Zinc In Acid Research Articles

Solubility Studies of Sulfates of Copper, Zinc and Cobalt in Phosphoric Acid at 30 ºC

Present study reports the isothermal experiments conducted at 30 ºC to ascertain the solubility of copper, zinc and cobalt sulfates in phosphoric acid. The solubility diagram of CuSO4-H3PO4-H2O system is shown to have one branch, this is equivalent to the discharge of copper sulfate pentahydrate into the equilibrium solid phase. The solubility diagrams of zinc and cobalt sulfates have two branches of salt crystallization, corresponding to the release of hexahydrates and monohydrates of zinc and cobalt with increasing phosphoric acid content, saturated solutions in the ZnSO4-H3PO4-H2O and CoSO4-H3PO4-H2O systems become more viscous and denser, reaching a maximum at the transition point, while these indicators in the CuSO4-H3PO4-H2O system only increase.

Green nanoparticles as a sustainable inhibitor to attenuate acid corrosion of zinc

Primary step of work is to synthesis and characterize of nanoparticles of biopolymer Bovine Serum Albumin (BSA-Np). Then it is used as green inhibitior for corrosion mitigation of zinc in sulfamic acid (NH2SO3H). BSA-Np was synthesized by the microwave-assisted nanoprecipitation method and characterized by XRD, UV–Visible, FT-IR, TEM, EDX and Zeta potential measurements. Corrosion inhibition studies were performed by electrochemical techniques like potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Conditions were established to obtain maximum inhibition efficiency by varying experimental conditions like concentration of inhibitor and temperature. Kinetic and thermodynamic parameters were computed and discussed in detail. Experimental results were fitted into appropriate adsorption isotherms and suitable mode of adorption was predicted. Adsorption of BSA-Np onto metal surfaces was complemented and substantiated by SEM, EDX and AFM measurements. More than 90% of inhibition efficiency could be achieved. Nanoparticles of biopolymer was emerged as sustainable inhibitor for corrosion mitigation of zinc.

Selective catalytic hydrodebromination of 2,3,4,5-tetrabromothiophene with hydrogen on a palladium catalyst

A study on the Pd-catalyzed hydrodebromination of 2,3,4,5-tetrabromothiophene (1) to 3,4-dibromothiophene (2) is reported. The effect of the solvent nature, main agent, temperature and concentration of 1 on the yield of 2 was studied. Optimal conditions of the process were found: a 5 % Pd/Sibunit catalyst constituting 10 % of the substrate weight, a temperature of 80 °С, a pressure of 0.7 MPa, dimethyl formamide with the addition of triethylamine as the main agent in the amount of 2.2 equiv per 1 equiv of the initial substance 1, and the yield of 2 constituting up to 97.5 %. It was shown that the catalyst could be reused with the preservation of the high yield of 2. In comparison with the conventional method of chemical reduction of 1 under the action of zinc in acetic acid, the novel method ensures high output and low wastes.

Spectroscopic and Surface Analysis Data for Corrosion of Zinc in Sulfamic Acid—Electrochemical Approach

Spectroscopic and Surface Analysis Data for Corrosion of Zinc in Sulfamic Acid—Electrochemical Approach

Effects of Supplementation of Zinc, Manganese, or Copper and Different Phytase Levels in Serum and Bone Acid and Alkaline Phosphatases of Broiler Chicks

The knowledge of biological trace minerals and phytase requirements for modern broiler genotypes is not established and the pressure to reduce their usage in animal feeding due to environmental issues is increasing. Here, the alkaline phosphatase (ALP) and tartarate-resistant acid phosphatase (TRAP) of the tibia and serum of broilers fed with diets containing various levels of phytase and reduced levels of zinc, manganese, and copper was evaluated. The experiment was performed using 1,200 male Cobb broilers raised according to standard commercial husbandry techniques. Data were analyzed as a 4×3 factorial arrangement with four concentrations of zinc (0.34, 0.49, 0.64, and 0.79 ppm), manganese (0.18, 0.43, 0.68, and 0.93 ppm), or copper (0.09, 0.12, 0.15, and 0.18 ppm) and three concentrations of phytase (0, 500, and 1,000 FTU/kg) for age periods of 1-21 and 36-42 days. While the dietary supplementation with copper did not induce a significant effect in bone tissue biochemical markers, serum TRAP activity of 42-day old broilers increased with higher copper levels. Increasing dietary zinc levels linearly increased ALP activity in tibia growth, suggesting that zinc is essential for longitudinal bone growth. Phytase significantly promoted the increase of TRAP and ALP activities, suggesting that manganese increased growth plate activity, accelerated calcification, and remodeled the newly formed tissue into trabecular bone. Although not every enzymatic activity was affected by the treatments, the phytase use, along with trace minerals, improved the animal response to the rapid growth required nowadays and provided the nutrients for adequate bone metabolism.

Efficient recovery of valuable metals from lead-zinc smelting by-products by ultrasonic strengthening

As a byproduct of lead and zinc smelting, zinc oxide dust often contains abundant valuable metals such as zinc and germanium. To improve the leaching of zinc and germanium in sulfuric acid, the correlation between germanium and other elements in zinc oxide dust, the phase composition of the main elements, and Eh-pH dominant area of germanium were analyzed. Finally, ultrasonic waves and potassium dichromate were added to enhance the leaching of zinc and germanium in the leaching process. The results show that the best recoveries of zinc and germanium are 99.25 % and 90.44 %, respectively, under the optimum conditions. Compared with the existing process, the leaching rate is increased by 8 ∼ 10 % and the leaching time is reduced by more than 50 %. There are fewer impurities in the leaching residue after leaching, and the lead content is about 50 % and can be directly recycled back into the lead smelting process for recycling. In conclusion, the oxidation leaching of zinc and germanium from zinc oxide dust with potassium dichromate under ultrasound proves to be efficient, economical and practical.

Investigation of the effect of the addition H2O2 on the general corrosion of brass in hydrochloric acid

In this paper, the influence of hydrochloric acid and the addition of oxidizing agents on the rate of general corrosion of brass was investigated. For comparison, the corrosion rate of copper and zinc in hydrochloric acid and in hydrochloric acid with oxidizing agent was also tested. The Taffel extrapolation method was used to examine the general corrosion of brass, copper and zinc. The Taffel extrapolation method involves scanning potential of the working electrode of ±250 mV in relation to its open-circuit otential (EOCP), at a speed of 0.5 mVs-1. Investigation of corrosion was conducted in a corrosion cell according to the ASTM G5 (ASTM G5-94) standard, on a potentiostat/galvanostat instrument, Princeton Applied Research, model 263A-2, with PowerCORR® software, which is part of the Power Suite softwere package. The tests were performed at room temperature, 20±1°C. The results show that the corrosion rate of brass is higher in hydrochloric acid with oxidizing agent than the corrosion rate of brass in hydrochloric acid. Examining the effect of hydrochloric acid and the addition of oxidizing agent on the rate of general corrosion of brass, it was found that the corrosion of brass has caused the zinc contained in it. Corrosion of zinc is highest in 0.1 M HCl + 0.1 M H2O2 compared to corrosion of brass and copper in 0.1 M HCl + 0.1 M H2O2, where corrosion of copper is lowest in 0.1 M HCl + 0.1 M H2O2.

Sodium dodecyl benzene sulfonate (SDBS) and N,N-dimethyldodecan-1-amine oxide (DDAO) in single and mixed systems as corrosion inhibitors of zinc in hydrochloric acid

Abstract The influence of surfactant synergism between sodium dodecyl benzene sulfonate (SDBS) and N,N-dimethyldodecan-1-amine Oxide (DDAO) on zinc corrosion in 0.05 M hydrochloric acid (HCl) solutions at 25 °C was investigated. Firstly, solutions of SDBS and DDAO with mole fractions of 0.00, 0.25, 0.50, 0.75 and 1.00 were prepared and their surface tension and critical micelle concentration (CMC) values in water and in 0.05 M HCl were measured as a function of total surfactant concentration. The SDBS/DDAO mixed system exhibited a strong synergism in 0.05 M HCl with a highly negative interaction parameter β (average β = −23.46), according to regular solution theory. Secondly, the adsorption of single surfactants SDBS and DDAO and SDBS/DDAO surfactant mixture on 2.0% zinc powder was investigated by the depletion method to find out the role of synergism in the adsorption tendency of these surfactants on the zinc surface and thus their corrosion inhibiting effect. The adsorption tendency of single surfactant and the mixed surfactant systems onto 2.0% zinc powder followed the order: SDBS > 0.75 SDBS/0.25 DDAO ≈ 0.25 SDBS/0.75 DDAO > DDAO > 0.50 SDBS/0.50 DDAO. Finally, the corrosion of zinc was investigated using the potentiodynamic polarization technique. It was found that SDBS and DDAO act as efficient corrosion inhibitors for zinc in 0.05 M HCl solution with increasing corrosion inhibition efficiency when they are mixed. Additionally, images of scanning electron microscopy were obtained for zinc sheets in solutions containing single and mixed SDBS/DDAO surfactants in the presence and absence of 0.05 M HCl. The microscopic images show an improvement in the protection of the zinc surface against acid attack in the presence of single and mixed SDBS/DDAO surfactants.

Glycogen nanoparticles as a potential corrosion inhibitor

Biological macromolecules are proven to be potential green corrosion inhibitors because of their outstanding structural features and eco-friendliness. This study is aimed at enhancing their corrosion mitigation capabilities by converting them into nanoparticles. This is the first work where nanoparticles of biological macromolecules are exploited for corrosion mitigation studies. Glycogen nanoparticles (GLY-Np) were synthesized by microwave-mediated nanoprecipitation method and characterized by ATR–FTIR, XRD, UV–Visible Spectroscopy, FESEM analysis, EDX, TEM, and Zeta potential measurements. They are used as an eco-friendly inhibitor for corrosion control of zinc in sulfamic acid (NH2SO3H). The electrochemical study was a primary experimental tool employed for corrosion rate measurement. Conditions were optimized to obtain maximum inhibition efficiency by varying concentrations of inhibitor and temperature. Activation and thermodynamic parameters were evaluated and discussed in detail. A suitable adsorption isotherm was proposed to fit the experimental results. Adsorption of the inhibitor was confirmed by SEM, EDX, and AFM techniques. The inhibition efficiency of 92% was obtained for 0.02 gL−1 GLY-Np. Thus, GLY-Np turned out to be an effective green inhibition with economic benefits.

CYCLOADDITION OF NITRONES TO 1,3-DIARYLPROPENONES AND SUBSEQUENT TRANSFORMATIONS OF THE RESULTING ISOXAZOLIDINES

Ketonitrones containing two ester groups react regio- and stereoselectively with 1,3-diarylpropenones to form isoxazolidines with ester groups at position 3 of the ring. The action of zinc in acetic acid on these isoxazolidines causes opening of the ring with the formation of 3-amino alcohols, the subsequent cyclization of which leads to polysubstituted lactones. Reduction of the benzoyl group of isoxazolidine with sodium borohydride leads, as a result of subsequent transformations, to the formation of substituted 1,3,4-triaryl-6-oxodihydro-1 H ,3 H -furo[3,4- c ]isoxazole-6a(6 H )-carboxylates as single diastereomers. Authors: Ekaterina V. Sirotkina, Mariia M. Efremova, Galina L. Starova, Mikhail A. Kuznetsov, Alexander P. Molchanov*

Cycloaddition of nitrones to 1,3-diarylpropenones and subsequent transformations of the resulting isoxazolidines

Ketonitrones containing two ester groups react regio- and stereoselectively with 1,3-diarylpropenones to form isoxazolidines with ester groups at position 3 of the ring. The action of zinc in acetic acid on these isoxazolidines causes opening of the ring with the formation of 3-amino alcohols, the subsequent cyclization of which leads to polysubstituted lactones. Reduction of the benzoyl group of isoxazolidine with sodium borohydride leads, as a result of subsequent transformations, to the formation of substituted 1,3,4-triaryl-6-oxodihydro-1H,3H-furo[3,4-c]isoxazole-6a(6H)-carboxylates as single diastereomers.

Intramolecular cyclization of 2-(heteroarylsulfanyl)-N-(3-oxoalkenyl)acetamides: synthesis of 3-(heteroarylsulfanyl)- and 3-sulfanylpyridin-2(1H)-ones

The reaction of 2-chloro-N-(3-oxoalkenyl)acetamides with 1,3-benzothiazole-2(3H)-thione, 1,3-benzoxazole-2(3H)-thione, and 1-methyl-1,3-dihydro-2H-benzimidazole-2-thione led to the formation of 2-(heteroarylsulfanyl)-N-(3-oxoalkenyl)acetamides. By the action of a base, these compounds were converted into pyridin-2(1H)-ones containing a divalent sulfur atom in position C-3 bonded to a heterocyclic ring. Bromination, nitration, alkylation of 3-(1,3-benzothiazol-2-ylsulfanyl)pyridin-2(1H)-ones have been studied. The action of zinc in acetic acid transformed these compounds into 3-sulfanylpyridin-2(1H)-ones.

Synthesis and Antitumor Activity of New 5-Ylidene Derivatives of 3-(Furan-2-ylmethyl)-2-sulfanylidene-1,3-thiazolidin-4-one

Reactions of 3-(furan-2-ylmethyl)-2-sulfanyidene-1,3-thiazolidin-4-one with aromatic and heterocyclic aldehydes afforded a series of previously unknown 5-[(het)arylmethylidene]-3-(furan-2-ylmethyl)-2-sulfanylidene-1,3-thiazolidin-4-ones. Treatment of 3-(furan-2-ylmethyl)-2-sulfanylidene-1,3-thiazolidin-4-one with thionyl chloride gave in a good yield 3,3′-bis(furan-2-ylmethyl)-2,2′-disulfanylidene-5,5′-bi-1,3-thiazolidinylidene-4,4′-dione which was reduced with zinc in acetic acid to 3,3′-bis(furan-2-ylmethyl)-2,2′-disulfanylidene-5,5′-bi-1,3-thiazolidine-4,4′-dione. The synthesized compounds were screened for antitumor activity.

Radiochemical Assessment of Uranium in Locally Used Marbles

A sensitive method is used for the extraction and determination of soluble uranium in locally used marble has been developed. Isobutyl Methyl Ketone (IBMK) was used as extractant and 0.02 % (w/v) Arsenazo (III) as a chromogenic reagent. The present study assesses the gross radioactivity and extractable uranium in marble samples. A Multichannel Analyzer (MCA) coupled with NaI (Tl) crystal detector was used for the measurement of gross radioactivity whereas spectrophotometer was used to estimate the uranium contained in sample with the help of Arsenazo (III). The extraction involved the adjustment of pH at 0.9. The efficient extraction was achieved by the addition of at least 10 g of Al (NO3)3. This method involved the reduction of UO2 (+2) to U (IV) by using granulated Zinc in concentrated hydrochloric acid. The physical measurements showed the presence of gross radioactivity in the range 266.19 Bq/kg to 644.268 Bq/Kg while the chemical analysis showed the uranium concentration in the range of 0.02ppm to 0.06 ppm.

Propoxylated Fatty Esters as Safe Inhibitors for Corrosion of Zinc in Hydrochloric Acid

The inhibiting action of nonionic surfactants, namely, propoxylated fatty esters (PFE) with different number of propylene oxide toward the corrosion of Zn in 0.1 M HCl solutions was investigated. Four techniques were used in this study such as weight loss, galvanostatic polarization, potentiodynamic anodic polarization and electrochemical impedance spectroscopy. The inhibition efficiency of PFE compounds increases by increasing the concentrations of PFE, number of propylene oxide unit and with lowering temperature. The inhibition was interpreted by adsorption of PFE molecules on the Zn surface according Temkin’s isotherm. Galvanstatic polarization indicated that the PFE acts as a mixed type inhibitor. PFE molecules inhibit the pitting corrosion of Zn in a solution containing Cl– ions by moving the pitting potentials into a more noble direction. The activation thermodynamic parameters such as $$E_{{\text{a}}}^{*}$$, ΔH* and ΔS* are calculated and explained.

Maltodextrin for corrosion mitigation of zinc in sulfamic acid: Electrochemical, surface and spectroscopic studies

Maltodextrin (MLD), a biopolymer was introduced as a novel green inhibitor to mitigate the corrosion of zinc in sulfamic acid medium by weight loss and by electrochemical methods. Conditions were optimized to obtain maximum inhibition efficiency. Thermodynamic parameters were evaluated. The surface morphology was studied by SEM, EDX, AFM analysis. Adsorption of inhibitor was re-affirmed by FT-IR spectroscopy, Atomic absorption spectroscopy (AAS), Raman spectroscopy and powder X-ray diffraction (XRD) analysis. Maximum efficiency of 72% was observed for the addition of 400 ppm of MLD. Surface morphology and spectroscopic studies confirmed the adsorption of MLD onto the surface of zinc. Results obtained by classical and electrochemical methods are in good agreement with one another. Maltodextrin emerged as an effective eco -friendly green inhibitor.

Effect of Addition of Other Acids into Butyric Acid on Selective Leaching of Zinc from Basic Oxygen Steelmaking Filter Cake

The selective leaching of zinc over iron from basic oxygen steelmaking (BOS) filter cake was investigated using mixtures of butyric acid with acetic and/or propionic acid, HCl, or H2SO4. The main focus was to assess the effects of other acids on the zinc and iron leaching in butyric acid. The results show that slight reduction of zinc leaching and increase in iron leaching may take place with addition of acetic and propionic acids, causing a minor decrease in the selectivity of zinc leaching over iron. Intermittent addition of H2SO4 and HCl was required to control the pH to be not less than that of pure butyric acid solution. Overall, an excellent selectivity can be maintained with the butyric acid–other acid mixtures. The results demonstrate the feasibility to use raw butyric acid without purification or waste butyric acid containing other impurity acids for leaching of zinc from the BOS filter cake to be recycled. Using high content of H2SO4 in leaching is not recommended because it has a more detrimental effect on the selectivity of zinc leaching and may cause deposition of CaSO4 in the leaching residue which may increase the SO2 or CO2 emission in later high-temperature recycling processes.

Competent inhibitor for the corrosion of zinc in hydrochloric acid based on 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine

A novel compound, 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine (BPEP), was synthesized and confirmed by NMR and IR spectroscopy. BPEP was examined as an inhibitor for the corrosion of zinc electrode in 1.0 M HCl. The inhibition efficiency of BPEP was assessed through various techniques such as hydrogen evolution, galvanostatic polarization, potentiodynamic anodic polarization, and electrochemical impedance spectroscopy. The inhibiting action of BPEP was explained in terms of the formation of a stable complex between zinc ions and BPEP and then adsorbed onto the zinc surface. The formation of the complex was established by FT-IR spectroscopy. A conductometric titration indicated that the stoichiometry of Zn+2:BPEP (metal:ligand) is 1:1. The adsorption follows the Langmuir isotherm. The Galvanostatic polarization measurements have shown that the BPEP molecule acts as a mixed-type inhibitor. The pitting potential shifted in the noble direction, indicating that the inhibition of pitting corrosion of zinc in the presence of BPEP.The activation energy and themodyanamic parameters of the adsorption process were calculated and have been explained.

Cetyltrimethyl Ammonium Bromide as Corrosion Inhibitor for Zinc Used in Hydrochloric Acid

A compound inhibitor composed of cetyltrimethyl ammonium bromide (CTAB) and bromohexadecyl pyridine was tested as corrosion inhibitor for zinc in hydrochloric acid. The results of static coupon test show that the compound inhibitor can effectively protect zinc from corrosion and the best concentration ratio is CTAB 50 mg/L and bromohexadecyl pyridine 200 mg/L. The polarization results show that the compound inhibitor will cause a negative shift of E0 of zinc in hydrochloric acid. The EIS (electrchemical impedance spectra) results show that the inhibitor leads to a bigger radius and has one time constant. SEM results show that the CTAB and bromohexadecyl pyridine form a uniform and compact membrane on the surface of zinc that can protect zinc from corroding effectively.

5-[4'-(1, 3-BENZOTHIAZOL-2-YL)PHENYL]-2,3,7,8,12,18-HEXAMETHYL-13,17-DI-N-AMYLPORPHIRIN: SYNTHESIS, COORDINATION PROPERTIES AND SORPTION ON POLYPROPYLENE MATERIALS

5-[4'-(1,3-Benzothiazol-2-yl)phenyl]-2,3,7,8,12,18-hexamethyl-13,17-di-n-amyl-porphirin was synthesized and its coordination properties with the acetates of cobalt, copper and zinc in acetic acid and pyridine were investigated. On the base of data obtained the kinetic parameters of the complexation reaction were calculated. It was established that in acetic acid the increase in a rate of reaction of complexation is observed in the series: Co+2 < Zn+2 < Cu+2, while the activation energy decreases by a factor of 1.5-2 and the value of preexponential factor is significantly increased. The pyridine is an inverse relationship. Copper and cobalt complexes of porphyrin were used for surface modification of chemically activated polypropylene materials. Based on the electronic spectra, the effective surface concentration of immobilized porphyrin molecules was calculated. It was shown, that there is a direct dependence of the amount of grafted metal complexes on the surface structure of the polymer-carrier and conditions of immobilization of macromolecules. The obtained modified materials were tested for bioactivity with the use of an aqueous suspension of agar-agar infected on the following cultures: Staphylococcus aureus (gram-positive culture) and Escherichia coli (gram-negative culture) in the microbial load of 106 cells/ml. The results of the studies were showed that the obtained materials have bacteriostatic resistance to all types of used pathogens.Forcitation:GornukhinaO.V., VershininaI.A., KiselevA.N., KuvshinovaE.M., SyrbuS.A., GolubchikovO.A. 5-[4'-(1, 3-Benzothiazol-2-yl)phenyl]-2,3,7,8,12,18-hexamethyl-13,17-di-n-amylporphirin: synthesis, coordinationpropertiesandsorptiononpolypropylenematerials. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 1. P. 49-54