Hydrochloric Solution Research Articles

Ionic liquid based three-liquid-phase partitioning and one-step separation of Pt (IV), Pd (II) and Rh (III)

The present work reports an interesting phenomena that the addition of hydrophobic ionic liquid, [C4mim]PF6, into the oil–water two phase system of diisopentyl sulfide (S201)–nonane organic solutions and hydrochloric acid aqueous solutions containing Pt (IV), Pd (II) and Rh (III) chloric-complexing anions could induce the formation of a stable liquid–liquid–liquid three layered liquids coexisting medium for extraction and one-step separation of platinum, palladium and rhodium. The influences of H+ and Cl− concentrations in equilibrating aqueous solutions, the initial Pt (IV) concentration, the volume ratio of added [C4mim][PF6] to hydrochloric acid aqueous solution and the different salt ions in equilibrating aqueous solutions on the three-liquid-phase partitioning behaviors of three platinum metal ions were evaluated. The transferring of PtCl62- into the [C4mim]PF6 bottom phase in TLPS was proposed to be according with an anion exchange between PtCl62- and PF6- in ionic liquid. Therefore, the separated ionic liquid phase is not the solvent of organic extractants, but provides an extended separation capacity than the literature reported ionic liquid based two-phase extraction systems. The present work indicated that this ionic liquid based three-liquid system can be used to separate multi-metal coexisting solutions.

High performance thin layer chromatography–densitometry: A step further for quality control of cranberry extracts

A method for selective quantitation of catechin, proanthocyanidin (PAC) A2 and PAC-B1 in American cranberry (Vaccinium macrocarpon) extracts using high performance thin layer chromatography (HPTLC)–densitometry is presented. Methylene chloride/ethyl acetate/formic acid (6:10:1, v/v) as the mobile phase and 1% vanillin hydrochloric solution as staining reagent were used. In these conditions, three standards considered as quality markers, catechin, PAC-A2 and PAC-B1, were well resolved allowing simultaneous quantitation on one plate. All standards were quantified in the range of 0.7–5μg with RSD of repeatability and intermediate precision not exceeding 5%. Catechin, PAC-A2 and PAC-B1 profiles of cranberry extracts were analysed regarding global PAC amounts obtained by BL-DMAC assay. It appears clearly that HPTLC–densitometry process provides additional information which, combined with BL-DMAC results, allows qualitative and quantitative control of cranberry extracts. Particularly, densitometric assay highlighted degradation of PACs in a 7day-extract, leading to high overestimation with BL-DMAC protocol.

Effects of Boronizing Treatment on Corrosion Resistance of 65Mn Steel in two Acid Mediums

Abstract To explore the soil workability of rotary blade suitable for large tilling depth (over 20 cm) manufactured through boronizing treatment, this work focuses on the corrosion behavior of 65Mn steel after boronizing treatment in two acid mediums, i.e. the strong acidic medium that hydrochloric solution and the weak acidic that fertilizer-containing soil, and the comparison with existing technology of general rotary blade (lonnealing after overall quenching). The result shows that the corrosion resistance in the two acid mediums of 65Mn steel after boronizing treatment is remarkably improved. After 168 hours’ corrosion in the hydrochloric acid solution, the weight loss of boronizing-status sample is only 27.9% of that of lonnealing-status sample. Moreover, there is no obvious weight loss in boronizing-status sample after 168 hours’ corrosion in the fertilizer-containing soil, while the weight of lonnealing-status sample is lighter than the original weight after about 150 hours’ corrosion. The improvement of the corrosion resistance lies in the significant reduction of the anodization speed in strong acid medium and the effective prevention of phosphorization reaction in weak acidic medium.

Adsorption Properties and Inhibition of C38 Steel Corrosion in Hydrochloric Solution by Some Indole Derivates: Temperature Effect, Activation Energies, and Thermodynamics of Adsorption

The corrosion rates in the presence of some indole derivates, namely, 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane), as inhibitors of C38 steel corrosion inhibitor in 1 M HCl solution, were measured by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, in the range of temperatures from 25 to 55∘C. Results obtained revealed that the organic compounds investigated have inhibiting properties for all temperatures. The inhibition was assumed to occur via adsorption of the indole molecules on the metal surface. Adsorption of indole derivates was found to follow the Langmuir isotherm. The apparent activation energies, enthalpies, and entropies of the dissolution process and the free energies and enthalpies for the adsorption process were determined by potentiodynamic polarization and electrochemical impedance. The fundamental thermodynamic functions were used to collect important information about indole inhibitory behaviour.

Effects of Chicken Feet Gelatin and Wheat Fiber Levels on Quality Properties of Semi-dried Chicken Jerky

The aim of this study was to investigate the effect of chicken feet gelatin and wheat fiber levels on the quality character-istics properties of semi-dried chicken jerky. The obtained chicken feet gelatin swollen with hydrochloric solution (0.1 NHCl, pH 1.31±0.02) was dehydrated via freeze-drying. Six formulations of chicken jerky that were prepared, based on theratio of chicken meat, chicken feet gelatin and wheat fiber, were 100:0:0, 98:0:2, 99:1:0, 97:1:2, 98:2:0 and 96:2:2, respec-tively. The moisture content of semi-dried chicken jerky containing 2% wheat fiber was higher than that of jerky withoutthe added fiber (p<0.05); moreover, an increase in the content of chicken feet gelatin also increased the moisture content.The drying yield of the samples increased with an increase in chicken feet gelatin. In addition, the drying yield of samplescontaining 2% wheat fiber was higher (p<0.05) than those without the added wheat fiber. However, the shear force of thesamples significantly decreased with the increase in chicken feet gelatin content. Further, the shear force of the samplescontaining 2% wheat fiber was higher ( p<0.05) than those without the added wheat fiber. No significant differences, exceptfor color, were observed in the sensory analysis among the treatments.Key words: chicken feet, gelatin, fiber, semi-dried jerky

Preparation of the composite material of bioactive glass and chitosan for bone repair

The aim of this work was to develop a bioactive glass/chitosan (BG/CS) composite material for bone repair. Hydrochloric solution was properly mixed. Bioactive glass was added to make CS/BG mixed liquor. The microstructure and composition were observed and analyzed. The third-generation rabbit mesenchymal stem cells were inoculated into the stent. The adhesion of the stent was detected, and the proliferation of cells on the stent was detected. The compatibility between the stent and cells was evaluated. The size and shapes of the prepared CS/BG stents were consistent with moulds. Hydroxyapatite crystals gathered and no aggregation of BG was found. The rabbit mesenchymal stem cells adhered to the stent, and some cells extended and stretched out pseudopodia. Obvious proliferation of bone marrow stromal cells (BMSCs) was found on the stent. The CS/BG stent can be prepared by solution blending and freeze-drying technology. The prepared stents have good porosity, high mechanical strength and good cell compatibility. Key words: Bioactive glasses, chitosan, tissue engineering, bone fixation.

Controllable Interfacial Mass Transfer Intensification for Multi-liquid Phase Extraction of Platinum, Palladium and Rhodium from Wasted Auto-Catalysts

The main purpose of present review article is to summarize our previous efforts to develop a new three-liquid-phase extraction strategy for recovery and recycling of platinum, palladium and rhodium from the hydrochloric acid leach solutions of various wasted auto-catalysts. It was found that Pt, Pd and Rh can be separated and selectively enriched into the three different liquid phases of the proposed three-liquid-phase system (TLPS), respectively. The partitioning behaviors of Pt(IV), Pd(II), Rh(III) are controllable and have a close correlation with the phase-forming behaviours of TLPS. A microphase mass transfer mechanism was proposed to explain the differences in partitioning behaviours of three platinum metal ions. The self-assembly of amphiphlic extractant molecules in aqueous solutions result in the controllable enrichment of target metal ions by those separated microphase aggregates. The differences in interfacial mass transfer of three metals are due to a controllable microscopic interaction of platinum metal ions with the microphase aggregates. The TLPS provide a unique separation medium to control the interphase mass transfer of different metal ions. The separation selectivity of the three platinum metals was improved remarkably by using the three-liquid-phase extraction technique in comparison with the traditional liquid–liquid two phase extractions. The present researches highlight a potential possibility for future industrial application of the multiphase extraction for one-step separation of different target metals from complex mixtures.

Determination of cyromazine and melamine in chicken eggs using quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction coupled with liquid chromatography–tandem mass spectrometry

A rapid and sensitive method has been developed for the simultaneous detection of cyromazine and melamine in chicken eggs using the quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The optimal extraction solvent for the liquid–liquid extraction was 5mL of acetonitrile with a 0.1M hydrochloric acid aqueous solution (99.5:0.5, v/v). The extract was cleaned with 0.5g of anhydrous magnesium sulfate and 10mg of graphitized carbon black. The analysis of cyromazine and melamine was accomplished by combining the use of an anion exchange LC column with tandem mass spectrometry in the positive electrospray ionization mode with selected reaction monitoring mode (SRM). The detection limits were 1.6ngg−1 for cyromazine and 8ngg−1 for melamine, and the quantitation limits were 5.5ngg−1 for cyromazine and 25ngg−1 for melamine. The recoveries of cyromazine and melamine in the spiked egg samples were 83.2% and 104.6%, respectively, with an relative standard deviation (RSD) of less than 18.1%. The intra-day and inter-day precisions, represented by the RSD, ranged from 1.5% to 8.8% and 6.8% to 14.3%, respectively. The proposed method was tested by analyzing chicken eggs from the markets and from the veterinary medicine laboratory. The concentrations of cyromazine and melamine detected in these samples were in the range of 20–94ngg−1. The results demonstrated that the QuEChERS method combined with LC–MS/MS is a simple, rapid and inexpensive method for the analysis of cyromazine and melamine in eggs.

Hydrodeoxygenation of benzofuran over activated carbon supported Pt, Pd, and Pt–Pd catalysts

Activated carbon supported Pt, Pd, and Pt–Pd catalysts have been successfully prepared by incipient wet impregnation with a hydrochloric solution of PdCl2 and PtCl4. Hydrodeoxygenation of benzofuran was used as a probe reaction to investigate their catalytic properties. The activated carbon supported Pt–Pd catalyst was confirmed to form Pt–Pd alloy by X-ray diffraction. All the catalysts were active in the hydrodeoxygenation of benzofuran. Pd catalyst did not only give higher hydrogenation activity, but also showed faster deoxygenation rate than the Pt catalyst. The Pt–Pd catalyst with the mole ratio of Pd/Pt = 4 showed the highest catalytic activity among all of the catalysts. 2-Ethylcyclohexanone, which was not observed over the sulfide catalysts, was detected as a new oxygen-containing intermediate in the hydrodeoxygenation of benzofuran over the activated carbon supported Pt, Pd, and Pt–Pd catalysts. A ketone/enol isomerization reaction route is proposed to happen over the activated carbon supported noble metal Pt, Pd, and Pt–Pd catalysts.

Ion exchange equilibria in simultaneous extraction of platinum(II, IV) and rhodium(III) from hydrochloric solutions

Regularities of sorption extraction of platinum(II, IV) and rhodium(III) by anion exchangers of various physical and chemical structure in the presence of hydrochloric media were studied. It is established that AM-2B, Purolite A 500, and Purolite S 985 ionites adsorb complex anions of platinum metals employing mixed mechanism. A high affinity of the studied anionites for the studied complex anions of platinum and rhodium is established.

The effect of nickel on alloy microstructure and electrochemical behaviour of AA1050 aluminium alloy in acid and alkaline solutions

The study investigates the influence of nickel and magnesium additions to AA1050 aluminium alloy on the alloy electrochemical behaviour in sodium hydroxide and hydrochloric solutions under conditions relevant to industries that use alkaline etching as a standard surface treatment procedure and to the lithographic and electronic industries where surface convolution is assisted by pitting in hydrochloric acid. Scanning and transmission electron microscopes were used to characterize the intermetallic particles, and scanning Kelvin probe microscopy was utilised in monitoring the surface potential. Nickel is shown to be incorporated into second phase particles, which mostly consisted of Al3Fe and α-(AlFeSi) phases, resulting in enhanced cathodic activity on the aluminium surface. Consequently, the dissolution rates of the superpure aluminium, alloys without nickel addition and alloy with nickel addition are increased respectively in sodium hydroxide, and increased pitting is respectively promoted in hydrochloric acid. In contrast, the addition of magnesium to the alloy had negligible influence on the etching and pitting behaviour.

A thermodynamic and kinetic study on [PdCl4]2– complex formation with L-cystine

Complex formation of with L-cystine (H2CysS) has been studied in hydrochloric aqueous solutions (0.05–1 mol L−1 HCl) by UV-Vis spectroscopy combined with quantum chemical calculations. Our data suggest that L-cystine acts as a monodentate S-coordinating ligand in highly acidic solutions and no evidence of S–S bond fission was found to occur under the experimental conditions. Thermodynamic parameters for Pd(H4CysS) formation were determined: the monocomplex stability constant log K 1 = 3.3 (298 K), ΔH = −27 kJ mol−1, and ΔS = −29 JK−1 mol−1 (0.5 mol L−1 HCl). The experimental reaction rate law has been obtained: W = k[H4CysS2+][][Cl−]−0.86 and the values for the activation parameters have been determined: E a = 66 kJ mol−1, ΔH 1 = 63 kJ mol−1, and ΔS 1 = −77 JK−1 mol−1. The electronic absorption spectra (EAS) of the Pd(H4CysS) complex were computed using time-dependent density functional theory and the polarizable continuum model. The def2-TZVPP basis set (PBE0 and TPSS density functionals) provides good agreement between the experimental and theoretical EAS.

Preparation and characterization of a new glass system inhibitor for mild steel corrosion in hydrochloric solution

Phosphate glasses, having composition 50BaO–xV2O5–(50-x)P2O5, (0⩽x⩽40mol%), were prepared and characterized. The substitution of the P2O5 by V2O5 up to 10mol%, in the binary 50BaO–50P2O5 glass entrained an increasing on Tg; beyond this value a reverse trend was observed. However, spectroscopic investigations revealed a phosphate glass system depolymerisation by systematic conversion of metaphosphate chains PO3− into pyrophosphate P2O74− and into orthophosphate PO43−. Indeed, Above 10mol% V2O5 content, the system was highly depolymerized due to the formation of isolated PO43− structural units, resulting in poor cross-linking, making the glass system less rigid.The mild steel corrosion inhibition in 1M HCl by phosphate glass was investigated using electrochemical measurements. The results showed that these glasses act as a corrosion inhibitor in acidic medium and their inhibition efficiencies depend to the V2O5 content in the system. In addition, it is observed that the metaphosphate chains provided a better protection than pyrophosphate P2O74− and orthophosphate PO43−.

Electrochemical characterization of Zr-based thin film metallic glass in hydrochloric aqueous solution

Recently thin film metallic glass represents a class of promising engineering materials for structural applications. In this work, the Zr-based thin film metallic glass (TFMG) was fabricated on the Si and AISI 420 substrates using a Zr–Cu–Ni–Al alloy and pure Zr metal targets by a pulsed DC magnetron sputtering system. The chemical compositions, crystalline structures, microstructures and corrosion behavior in hydrochloric (HCl) aqueous solutions of Zr-based TFMGs were investigated. The results showed that the surface morphologies of Zr-based TFMG were very smooth. A compact and dense structure without columnar structure was observed. The amorphous structure of Zr-based TFMG was characterized by the X-ray diffractometer and transmission electron microscopy analyses. After the potentiodynamic polarization test, the better corrosion resistance was achieved for the Zr-based TFMG coated AISI 420 in 1mM HCl aqueous solution. Based on the surface morphologies and chemical analysis results of the corroded surfaces, the pitting, crevice corrosion and filiform corrosion were found. The corrosion mechanisms of the Zr-based TFMG were discussed in this work.

Adsorption and Inhibitive Effects of 2-Thiobenzylbenzimidazole (TBBI) at Aluminium Alloy AA3003/ 1M Hydrochloric Acid Interface

The interfacial behavior of 2-Thiobenzylbenzimidazole (TBBI) between aluminium alloy AA 3003 and 1M hydrochloric acid solution was investigated by mass loss technique. Mass loss is concentration and temperature dependent. The influence of temperature has been studied in the absence and in presence of TBBI in the hydrochloric solution in the range 35-55oC. Adsorption isotherms models including Langmuir, Temkin, Freundlich and El-Awady were tested. It was found that the inhibitor adsorbs on the metal according to the modified Langmuir adsorption isotherm. Some thermodynamic adsorption parameters (�G ° �H ° ,�S ° ) as well as activation parameters including apparent activation energy (Ea), change in activation enthalpy (� � ) and change in activation entropy (� � ) have been calculated and analyzed. Furthermore the DubininRaduskevitch model has been used to distinguish between chemisorption and physisorption. The properties most relevant to the potential action as a corrosion inhibitor of TBBI have been calculated: highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE), dipole moment (µ) and charges on the adsorption centers (S, N) and C atoms in benzimidazole and benzyl rings. These calculations were performed using the Gaussian Research Article

Synthesis and Inhibition Performance Evaluation of Two Sebacic Acid Imidazoline Quaternary Ammonium Salts

Two sebacic acid imidazoline quaternary ammonium salts,sebacic acid-salicylic acid imidazoline quaternary ammonium salts(SSAI) and sebacic acid imidazoline quaternary ammonium salts(SAI),were synthesized and their inhibition action and adsorption behavior on N80 steel in 1 mol/L hydrochloric solution were investigated by means of mass loss and electrochemical techniques.It was showed that the two compounds had good corrosion inhibition for N80 steel in 1 mol/L HCl solution.SSAI was found to have a superior inhibition efficiency to SAI.Both SSAI and SAI were mixed-type inhibitors and mainly inhibited anode process against N80 steel in 1 mol/L HCl solution.The experimental results revealed that the adsorption processes were exothermic reaction and belong to chemical adsorption.

Unlabeled multi tumor marker detection system based on bioinitiated light addressable potentiometric sensor

Multi biomarkers' assays are of great significance in clinical diagnosis. A label-free multi tumor markers' parallel detection system was proposed based on a light addressable potentiometric sensor (LAPS). Arrayed LAPS chips with basic structure of Si(3)N(4)-SiO(2)-Si were prepared on silicon wafers, and the label-free parallel detection system for this component was developed with user friendly controlling interfaces. Then the l-3,4-dihydroxyphenyl-alanine (L-Dopa) hydrochloric solution was used to initiate the surface of LAPS. The L-Dopa immobilization state was investigated by the theoretical calculation. L-Dopa initiated LAPS' chip was biofunctionalized respectively by the antigens and antibodies of four tumor markers, α-fetoprotein (AFP), carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9) and Ferritin. Then unlabeled antibodies and antigens of these four biomarkers were detected by the proposed detection systems. Furthermore physical and measuring principles in this system were described, and qualitative understanding for experimental data were given. The measured response ranges were compared with their clinical cutoff values, and sensitivities were calculated by OriginLab. The results indicate that this bioinitiated LAPS based label-free detection system may offer a new choice for the realization of unlabeled multi tumor markers' clinical assay.

Three-liquid-phase partition behaviors of Pt(IV), Pd(II) and Rh(III): Influences of phase-forming components

Three-liquid-phase extraction is a new technique to separate Pt(IV), Pd(II) and Rh(III) from their hydrochloric acid leaching solutions. The selection of phase-forming components is crucial to induce a stable three-liquid-phase system and the controllable three-phase partitioning of Pt(IV), Pd(II) and Rh(III). In present work, various phase-forming salts with different cations and anions, amphiphilic block copolymers with different molecular weight and PPO content, organic extractants with different metal-selective functional groups were investigated to discuss their influence on three-phase mass transfer behaviors of three platinum metals. Experimental results indicated that the formation of three-layered coexisting liquid phases in system of S201/nonane-EOPO2500-Na2SO4-H2O resulted in three-liquid-phase selective partitioning of Pt(IV), Pd(II) and Rh(III). Most of Pt(IV) and Pd(II) were extracted into EOPO-rich phase with the two-phase splitting of EOPO2500-Na2SO4 mixtures, whereas Rh(III) remained in bottom salt aqueous phase. Addition of S201/nonane promoted the separation between Pd(II) and Pt(IV), and most of Pd(II) transferred from EOPO-rich phase into S201 organic top phase of TLPS. Under the optimal conditions, 98.5% of Pd(II), 90.8% of Pt(IV) and 87.1% of Rh(III) were enriched into the top organic, middle polymer and bottom salt aqueous phases, respectively.

UTILIZATION OF RICE HUSK AS RAW MATERIAL IN SYNTHESIS OF MESOPOROUS SILICATES MCM-41

The research about synthesis and characterization of MCM-41 from rice husk has been done. Silica (SiO2) was extracted from rice husk by refluxing with 3M hydrochloric solution at 80 °C for 3 h. The acid-leached rice husk was filtered, washed, dried and calcined at 650 °C for 6 h lead the rough powder of rice husk silica with light brown in color. Characterization was carried out by X-ray diffraction (XRD) and FTIR spectroscopy method. Rice husk silica was dissolved into the sodium hydroxide solution leading to the solution of sodium silicate, and used as silica source for the synthesis of MCM-41. MCM-41 was synthesized by hydrothermal process to the mixture prepared from 29 g of distilled water, 8.67 g of cetyltrimethyl ammonium bromide (CTMAB), 9.31 g of sodium silicate solution, and amount mL of 1 M H2SO4. Hydrothermal process was carried out at 100 °C in a teflon-lined stainless steel autoclave heated in the oven for 36 h. The solid phase was filtered, then washed with deionised water, and dried in the oven at 100 °C for 2 h. The surfactant CTMAB was removed by calcination at 550 °C for 10 h with heating rate 2 °C/min. The as-synthesized and calcined crystals were characterized by using FTIR spectroscopy, X-ray diffraction and N2 physisorption methods. In order to investigate the effect of silica source, the same procedure was carried out by using pure sodium silicate as silica source. It was concluded that silica extracted from rice husk can be used as raw materials in the synthesis of MCM-41, there is no significant difference in crystallinity and pore properties when was compared to material produced from commercial sodium silicate.

The corrosion inhibitory property of N ,N -bis(2-benzimidazolylmethyl)amine for Q235 steel

The main purpose of this paper is to systematically evaluate the anti-corrosion property of N,N-bis(2-benzimidazolylmethyl)amine (IDB), which is a novel good thermal stabilized inhibitor in acidic medium. Results obtained from electrochemical tests and corrosion surface morphology analyses reveal that IDB performs excellently as corrosion inhibitor for Q235 steel in 1 mol/L hydrochloric acid corrosive solution. Potentiodynamic polarization measurements show that IDB inhibits both the anodic and cathodic processes of corrosion and exhibits as a mixed-type inhibitor. Besides, the inhibiting efficiency (IE%) and consequently the degree of surface coverage (θ) increase with the inhibitor concentration rising. And when the concentration is 20 × 10−5 mol/L, the corrosion inhibition effect is best to reach 96.39%. The adsorption of inhibitor on Q235 steel is found to obey the Langmuir adsorption isotherm, and the calculated Gibbs free energy demonstrates that IDB spontaneously adsorbs and forms a protective chemisorbed film on Q235 steel to restrain its corrosion. Hereby, IDB will become a promising corrosion inhibitor in further.