Aqueous Chloride Media Research Articles

Effect of surface corrosion on the zeta potential of copper in acidic solutions

The comprehensive investigation was conducted to analyze the corrosion behavior and surface potential of pure copper surfaces in various acidic solutions. We carried out Zeta potential measurement, electrochemical measurement and in situ Raman spectroscopy to investigate the corrosion process and surface potential of copper in acidic solutions with different pH. It was found that the variation in zeta potential with pH corresponds to the corrosion behavior of copper during this process. In 1mmol / L aqueous chloride media, when the pH is greater than 3.5, unalloyed copper is oxidized to monovalent copper. At this stage, as the pH decreases, the zeta potential gradually increases. When the pH reaches 3.5, the Zeta potential reaches the highest, and the rate of cuprous oxide formation reaches the maximum. When the pH continues decrease, unalloyed copper begins to be oxidized to divalent copper, and the zeta potential will also decrease, the surface charge state shifts to the positive direction. Furthermore, our experimental findings are complemented by Density Functional Theory (DFT) calculations.

Improved Test Methods and Models for Localized Corrosion Assessment of Stainless Steels in Aqueous Chloride Media with Low Dissolved Oxygen

Experimental foundation has been established for improving corrosion models for stainless steels exposed to neutral aqueous chloride media with low levels of dissolved oxygen (DO). Accurate repassivation potentials were measured for UNS S31603 and UNS S32205 alloys in chloride electrolytes at room and elevated temperatures using Tsujikawa-Hisamatsu electrochemical (THE) and cyclic potentiodynamic polarization (CPP) methods. It was observed that the repassivation potential values measured using the CPP method were lower than the ones obtained from THE method for the same environmental conditions. Cyclic polarization scans in aqueous chloride media were conducted at different reverse scan rates resulting in varied repassivation potentials. Medium-term corrosion potentials were measured in chloride media with controlled dissolved oxygen levels ranging from 20 ppb to 400 ppb. These results were used as inputs for improving model prediction for repassivation and corrosion potentials. In an extension of previous modeling studies, an improved mechanistic repassivation model was developed based on a new generalized theory that explicitly accounts for the adsorption of water rather than treating it as an ever-present background. With a flexible definition of the repassivation current density, the new repassivation model reproduces the experimental repassivation potentials obtained using THE and CPP methods. The dependence of corrosion potential on DO has been modeled using a mixed-potential model. It has been demonstrated that the effect of agitation (caused by the bubbling of oxygen) needs to be accounted for to describe the corrosion potential, especially at low DO, where mass transport is important. The combined model correctly predicts the occurrence of localized corrosion when tested against exposure data from the literature.

A novel biomimetic probe for galectin‐3 recognition: Chemical synthesis and structural characterization of a β‐galactose branched sodium hyaluronate

AbstractSodium hyaluronate (HA), a derivative of hyaluronan, is a natural and biocompatible polysaccharide that interacts with cluster of differentiation‐44 receptor to promote fine‐tuning of inflammation, fibrosis, and tissue remodeling. HA has a smaller molecular weight than hyaluronan and is overall more stable being less prone to oxidation. In this study, we report a novel lactose‐functionalized sodium hyaluronate, named HYLACH®. Functionalization with multiple β‐galactose residues facilitates its interaction with galectin‐3, a β‐galactose binding lectin implicated in various pathological processes including inflammation, host defense, and fibrosis, especially critical in idiopathic pulmonary fibrosis (IPF). Our strategy was to modify HA, to varying extents, at carboxyl sites with 1‐amino‐1‐deoxy‐lactitol, in the presence of 4‐(4,6‐dimethoxy‐1,3,5‐triazin‐2‐yl)‐4‐methyl morpholinium chloride in aqueous media. We characterized the chemical structure, molecular weight, and degree of substitution of HYLACH® using NMR spectroscopy and size exclusion chromatography. We further determined several key parameters including its stability toward enzymatic degradation and the binding affinity and conformational changes of galectin‐3 interaction with HYLACH®. Collectively, the generation of a novel functionalized HA with an ability to bind and suppress galectin‐3 function, in combination with safety and biocompatibility, offers the opportunity to test this compound in therapeutic trials of devastating fibrotic diseases such as IPF.

Mitigation of Galvanic Corrosion in CFRP-Metal Couples through Addressing the Carbon Surface

Carbon-based reinforcements are widely used in composite materials for a wide range of applications including wind energy and transportation. In the later, the carbon-fiber reinforced polymers (CFRP) components are often joined together with metallic parts creating conditions for galvanic corrosion. Therefore, a deeper understanding of the electrochemical processes occurring at the carbon surfaces is crucial for developing new approaches for the corrosion protection of multi-material assemblies.In the present work, the electrochemical performance of different types of carbons, namely HOPG (Highly Ordered Pyrolytic Graphite) glassy carbon (GC), and CFRP, have been investigated in neutral NaCl solutions under cathodic polarization. At the potentials relevant to galvanic coupling to metals the CFRP surface is the most electrochemically active of the studied carbon surfaces. The ranking of the studied surfaces in terms of supporting the oxygen reduction reaction was established as follows: CFRP > GC > HOPG. It was found that the observed differences in the electrochemical responses of these materials to ORR are correlated with the proportions of edge sites present on each carbon surface [1].Under galvanic coupling conditions in multi-material structures composed of CFRP and Al alloys or Zn, significant degradation of the composite surface occurs at the carbon/electrolyte interface and due to an attack on the epoxy of the matrix phase most probably resulting from nucleophilic attack by hydroxyl and perhydroxyl ions, formed as a result of the oxygen reduction reaction on carbon fiber. The obtained results demonstrate the intense electrochemical activity of CFRP even when slightly polarized cathodically with a concomitant sharp increase in the pH above its surface. Contrary to expectations, exposure of CFRP to degradative high pH media before galvanic coupling did not provoke accelerated galvanic corrosion of the coupled metal under bulk electrolyte immersion conditions [2].The use of the corrosion inhibition approach to suppress the degradation of CFRP and reduce its cathodic activity in the galvanic couples was also demonstrated. It was found that the presence of sodium dodecyl sulphate (SDS) in the electrolyte offers a clear inhibition effect. From the results, it is concluded that SDS interacts with CFRP surface resulting in the formation of a persistent adsorbed layer. Surface analysis by scanning electron microscopy confirms mitigation of the CFRP composite degradation under impressed cathodic polarization in the presence of SDS or after prior exposure to SDS-containing solution [3].[1] S.U. Ofoegbu, M.G.S. Ferreira, H.I.S.Nogueira, M.L. Zheludkevich, Comparison of the Electrochemical Response of Carbon-Fiber-Reinforced Plastic (CFRP), Glassy Carbon, and Highly Ordered Pyrolytic Graphite (HOPG) in Near-Neutral Aqueous Chloride Media, C, 9 (2023) 7.[2] S.U. Ofoegbu, M.C. Quevedo, A.C. Bastos, M.G.S. Ferreira, M.L. Zheludkevich, Electrochemical characterization and degradation of carbon fibre reinforced polymer in quiescent near neutral chloride media, npj Materials Degradation, 6 (2022) 49.[3] S.U. Ofoegbu, K. Yasakau, S. Kallip, H.I.S.Nogueira, M.G.S. Ferreira, M.L. Zheludkevich, Modification of carbon fibre reinforced polymer (CFRP) surface with sodium dodecyl sulphate for mitigation of cathodic activity, Applied Surface Science, 478 (2019) 924-936.

Green preparation of new pyrimidine triazole derivatives via one-pot multicomponent reactions of guanidine.

In this research the goal was to produce novel pyrimidine triazole compounds in high yields using triethylamin as an efficient catalyst. These new compounds were synthesized by using multicomponent reaction of aldehydes, guanidine, electron deficient acetylenic compounds, tert-butyl isocyanide and hydrazonoyle chloride in aqueous media. Due to the presence of an NH group, which was assessed using two different methodologies, newly synthesized pyrimidine triazoles have antioxidant properties. Additionally, the antibacterial activity of newly created pyrimidine triazoles was assessed using the disk distribution method with two different types of Gram-positive bacteria and Gram-negative bacteria, demonstrating that the use of these compounds prevented the growth of bacteria. Applied to the preparation of pyrimidine triazole derivatives, this method has short reaction times, high product yields, and the ability to separate catalyst and product using simple procedures.

Comparison of the Electrochemical Response of Carbon-Fiber-Reinforced Plastic (CFRP), Glassy Carbon, and Highly Ordered Pyrolytic Graphite (HOPG) in Near-Neutral Aqueous Chloride Media

Carbon-fiber-reinforced polymers (CFRP), being conductive, are capable of supporting cathodic oxygen reduction reactions (ORR) and thus promote galvanic corrosion when coupled to many metallic materials. Hence, understanding cathodic processes at carbon surfaces is critical to developing new strategies for the corrosion protection of multi-material assemblies. In the present work, the electrochemical responses of CFRP, glassy carbon, and HOPG (Highly Ordered Pyrolytic Graphite) have been evaluated in a quiescent 50 mM NaCl solution, and their respective activities towards ORR have been ranked. Employing the averages of the specific charges (CFRP, 129.52 mC cm−2; glassy carbon, 89.95 mC cm−2; HOPG, 60.77 mC cm−2) passed during 1 h polarization of each of the 3 carbon surfaces at −1000 mVSCE in the test media as a ranking criterion, the propensities of the 3 carbon surfaces (CFRP, GC, and HOPG) to support cathodic activities that can lead to anodic metal dissolution on galvanic coupling to metallic materials are ranked thusly; CFRP > GC > HOPG. This ranking is consistent with the trend of capacitance values obtained in this work: CFRP (19.5 to 34.5 μF cm−2), glassy carbon (13.6 to 85.5 μF cm−2), and HOPG (1.4 to 1.8 μF cm−2). A comparison of electrochemical data at potentials relevant to galvanic coupling to metals indicated that at these cathodic potential(s) the CFRP surface is the most electrochemically active of the studied carbon surfaces. On the basis of the values and trends of the electrochemical parameters evaluated, it is postulated that the observed differences in the electrochemical responses of these 3 carbon-rich surfaces to ORR are significantly due to differences in the proportions of edge sites present on each carbon surface. These results could provide valuable insights on plausible strategies for designing carbon surfaces and carbon fiber composites with reduced activity toward ORR for corrosion protection applications or enhanced activity towards ORR for energy applications.

Green Synthesis and Antioxidant Activity Investigation of New Thiazinotriazines: Reduction of Organic Pollutant Using Fe3O4/TiO2/CuO@MWCNTs MNCs

The Petasites hybridus rhizome water extract was used as a green media for the preparation of the Fe3O4/TiO2/CuO@MWCNTs magnetic nanocomposites (Fe3O4/TiO2/CuO@Multi-Walled Carbon Nanotubes) and its activity was evaluated by using it in the one-pot multicomponent reaction of isatoic anhydrides, electron deficient acetylenic compounds, α-haloketones, ammonium acetate, isothiocyanates and hydrazoyl chloride in aqueous media at room temperature for the production of novel derivatives of thiazinotriazines in excellent yields. Moreover, reduction of organic pollutants such 4-nitrophenol (4-NP) was performed by synthesized Fe3O4/TiO2/CuO@MWCNTs magnetic nanocomposites in water at room temperature. The outcomes showed this catalyst decreased organic pollutants in few seconds. The synthesized thiazinotriazines have OH and NH functional groups that have acidic hydrogen and show high antioxidant activity. The employed process for the production of thiazinotriazines has some benefits such as short time of reactions, excellent efficiency of product, easy separation of catalyst and products. HIGHLIGHTS In medicinal chemistry, the heterocyclic compounds have a well-known subject due to having wide area of biological activities of these compounds. Therefore these compounds are very important and for the synthesis of these compounds existed many procedures. Multicomponent reactions (MCRs) is one of the process for the preparation of biological activities heterocyclic compounds with many benefits such as having atom economic, an useful and excellent efficiency in the generation of heterocyclic compounds relative to many stage reactions for preparation of organic compounds The present procedure avoids the use of toxic solvent. Benzazepines, which have a seven-membered aza-heterocyclic fused aromatic ring, are of interest because of their biological activity and use as building blocks for natural product synthesis and drug discovery.

Hydration of divalent lanthanides, Sm2+ and Eu2+ : A molecular dynamics study with polarizable AMOEBA force field.

The chemistry of divalent lanthanides, Ln2+ , is a growing sub-field of heavy element chemistry owing to new synthetic approaches. However, some theoretical aspects of these unusual cations are currently underdeveloped, especially as they relate to their dynamic properties in solution. In this work, we address the hydration of two of the classical Ln2+ cations, Sm2+ and Eu2+ , using atomic multipole optimized energetic for biomolecular applications (AMOEBA) force fields. These cations have not been parameterized to date with AMOEBA, and few studies are available because of their instability with respect to oxidation in aqueous media. Coordination numbers (CN's) of 8.2 and 8.1 respectively for Sm2+ and Eu2+ , and 8.8 for both Sm3+ and Eu3+ have been obtained and are in good agreement with the few available AIMD and X-ray absorption fine structures studies. The decreased CN of Ln2+ compared with Ln3+ arises from progressive water exchange events that indicates the gradual stabilization of 8-coordinate structures with respect to 9-coordinate geometries. Moreover, the effects of the chloride counter anions on the coordination of Ln2+ cations have been studied at different chloride concentrations in this work. Lastly, water exchange times of Ln2+ cations have been calculated to provide a comprehensive understanding of the behavior of Eu2+ and Sm2+ in aqueous chloride media.

Green Synthesis and Biological Activity Investigation of New Thiazinotriazines: A Combined Experimental and Theoretical Investigation

The Petasites hybridus rhizome water extract was used as a green media for the preparation of the Fe3O4/TiO2/CuO@MWCNTs magnetic nanocomposites and its activity was evaluated by using it in the one-pot multicomponent reaction of isatoic anhydrides, electron deficient acetylenic compounds, α-haloketones, ammonium acetate, isothiocyanates and hydrazonoyl chloride in aqueous media at room temperature for the production of novel derivatives of thiazinotriazines in excellent yields. The synthesized thiazinotriazines have OH and NH functional groups that have acidic hydrogen and show high antioxidant activity. Moreover, reduction of organic pollutants such 4-nitrophenol (4-NP) was performed by synthesized Fe3O4/TiO2/CuO@MWCNTs in water at room temperature. The outcomes showed this nanocatalyst was decreased organic pollutants in few seconds. Also, to better understanding reaction mechanism density functional theory based quantum chemical methods have been applied. The employed process for production of thiazinotriazines has some benefits such as short time of reactions, excellent efficiency of product, easy separation of catalyst and products.

Assessment of extraction kinetics of separation of Sm (III) and Co (II) in the presence of lactic acid using DEHPA as an organic carrier

ABSTRACT This work reports the kinetics and the mechanism of extraction and separation of Sm (III) and Co (II) from an aqueous chloride medium with lactic acid as a complexing agent using DEHPA in petrofin. The influence of stirring speed and temperature was investigated to learn about the extraction regime. The increase in stirring speed and interfacial area led to a rise in the extraction rate of Sm (III) and Co (II). The extraction rate is negligibly dependent on pH, which can be ascribed to the buffering nature of lactic acid present in the aqueous feed. The results clarified that the extraction regime is governed by diffusion with rate indicative reaction at the interface. The extraction mechanism involved in the process has been derived based on kinetic data. Low, stirring speed and low interfacial area are necessary for efficient separation of Sm (III) and Co (III), as evident from the kinetic studies.

Influence of some added electrolytes on the surface and thermodynamic propertiesof cetylpyridinium chloride in aqueous medium

The effect of some added electrolytes, viz. NaCl, CaCl2 and AlCl3, on the critical micelle concentration (CMC),maximum surface excess concentration (Γmax) and minimum area per molecule (Amin) at air-liquid interface of a cationicsurfactant cetylpyridinium chloride (CPC) in aqueous solutions have been studied at 288.15, 293.15 and 298.15 K usingtensiometric method. The effect of an added electrolyte on decreasing CMC of CPC is found to be in the order (AlCl3) >(CaCl2) > (NaCl), which falls in the same order as of the moles chloride ions furnished by each mole of the addedelectrolyte. The Γmax decreases with increasing temperature and electrolyte concentration leading to an enhanced availablearea per molecule at the air-liquid interface. The process of micellization and adsorption of CPC at air-liquid interface areboth favoured by exothermic enthalpy change as well as entropy gain. The observed features such as lowering of CMC,higher thermodynamic micellar stability, more relaxed surfactant molecules at the interface, due to an added electrolyte,may be exploited for improving the efficiency of the surfactant as a detergent, solubilizing agent, froth floatation process forconcentrating ores, petroleum oil recovery and oil spill management.

Utilization of octenyl succinic anhydride-modified pea and corn starches for stabilizing oil-in-water emulsions

In this study, pea starch (41.5% amylose), normal corn starch (32.9% amylose), and waxy corn starch (1.7% amylose) were modified using three concentrations of octenyl succinic anhydride (OSA). The degrees of substitution, thermal properties, and pasting properties of the derived OS-starches were determined. Canola oil-in-water (O/W) emulsions were prepared using a high-pressure homogenizer with the OS-starches to evaluate their emulsifying properties, with gum Arabic (GA) being included as the industry standard for comparison. Droplet-size distributions, zeta potentials, accelerated stability, and storage stability of the resultant emulsions were determined and compared. Emulsion stability under various environmental conditions was also investigated, including pH 2–7, 0–1.0 M sodium chloride in aqueous medium, and incubation at 90 °C for 30 min. Overall, the ability of the emulsifiers in stabilizing O/W emulsions followed an ascending order of OS-PS < GA ≤ OS-NCS < OS-WCS. Emulsifying properties of the OS-starches and stability of the resultant emulsions were generally enhanced with a higher degree of substitution. The interrelationships among the molecular structures (e.g., amylose content and degree of substitution), functional properties (e.g., retrogradation rate), and emulsifying ability of the OS-starches were also elucidated. The new findings from the study can be used to further tailor the structures of OS-PS to improve the emulsifying properties for potential industrial uses.

Solvent Extraction of Scandium and Yttrium Using Carboxylic Acid

Separation of scandium (Sc) from yttrium (Y) in aqueous chloride media by solvent extraction using Versatic acid 10 was investigated. Conventional slope analysis method revealed the extraction equilibrium formulation of the metals. Sc is more strongly extracted than Y by Versatic acid 10, and the separation factor of the metals is quite high at 1.93 × 104. Complete stripping of Sc from the loaded organic solution of Versatic acid 10 was achieved by 3M HCl solution. Then Versatic acid 10 was applied to solvent impregnated resin (SIR), separation of Sc was progressed via Langmuir adsorption model.

Advanced oxidation of benzalkonium chloride in aqueous media under ozone and ozone/UV systems – Degradation kinetics and toxicity evaluation

This study investigates the degradation efficiency and kinetics of benzyldimethyldodecylammonium chloride (DDBAC) via O3/UV and O3 treatment. A catalytic effect of UV on ∙OH formation was found for the O3/UV treatment. A 91% DDBAC degradation efficiency was achieved within 20 min at an O3 dosage of 0.37 g∙h−1 and pH of 8.0, whereas only 19% DDBAC was degraded for the O3 treatment. A high pH, high O3 dosage and low initial DDBAC concentration are prompting DDBAC degradation for O3/UV and O3 treatment. However, unlike O3 treatment, O3/UV shows a great performance without requiring a high pH and high O3 dosage. Pseudo-first-order reaction kinetics were applicable for all process conditions. The scavenging experiments with tert-butanol confirmed a contribution of ∙OH radicals to DDBAC oxidation for the O3 treatment, while the combined effects of ∙OH radicals and UV photolysis were responsible for the O3/UV treatment. Furthermore, the complex matrix from real wastewater inhibited the oxidation process due to the competition for oxidative species between organic matter and DDBAC. Two Factor Interaction and quadratic statistical models were developed by a central composite design and proven to be precise and reliable to predict the DDBAC degradation process for the O3 and O3/UV treatment. The detoxification tests based on respirometric principles confirmed that the O3/UV system was quite efficient to reduce the toxicity of the aqueous media containing DDBAC, compared to other treatment techniques explored. Compared to the O3 treatment alone, the present study provides a more efficient approach for DDBAC degradation under mild conditions via the O3/UV treatment.

Photo-Chlorine Production with Hydrothermally Grown and Vacuum-Annealed Nanocrystalline Rutile

Photo-generated high-energy surface states can help to produce chlorine in aqueous environments. Here, aligned rutile (TiO2) nanocrystal arrays are grown onto fluorine-doped tin oxide (FTO) substrates and activated either by hydrothermal Sr/Ba surface doping and/or by vacuum-annealing. With vacuum-annealing, highly photoactive films are obtained with photocurrents of typically 8 mA cm−2 at 1.0 V vs. SCE in 1 M KCl (LED illumination with λ = 385 nm and approx. 100 mW cm−2). Photoelectrochemical chlorine production is demonstrated at proof-of-concept scale in 4 M NaCl and suggested to be linked mainly to the production of Ti(III) surface species by vacuum-annealing, as detected by post-catalysis XPS, rather than to Sr/Ba doping at the rutile surface. The vacuum-annealing treatment is proposed to beneficially affect (i) bulk semiconductor TiO2 nanocrystal properties and electron harvesting, (ii) surface TiO2 reactivity towards chloride adsorption and oxidation, and (iii) FTO substrate performance.Graphical abstractPhoto-chlorine production is possible in aqueous chloride media under neutral conditions with rutile nanocrystal arrays under illumination from band gap–matched LEDs.

Controlling the structural and optical properties of tungsten oxide films synthesized under environmentally friendly conditions

Semiconductor oxides applied for light harvesting present special optical characteristics, such as high refractive index, high absorption coefficient, and low photoemission yield. This work reports an optimized, new, and easy route to obtain tungsten oxide films by anodization of tungsten foils, with controlled optical properties by using sodium chloride as an active electrolyte. Different from anodization processes, which are carried out in strong acidic media and/or with considerable concentrations of neutral electrolytes, we used small concentrations of sodium chloride in aqueous media to ensure the environmentally friendly conditions. A factorial design 23 showed the effects of electrolyte concentration, applied voltage, and thermal annealing (300 °C, 60 min) on the structural and optical properties of the films. The structure of films was characterized by atomic force microscopy, Raman spectroscopy, X-ray diffraction and photoluminescence (PL) spectroscopy. Real and imaginary refractive indexes, as well as the absorption curves, were obtained by ellipsometry. Two competitive reactions occurred on the anode surface: oxidation of tungsten and chlorine evolution. Continuous growth and dissolution of the oxide layer contribute to the production of porous films. The applied voltage directly affects thickness and structure of films, which originate different crystal structures, after thermal annealing. Thermal annealing is the main factor that modifies particle size and texture of the oxide layers. The PL bands allowed characterizing the main transitions, between 300 and 630 nm, when excited at 266 nm. Crystal growth contributed to the annihilation of luminescent centers during the annealing process.

Physico-chemical study of the interaction between levofloxacin hemihydrate Drug with Cetylpyridinium chloride in aqueous medium: conductometric and spectrophotometric investigation

Herein, the interaction between levofloxacin hemihydrate (LFH), a fluoroquinolone antibiotic drug, and cetylpyridinium chloride (CPC), a cationic surfactant, has been studied by applying conductometric and spectrophotometric techniques at various temperatures. The binding constant of LFH to various types of micelles has also been calculated by means of the Benesi-Hildebrand Equation. (CPC+LFH) mixed system exhibits lower critical micelle concentration (cmc) values in magnitude compared to the pure CPC in aqueous solution at a particular temperature as confirmed by the conductometric measurements. The profound change in the cmc values of the (CPC+LFH) mixtures by varying the concentration of LFH signify the synergistic (attractive) interaction between CPC and LFH. In addition, The negative values of standard free energy demonstrate the stability of the (CPC+LFH) mixture. Furthermore, the other thermodynamic parameters such as the standard enthalpy and standard entropy data suggest the existence of hydrophobic interaction between LFH and surfactants.

Methyl red dye in the tuning of polypyrrole conductivity

Polypyrrole was prepared by the oxidation of pyrrole with iron(III) chloride in aqueous medium in the presence of methyl red dye. While the acid form of dye had no effect on the polypyrrole synthesis, the presence of its sodium salt increased the conductivity from 1–5 S cm−1 up to 84 S cm−1 for the polymerizations carried out with variable dye concentration at 20 °C. When the reaction temperature was reduced to −50 °C, the conductivity increased up to 104 S cm−1. At temperatures below −20 °C, the polymerization took place in frozen reaction medium, in ice. The morphology of polypyrrole was mainly globular and often converted to particles of irregular size and shape. It was concluded that one-dimensional morphology, nanotubes or nanofibers characteristic of polypyrrole, is not an automatic prerequisite for the high conductivity of this polymer.

Studies on the solvent extraction of indium (III) from aqueous chloride medium using Cyphos IL 104

With inimitable chemical and physical properties makes indium critical for a wide variety of high technology, chemical, metallurgical and pharmaceutical industries. As conferred by its location in the periodic table near the borderline between metals and non-metals; indium shows ductility, malleability, conductivity and transparency. In particular, the last two properties are the main reason for indium use in the semiconductor industry for flat panel displays and screens manufacturing by far the most important applications of indium in technical uses. The present study emphasized the extraction ability of a phosphonium based ionic liquid Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl) phosphinate) towards indium(III) extraction from acidic chloride medium. The effect of various parameters such as equilibrium time, acid concentration, chloride ion and hydrogen ion was investigated on In(III) extraction. Quantitative extraction of 97.2% was attained with 0.005 mol/L Cyphos IL 104 in toluene at 2.0 mol/L HCl. The effect of thermodynamic parameters i.e., ΔH°, ΔS° and ΔG° were also studied which suggested that the extraction process was endothermic and spontaneous that moves in the forward direction. Using 0.1 mol/L HCl, 100% of indium(III) was recovered from the loaded organic phase.

Separation and Recovery of Scandium and Yttrium from Aqueous Chloride Media by Integrated Ion Exchange Method

Separation and Recovery of Scandium and Yttrium from Aqueous Chloride Media by Integrated Ion Exchange Method