed Potentiometric Sensor for Stability Indicating Assay and Real-Time Monitoring of Trospium Chloride Dissolution Profile in its Pharmaceutical Dosage Form

According to FDA guidance, a biowaiver concept declares that dissolution testing could be approved as a replacement strategy for bioequivalence studies and/or in vivo bioavailability. From the analytical chemistry standpoint, the shift from the classically developed offline methods to the highly integrated miniaturized inline analyzers is one of the pioneering ways that would modernize future of in-vitro - in-vivo correlation (IVIVC). The emergence of screen-printed electrodes (SPE) is now making the move from successive sampling steps and off-line measurements to real-time and in-line monitoring. Recently, “SPE” potentiometric sensor was presented as real-time analyzer that can offer similar analytical results as separation-based chromatographic techniques. Thus, the main objective of this paper is to design a real-time SPE for in situ monitoring of the dissolution of trospium chloride (TRO) in neutral media. Validation of the proposed sensor was performed according to the IUPAC commendations. The measurements performed with this sensor showed an accuracy of average recovery 100.50% and standard deviation of less than 1.0%, also the repeatability and intermediate electrode variabilities were less than 1.0 and 1.3%, respectively. The developed sensor was successfully used for direct observation of the dissolution profile without any need for an extraction step or sample preparation.

Solvation of magnesium chloride dimer in water: The case of anionic and neutral clusters.

The structures of magnesium chloride dimer-water clusters, (MgCl2)2(H2O)n-/0, were investigated with size-selected anion photoelectron spectroscopy and theoretical calculations to understand the dissolution of magnesium chloride in water. The most stable structures were confirmed by comparing vertical detachment energies (VDEs) with the experimental measurements. A dramatic drop of VDE at n = 3 has been observed in the experiment, which is in accordance with the structural change of (MgCl2)2(H2O)n-. Compared to the neutral clusters, the excess electron induces two significant phenomena in (MgCl2)2(H2O)n-. First, the planar D2h geometry can be converted into a C3v structure at n = 0, making the Mg-Cl bonds easier to be broken by water molecules. More importantly, a negative charge-transfer-to-solvent process occurs after adding three water molecules (i.e., at n = 3), which leads to an obvious deviation in the evolution of the clusters. Such electron transfer behavior was noticed at n = 1 in monomer MgCl2(H2O)n-, indicating that the dimerization between two MgCl2 molecules can make the cluster more capable of binding electron. In neutral (MgCl2)2(H2O)n, this dimerization provides more sites for the added water molecules, which can stabilize the entire cluster and maintain its initial structure. Specifically, filling the coordination number to be 6 for Mg atoms can be seen as a link between structural preferences in the dissolution of the monomers, dimers, and extended bulk-state of MgCl2. This work represents an important step forward into fully understanding the solvation of MgCl2 crystals and other multivalent salt oligomers.

All‐Solid‐State Chloride‐Ion Battery with Inorganic Solid Electrolyte

AbstractChloride‐ion batteries have some attractive properties such as high energy density and low cost. However, they have poor cycle performance because chloride as an active material tends to dissolve into a polar solvent. Herein, an all‐solid‐state chloride‐ion battery is demonstrated with KCl‐doped PbCl2 as a solid electrolyte to suppress the dissolution of chloride. The all‐solid‐state cell with BiCl3 as the cathode had an initial discharge capacity of 187 mAh g−1, which corresponds to 73 % of the theoretical capacity of BiCl3. Moreover, it exhibited better cyclability compared to the previously reported non‐aqueous cell with BiCl3 cathode. During the charge‐discharge process, XRD and XPS analysis confirmed the unique behavior of conversion reaction by Cl− anion, where Bi is produced by discharging and BiCl3 returns by charging.

Formation and growth mechanism for niobium oxide nanoparticles: atomistic insight from in situ X-ray total scattering.

Understanding the mechanisms for nanoparticle nucleation and growth is crucial for the development of tailormade nanomaterials. Here, we use X-ray total scattering and Pair Distribution Function analysis to follow the formation and growth of niobium oxide nanoparticles. We study the solvothermal synthesis from niobium chloride in benzyl alcohol, and through investigations of the influence of reaction temperature, a formation pathway can be suggested. Upon dissolution of niobium chloride in benzyl alcohol, octahedral [NbCl6−xOx] complexes form through exchange of chloride ligands. Heating of the solution results in polymerization, where larger clusters built from multiple edge-sharing [NbCl6−xOx] octahedra assemble. This leads to the formation of a nucleation cluster with the ReO3 type structure, which grows to form nanoparticles of the Wadsley–Roth type H-Nb2O5 structure, which in the bulk phase usually only forms at high temperature. Upon further growth, structural defects appear, and the presence of shear-planes in the structure appears highly dependent on nanoparticle size.

Dissolution of potassium chloride as a test process for isothermal calorimeters operated in the milli-Watt range

A test and calibration method for isothermal calorimeters equipped with a device for liquid injection and mixing is described. The procedure was developed with special reference to calorimeters operated with heat flow values in the milli-watt range. The investigated reaction was the dissolution of potassium chloride in water at 298 K in the concentration range 56–80 water molecules per KCl entity or molalities of 0.7−1 mol kg−1. The solution enthalpies (ΔsolH) were assessed after electrical calibration and correction for side effects obtained from separate blank measurements. The obtained values were corrected to the state of infinite dilution (ΔsolH∞) at each experimental molality by use of literature values of the relative apparent enthalpy of dilution. The obtained result was 229.6 ± 1.0 J g−1 (n = 16). The solution enthalpy (ΔsolH) as a function of molality in the experimental concentration interval was fitted by a 1-order polynomial resulting in a slope of -12.3 J g−1 mol−1 kg and intercept of 240.5 J g−1. The results are suggested as reference values for validation of calorimeters calibrated electrically or for the purpose of calibration.

Characteristics of Films on the Surface of Sea Sand and Effects on the Dissolution of Chloride

In this study, the effects of the specimen preparation method, temperature, and duration of the extraction step for the determination of the water-soluble chloride content of sea sand were investigated. The results demonstrated that increasing the heating temperature and duration promoted the dissolution of chloride, where the maximum value was obtained at 80°C and 60 min. Hot water extraction (80°C/60 min) could eliminate the effects of different specimen preparation methods on the final test results. Therefore, a new method was developed with drying at a temperature of 110 ± 5°C and hot water extraction at a temperature of 80°C for 60 min. The suitability of the new method for determining the water-soluble chloride content of sea sand was verified by testing the extracted specimens again. The results indicated that the chloride in sea sand dissolved fully with the new method, and thus it is suitable for testing the water-soluble chloride content of sea sand. Finally, the organic and inorganic compositions of the film adsorbed on the surface of sea sand were studied based on thermogravimetric analysis, inductively coupled plasma atomic emission spectrometry, ion chromatography, and total organic carbon measurements. The results indicated that a layer of substance (a multi-substance film) was adsorbed onto the surface of sea sand. This layer comprised inorganic salts (such as Cl–, Na+, Mg2+, SO42–, and Ca2+) and organic compounds, which were related to the composition of sea water. The multi-substance film greatly affected the dissolution and diffusion of chloride in the sea sand. Hot water extraction accelerated the dissolution of the film and increased the test results in terms of the water-soluble chloride contents.

Monolithic Nanoporous Zn Anode for Rechargeable Alkaline Batteries.

The fabrication of monolithic nanoporous zinc bears its significance in safe and inexpensive energy storage; it can provide the much needed electrical conductivity and specific area in a practical alkaline battery to extend the short cycle life of a zinc anode. Although this type of structure has been routinely fabricated by dealloying, that is, the selective dissolution of an alloy, it has not led to a rechargeable zinc anode largely because the need for more reactive metal as the dissolving component in dealloying limits the choices of alloy precursors. Here, we apply the mechanism of dealloying, percolation dissolution, to design a process of reduction-induced decomposition of a zinc compound (ZnCl2) for nanoporous zinc. Using naphthalenide solution, we confine the selective dissolution of chloride to the compound/electrolyte interface, triggering the spontaneous formation of a network of 70 nm wide percolating zinc ligaments that retain the shape of a 200 μm thick monolith. We further reveal that this structure, when electrochemically oxidized and reduced in an alkaline electrolyte, undergoes surface-diffusion-controlled coarsening toward a quasi-steady-state with a length scale of ∼500 nm. The coarsening dynamics preserves the continuous zinc phase, enabling its uniform reaction and 200 cycles of stable performance at 40% depth of discharge (328 mAh/g) in a Ni-Zn battery.

Mechanisms controlling groundwater chemistry and assessment of potential health risk: A case study from South India

Protection and management of groundwater resources depends on full understanding of the processes controlling the groundwater chemistry and associated health risks. In view of this, the rural part of Wanaparthy district, Telangana State, India was chosen for the present study and the groundwater samples collected from there were chemically analyzed. Quality of groundwater is of alkaline nature and mostly fresh water type. According to Trilinear Diagram, the change of groundwater quality from Ca2+- HCO3− type to Na+- Cl− type through mixed water type suggests the gradual influence of anthropogenic activities on the aquifer system. Gibbs Diagrams demonstrate that the chemistry of groundwater is mainly controlled by rock-water interactions and the rest by evaporation due to impact of anthropogenic sources. Bivariate Diagrams (Na+vsCl−, Ca2++Mg2+vsSO42−+ HCO3− and Ca2++Mg2+- SO42−- HCO3−vs Na+- Cl−) clearly specify that the processes of weathering and dissolution of minerals, and ion exchange are the dominant controlling factors of groundwater chemistry. Hierarchical R-type Cluster Analysis illustrates that Group I (Cl−- Na+ and HCO3−) is considered natural contribution, Group 2 (SO42−- Mg2+- Ca2+) is natural or anthropogenic source and Group 3 (NO3−- K2+ - F−) is anthropogenic influence. As per the estimation of sources of ions in the groundwater body by Unmix Model, the Source 1 (NO3−, Cl−, SO42− and Na+) is related to the anthropogenic activities; Source II (Ca2+, HCO3−, Na+, SO42−, Mg2+ and Cl−) to the weathering of silicate minerals, dissolution of chloride and sulfate minerals; and Source III (K+, F−, Ca2+, HCO3− and Mg2+) to the weathering of fluoride, calcium, magnesium and potassium bearing minerals or the application of chemical compounds of potassium and fluoride ions. These sources lead to groundwater contamination in some locations, thereby causing unfit for drinking purpose. Health Risk Assessment with respect to NO3− and F− ions suggests that the Total Hazard Index of non-carcinogenic risk (> 1.0) is observed from 26.67%, 26.67% and 43.33% of the total groundwater samples and the threat is to children compared to men and women due to their smaller body weights. Therefore, the health risk reduction measures are recommended to improve the groundwater quality in the study region.

Experimental study on mechanical properties and durability of basalt fiber reinforced coral aggregate concrete

With the development of marine technology, the potential of coral aggregate concrete (CAC) for use in the construction of reefs has been identified. However, the shape, surface structure, high porosity, and chloride-ion-carrying properties of coral aggregates yield special microstructures and affect the mechanical properties and durability of CAC. This study investigates the effect of basalt fiber (BF) on the mechanical properties, chloride content carried in coral aggregates, and water absorption of CAC. The results indicate that with the increase in fiber content, the mechanical properties and water absorption resistance of basalt fiber reinforced coral aggregate concrete present an increasing trend then followed decreasing trend. Furthermore, 0.05% BF yields the highest improving effect on the mechanical properties and water absorption resistance at 28 days. Compared with the reference concrete, the compressive strength and splitting tensile strength of CAC with 0.05% BF increase by 9.87% and 1.36% at 28 days, respectively. When the fiber content continues to increase, the strengthening effect decreases, and cause adverse effects. The dissolution of chloride in coral aggregates was accelerated by 0.05% BF, while the chloride dissolution was inhibited by 0.1%–0.2% BF. Moreover, the microstructure of CAC is investigated to elucidate the enhancement mechanism of BF in terms of thermogravimetric analysis, theoretical total pore volume, fiber bonding performance, and fiber-matrix interfacial characteristics.

Factors controlling groundwater chemistry of Renigunta area, Chittoor District, Andhra Pradesh, South India: A multivariate statistical approach

Groundwater is a major source of water supply for domestic, agricultural and industrial purposes, particularly in semi-arid regions. Managing this resource in terms of quality and quantity is a crucial issue in order to fulfil the increasing need for water. In this study, Groundwater from 31 sampling sites of Renigunta area were collected during the pre-monsoon season of 2018. The order of major ions in the groundwater was as follows: Na+ > Ca2+ > Mg2+ > K+ and HCO3– > SO42− > Cl−. The data reduction techniques, for instance, factor analysis grouped the sampling sites into three distinct groups which are attributed to the overall influence of major ions, silicate weathering, and sulphate reduction processes. The cluster analysis in Q-mode grouped the sampling sites into fresh, hard and very hard categories whereas the cluster analysis in R-mode gave three distinct groups which are attributed to the overall impact of rock-water interaction, silicate weathering and dissolution of sulphate and chloride. Geochemical modelling reveals that the saturation index (SI) values of all wells were undersaturated concerning chloride and sulphate. In addition, the Gibbs plot reveals that water-rock interaction was the key process that governs groundwater chemistry in the study area, whereas the CAI-I and CAI-II indicate that the ion exchange process in between (Na+ + K+) and (Ca2+ + Mg2+). Even though, most wells are within acceptable limits, few cross them and some are quite close to acceptable limits indicating that water quality may deteriorate in the near future. Proper water quality monitoring is needed for groundwater sustainability in the study area.

Catalytic conversion of herbal residue carbohydrates to furanic derivatives in a deep eutectic solvent accompanied by dissolution and recrystallisation of choline chloride

Catalytic conversion of lignocellulosic biomass into furfural (FF) and 5-hydroxymethylfurfural (5-HMF) requires a high reaction temperature (150–230 °C) in aqueous/organic systems. In this study, a novel choline chloride–formic acid-SnCl4·5H2O (ChCl–Fa–SnCl4) catalytic system was designed to transform herbal residues (HRs) carbohydrates into furanic derivatives at temperatures below 140 °C. The total yield of FF and xylose from HR of Heteropogon contortus (L.) Beauv (HRH) was 67.5% at 140 °C for 10 min, while the total yield of 5-HMF and glucose from HR of Anemarrhena asphodeloides Bunge was 93.8% at 120 °C. Characteristics of substrates such as molecular weight had a great influence on formation of furanic derivatives and sugar release. Surprisingly, the dissolution and recrystallisation characteristics of ChCl make this catalytic system sustainable and economically attractive. Recovery of ChCl and SnCl4 was 73.3% following simple natural recrystallisation, and recovered material retained a high chemical reactivity for FF and 5-HMF production. Moreover, 100% lignin dissolution was achieved in this system at 140 °C, and ~ 77% could be precipitated and recovered by adding water.

Assessment of Physicochemical and Heavy Metal Properties of Groundwater in Edéa (Cameroon)

In order to assess the physicochemical and heavy metal properties of groundwater consumed in Edéa (Cameroon), 8 boreholes were randomly chosen from 8 sites and their suitability was evaluated using three norms viz Cameroonian Norm (NC207:2003-02) and International standards including (CODEX: 108-1981 and European Union, EU:1998). Water samples were collected in triplicates bimonthly and analyzed using standard methods. Physicochemical analysis showed high temperatures with a mean value of (30.26 ±2.4) °C, acidic pH 5.94±0.34 and very weak mineralization leading to an electrical conductivity value of (134, 96 ± 49.59) µS/cm. The relative abundance of major ions was Ca2+>Mg2+>Na+> NH4+>K+ for cations and NO-3> HCO-3-> PO43-> SO42->Cl- for anions. All these ions fell within acceptable limits recommended by NC207:2003-0 boreholes 2, CODEX: 108-1981 and EU: 1998 with an exception for nitrates, ammonium and phosphate contents which were above acceptable limits. Among heavy metals analyzed, results showed that only lead and manganese values were above the standards’; all boreholes were contaminated by Lead while only 32.5% was contaminated by Manganese. The main water types were Mg-Ca-SO43--Cl- and Mg-Ca-HCO3- can’t result to an alteration of the aquifer matrix (dissolution of Gypsum chloride) and influence of anthropogenic activities through infiltration of agricultural, industrial and domestic waste water. These results showed that water of Edéa is not suitable for human consumption and must be appropriately treated before any usage.

Investigation of Dissolution of Cuprous Chloride in Aqueous Hydrochloric Acid Solution with Application to Hydrogen Production Technologies

Fossil-fuel-based methods of production, transformation and use of energy are causing environmental concerns such as ozone depletion, acid rain and climate change while depleting the earth of its resources. Sustainable alternatives for energy transformation are being sought and a hydrogen economy is a potential avenue. The thermochemical copper-chlorine (Cu-Cl) cycle for water splitting into its constituents is a promising option to produce high quantities of hydrogen. One of the steps involved in the process of hydrogen production from water using the thermochemical Cu-Cl cycle is the dissolution of cuprous chloride particles in hydrochloric acid. The purpose of this study is to propose an experimental design to examine the dissolution of cuprous chloride in an aqueous hydrochloric acid solution in order to observe the reaction time and kinetics. This data will be used to develop an empirical model that correlates quantity of cuprous chloride, concentration of hydrochloric acid, electrical conductivity, and dissolution time using analysis of variance (ANOVA). Extrapolating the data gathered from the empirical model to an industrial scale will enable dissolution time prediction based on concentration and temperature for complex multiphase reactions.

Analysis of operating variables for Yerba mate leaves supercritical carbon dioxide extraction

Given the increasing demand for potassium in Brazil, the mining and use of carnallite is becoming increasingly important, because the current source of potassium, sylvinite, is being depleted and there is a risk of shortages. Based on theoretical and practical data available in existing literature, this work describes the development, simulation, and economic feasibility of a process for dissolution and crystallization of potassium chloride from carnallite ore. Positive results were obtained following the application of the Hoffman diagram and determination of the corresponding equation. The proposed process provided over 85% potassium chloride crystallization, demonstrating its superior performance, compared to existing procedures.

Dissolution of Trihexyltetradecylphosphonium Chloride in Supercritical CO2

We present steady-state and time-resolved fluorescence spectroscopic data derived from coumarin 153 (C153) in a binary solution comprised of trihexyltetradecylphosphonium chloride ([P6,6,6,14]+Cl−) and supercritical CO2 (scCO2). Steady-state fluorescence of C153 was measured in neat scCO2 and ionic liquid (IL)-modified scCO2 solutions. The steady-state excitation and emission peak frequency data in neat scCO2 and IL/scCO2 diverge at low fluid density (ρr = ρ/ρc < 1). The prominent spectral differences at low fluid density provided clear evidence that C153 reports different microenvironments, and suggested that the IL is solubilized in the bulk scCO2 and heterogeneity of the C153 microenvironment is readily controlled by scCO2 density. C153 dimers have been reported in the literature, and this formed the basis of the hypothesis that dimerization is occurring in scCO2. Time-dependent density functional theory (TD-DFT) electronic structure calculations yielded transition energies that were consistent with excitation spectra and provided supporting evidence for the dimer hypothesis. Time-resolved fluorescence measurements yielded triple exponential decays with time constants that further supported dimer formation. The associated fractional contributions showed that the dominant contribution to the intensity decay was from C153 monomers, and that in high density scCO2 there was minimal contribution from C153 dimers.

Corrosion behavior and pitting susceptibility of in-situ Ti-based metallic glass matrix composites in 3.5 wt.% NaCl solutions

The Ti62Zr12V13Cu4Be9, Ti58Zr16V10Cu4Be12, Ti46Zr20V12Cu5Be17, and Ti40Zr24V12Cu5Be19 metallic glass matrix composites (MGMCs) were prepared by copper mould casting. The corrosion resistance and the pitting susceptibility of Ti-based MGMCs were tested on their cross-sectional areas in 3.5wt.% NaCl solutions by potentiodynamic polarization measurements. The composites with lower Ti contents (Ti40Zr24V12Cu5Be19 and Ti46Zr20V12Cu5Be17) exhibit a low resistance to the chloride induced pitting and local corrosion. The preferential dissolution of amorphous matrix is explained by the high chemical reactivity of beryllium element compared to that of stable dendrites and by the detected lower Ti and V contents. However, fairly good passivity was found in the composite with higher Ti contents (Ti62Zr12V13Cu4Be9). XPS measurements revealed that protective Ti-enriched oxide film was formed on the composite surface, additionally, lower content of beryllium element in amorphous matrix hinder the selective corrosion of amorphous matrix. The assessment of experimental observation leads to a proposed corrosion mechanism involving selective dissolution of amorphous matrix and chloride induced pitting process.

Alkaline pretreatment for chlorine removal from high-chlorine rhodochrosite

Chloride in manganese ore adversely affects mineral extraction. The mechanisms and the factors that influence an alkali pretreatment to removal chlorine from manganese ore were explored to eliminate hazards posed by chlorine during the electrolysis of manganese. The results showed that sodium carbonate, when used as an alkaline additive, promoted the dissolution of insoluble chloride, enhanced the migration of chloride ions, and effectively stabilized Mn2+. The optimal conditions were a sodium carbonate concentration of 0.45 mol·L−1, a liquid-solid ratio of 5:1 mL·g−1, a reaction time of 1 h, and a temperature of 25°C. The chlorine removal efficiency was greater than 95%, and the ore grade (Mn) was increased by 2.7%.

Statistical Analysis of High Fluoride Groundwater Hydrochemistry in Southern India: Quality Assessment and Implications for Source of Fluoride

The present investigation studied fluorosis among the population in the Jaggayyapalem area of Southern India resulting from the occurrence of fluoride in groundwater. Thirty water samples were collected and analyzed for major cations: Na+, Ca2+, K+, Mg2+, and anions: Cl−, CO32−, HCO3−, SO42−, and F−. Analyzed data were utilized to characterize the hydrochemical process dominant in this area. Gibb's diagrams suggested that the water rock interaction was the major driving force controlling water chemistry. Possible sources of fluoride were chemical weathering and leaching of fluorine-bearing minerals present in hard rocks and alluvial formations under the alkaline environment in arid to semiarid conditions. Multivariate analysis in terms of principle component analysis and cluster analysis furnished information about the sources of various parameters in groundwater samples. The correlation study revealed that Ca-K-HCO3-CO3, Mg-HCO3, and K-CO3-Cl are significantly correlated. Furthermore, from this study, it is clear that the source of F was related to Na-Mg silicate minerals and also due to dissolution of carbonate and chloride.

Au/BiOCl heterojunction within mesoporous silica shell as stable plasmonic photocatalyst for efficient organic pollutants decomposition under visible light

A new mesoporous silica protected plasmonic photocatalyst, Au/BiOCl@mSiO2, was prepared by a modified AcHE method and a subsequent UV light induced photodeposition process. The surfactant-free heterojunction allows the electrons spontaneously flow from Au to nearby BiOCl surface, leading to the accumulation of positive charges on Au surface, and negative charges on Bi species under visible light. Au/BiOCl@mSiO2 exhibits high visible light photocatalytic efficiency in complete oxidation of aqueous formaldehyde and Rhodamin B. We showed that a positive relationship exists between the LSPR effect and rate enhancements, and leads to a hypothesis that the metallic Au LSPR enhances the photocatalytic rates on nearby semiconductors by transferring energetic electrons to BiOCl and increasing the steady-state concentration of active OH species by a multi-electron reduction of molecular oxygen. The OH species is the main oxidant in photocatalytic transformations, whose intensity is greatly enhanced in the dye-involving systems due to the synergetic effect between LSPR and dye sensitization processes. In addition, the mesoporous SiO2 shell not only inhibits the over growth of BiOCl nanocrystals within the silica frameworks, but also protects the dissolution of chloride or Au species into aqueous solution, which ultimately makes the Au/BiOCl@mSiO2 catalysts rather stable during photocatalysis.