Mixture Of HCl Research Articles

ChemInform Abstract: The Synthesis, Structure and Properties of a New Compound with 1D Linear Chain Arsenomolybdate Anion Building Block.

AbstractThe new compound [Cu(bipy)]2 [H2As2Mo2O14] is hydrothermally synthesized from a mixture of MoO3, CuCl2, Na3AsO4, bipy, HCl, and H2O (autoclave, pH 3.5, 160 °C, 6 d; 58% yield).

The deep eutectic melt of sorbitol and metformin hydrochloride: synthesis of 3-substituted 2-aminonaphtho[2,3-b]furan-4,9-diones and their photophysical properties

The low-melting deep-eutectic mixture of sorbitol and metformin HCl was successfully employed as a recyclable solvent for promoting the synthesis of benzofuroquinone dyes.

Determination of Inorganic Contaminants in Electrical and Electronic Equipment after Digestion Using Microwave-Assisted Single Reaction Chamber

A method for digestion of plastics from waste of electrical and electronic equipment (WEEE) was developed using the microwave-assisted wet digestion in single reaction chamber (MAWD-SRC). The determination of As, Cd, Co, Cr, Cu, Ni, Pb, Sb and Zn by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP OES) was carried out after sample digestion. Mercury was determined by flow-injection cold vapor generation coupled to inductively coupled plasma mass spectrometry (FI-CVG-ICP-MS). Results obtained using MAWD-SRC for sample preparation were compared with those obtained using microwave-assisted wet digestion (MAWD) at high pressure. Acid mixtures (HNO3 or HNO3 + HCl) were evaluated and feasibility for further inorganic contaminants determination by ICP-MS and ICP OES was demonstrated. Sample preparation by MAWD-SRC using HNO3 + HCl mixture resulted in better digestion efficiency in comparison to MAWD. In addition, lower limits of quantification were obtained using MAWD-SRC due to the higher sample mass that can be digested (500 mg). The combination of HNO3 and HCl for digestion showed to be crucial for quantitative recovery of some elements, as Cr and Sb. Agreement with certified values was better than 96%.

Akumulasi Timah Hitam dalam Daging dan Tulang Ayam Kampung dan Ayam Negeri

Lead is a heavy metal polluting the environment, and its accumulation in animal or human bodies canhave neurotoxic and nephrotoxic effects on animals and human. Lead-contaminated chicken meat can bethe source of lead to human. Lead exposure to human can be assessed by measuring its concentration andaccumulation in chicken body parts and analyzing chicken consumption patterns. This study was conductedto measure lead concentrations in chicken body parts and to estimate lead exposure caused by consumptionof chicken body parts (breast, legs, wings) and tissues (meat, skin, cartilage, spongy bones). Samples wereextracted by using aqua regia digestible method with a mixture of HCl: HNO3 (3:1; v/v) and leadconcentrations were measured by the Atomic Absorption Spectrophotometry (AAS) method. The leadconcentrations in chicken tissues varied from< 0.01 to 1.81?g.g-1dry weight.The average concentrations oflead in chicken tissues were lower than the recommended safety level of lead in chicken meat (1.0?g.g-1),except for the breast cartilage (1.03?g.g-1). The lowet accumulation level 2.6 ?g g-1 was found in domesticchicken wings while the highest of 32.9 ?g g-1 was found in broiler chicken breast (total of meat, skin,cartilage). Based on the data of lead accumulation in chicken tissues, a polynomial equation describing theprobability (P) to be exposed to certain amount of lead in chicken tissues (A, in ?g) was determined as P =-(1 x 10-3)A2 + (6,4 x 10-2)A.

Development of 77Ge/77As parent-daughter system for periodic removal of 77As for environmental sanitation and biochemical purposes

Abstract A simple method was developed for the separation of radioactive 77As from neutron irradiated natural GeO2 samples for environmental and biochemical studies. The method is based on the volatility of GeCl4. The GeCl4 was co-evaporated from the reaction mixture with an azeotropic mixture of HCl and water, and immediately condensed into a separate finger part of the special glass apparatus which was cooled by liquid nitrogen. By inverting the room temperature and the deep frozen parts of the glass equipment after three half-lives of the 77Ge the separation process can be repetitive, getting a special type of 77Ge/77As parent-daughter system. The radionuclidic purity of the remaining As fraction was found to be 99.95%. Its yield, however, drastically decreased in the second and subsequent separations.

Preparation of diffusion dialysis membrane for acid recovery via a phase-inversion method

Herein, the preparation of anion exchange membrane (AEM) from brominated poly(2,6-dimethyl 1,6-phenylene oxide) BPPO and dimethylaniline (DMA) by phase-inversion process is reported. Anion exchange membranes (AEMs) are prepared by varying the DMA contents. Prepared AEMs show high thermal stability, water uptake (WR) around 202% to 226%, dimensional change ratios of 1.5% to 2.6% and ion exchange capacities (IECs) of 0.34 mmol/g to 0.82 mmol/g with contact angle of 59.18° to 65.15°. These membranes are porous in nature as confirmed by SEM observation. The porous property of membranes are important as it could reduce the resistance of transportation of ions across the membranes. They have been used in diffusion dialysis (DD) process for recovery of hydrochloric acid (HCl) from the mixture of HCl and ferrous chloride (FeCl2). Presence of ¯N+(CH3)2C6H5Br &$175;as a functional group in membrane matrix facilitates its applications in DD process. The dialysis coefficients of hydrochloric acid (UH) of the membranes are in range of 0.0016 m/h to 0.14 m/h and the separation factors (S) are in range of 2.09 to 7.32 in the HCl/FeCl2 system at room temperature. The porous membrane structure and presence of amine functional group are responsible for the mechanism of diffusion dialysis (DD).

Oxygen Control Challenge for Advanced Wet Processing

A control of Dissolved Oxygen (DO) in liquids and oxygen concentration in ambient atmosphere for semiconductor processing is described. The effects of low DO in wet processing for galvanic corrosion and water mark formation were evaluated using various oxygen concentration conditions with HF or HCl mixtures. It was found that the low DO concentration condition (25ppb) prevented the occurrence of defects (voiding, trenching or water marks). The results from processing a device sample showed that low DO concentration condition is required for advanced CMOS processing.

Surface Chemistry of III-V Semiconductors After Wet Etching with HCl and H2O2

GaAs(100) was immersed in water and aqueous mixtures of isopropyl alcohol, ethylene glycol, acetic acid, glycolic acid, tartaric acid, and HCl with and without the addition of H2O2 to understand the etching mechanism. The surface composition after etching was characterized using x-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Ga and As oxides with high oxidation states dissolve in water, but acids are needed to remove the oxides with low oxidation states. H2O2 oxidized the bulk substrate, and only the acids that have pKa values lower than 4 supported etching. After etching with HCl, the surface is terminated by arsenic chloride (As-Cl).

Surface characteristics and bioactivation of sandblasted and acid-etched (SLA) Ti-10Nb-10Ta alloy for dental implant

Titanium and titanium alloys are amenable to processing as dental implant materials because of their low density, good mechanical properties, better biocompatibility, and excellent corrosion resistance. However, titanium-based implants cannot bond directly to bone. To induce osseointegration, numerous surface-treatment techniques have been investigated over the years to improve implant performance. In this study, we examine sandblasting and acid etching (SLA) methods to determine the various properties of SLA-treated Ti-10Nb-10Ta alloy. The SLA treatment included two steps: first, mechanically polished Ti-10Nb-10Ta alloy was subjected to grit blasting using 110-µm alumina particles, and second, the blasted alloy underwent acid etching for 9 minutes with a mixture of H2SO4 and HCl at 100°C. After etching with Keller’s etchant, the Ti-10Nb-10Ta alloy showed a lamellar structure on optical microscopy, and surface roughness was increased after SLA treatment (p<0.05). The apatite layer that formed on the SLA-treated Ti-10Nb-10Ta alloy after immersion in simulated body fluid was approximately 2 µm thick, thus improving adhesion to bone. Wettability of the SLA-treated Ti-10Nb-10Ta alloy was better than that of the non-treated one. In vitro studies showed no cytotoxicity from either the untreated or the SLA-treated Ti-10Nb-10Ta alloys.

Surface modification of fluorine-doped tin oxide films using electrochemical etching for dye-sensitized solar cells

We modified the surface of fluorine-doped tin oxide (FTO) films using electrochemical etching in order to improve the photovoltiac performance of dye-sensitized solar cells (DSSCs). For the electrochemical etching, a mixture of HCl and zinc precursor was used as the electrolyte, which generated the H+ needed for activating the SnO2 etching reaction. This led to the formation of surface-modified FTO films that resulted in an increase in surface roughness and a high level of haze without changing the sheet resistance and optical transmittance of the FTO films. The open circuit voltage, fill factor, and short-circuit current density of the DSSCs assembled using the surface-modified FTO films were 0.73V, 60.53%, and 15.67mA/cm2, respectively. The surface-modified FTO films created using electrochemical etching showed an improved photoconversion efficiency (~6.95%) when compared to bare FTO films (~6.33%). This improvement in performance was caused by an improved ability to trap light by increasing haze, which resulted in an enhancement in the surface roughness of the FTO films.

Thermal decomposition on Aceox® BTBPC mixed with hydrochloric acid

1,1-Bis(tert-butylperoxy)cyclohexane (BTBPC) has two active O–O peroxide groups and is usually used as an initiator in a chemical process. However, it also easily accelerates decomposition in the presence of certain catalysts. This paper discusses the runaway reactions of BTBPC alone or mixed with various concentrations of hydrochloric acid (HCl, 1.0, 2.0, 4.0, and 8.0 N). Essential thermokinetic parameters, including apparent exothermic onset temperature (To), peak temperature (Tp), apparent activation energy (Ea), heat of decomposition (∆Hd), and rate constant (k), were evaluated by differential scanning calorimetry under the heating rates of 1.0, 2.0, 4.0, and 8.0 °C min−1. A kinetics-based curve fitting method was employed to appraise the possible kinetic models and their thermokinetic parameters at 4.0 °C min−1 heating rate. All the BTBPC HCl mixtures have two exothermic peaks, but BTBPC alone and BTBPC mixed with 1.0 N HCl have just only one. 4.0 N HCl mixture has two endothermic peaks. To of the first peak in 8.0 N HCl mixtures is shifted to lower temperatures, 46.1 °C. The model of BTBPC is a single-stage reaction; however, BTBPC mixed with 1.0 or 2.0 N HCl is a two-stage decomposition reaction. Moreover, 4.0 or 8.0 N HCl mixture is three- and five-stage decomposition reaction, respectively. As more concentrated HCl is being mixed, kinetic models become more complex.

Surface Chemistry of III-V Semiconductors After Wet Etching with HCl and H2O2

The introduction of III-V semiconductors in MOSFET technology has been hindered by the lack of good quality III-V oxides. These oxides are a source of surface states at the band edges or within the band gap that are a detriment to electronic performance. The removal of these oxides is typically accomplished by immersion in acid or basic aqueous solutions. The continuous etching of the substrate is achieved by adding an oxidizing agent. After etching, a smooth oxide-free surface is desired. HCl and H2O2 mixtures have been used for the etching of III-V materials. In this work, we perform a comparative study of the etching of the (100) crystal plane of GaAs, InAs, InP, GaSb, and InSb. The selective etching of these materials was studied as a function of H2O2 concentration (0.0001-5 M) and at a fixed HCl concentration (0.01 M). The etching rate was determined by profilometry measurements made on wafers patterned with conventional photolithography. The chemical composition of the surfaces after etching was studied with X-ray photoelectron spectroscopy (XPS) and the final roughness was characterized with atomic force microscopy (AFM). The etching rate of GaAs and InAs (same group V atom) showed a volcano-shaped dependence on H2O2 concentration (0.01 to 1 M). A maximum etching rate was observed at 0.1 M with a value of 1.1±0.1 nm/s for GaAs and 0.9±0.3 nm/s for InAs. For 1 M H2O2, the etching rate decreased to 0.035±0.010 nm/s for GaAs and 0.26±0.13 nm/s for InAs. The etching rate of InP increased when the H2O2 concentration was changed from 0.01 to 0.1 M, and showed no significant increase for higher concentrations within the error of the measurements. The etching selectivity of GaAs to InP increased from about 55 at 0.01 M H2O2 to 137 at 0.1 M H2O2, and then decreased to 4 at 1 M H2O2. The etching rate of GaSb and InSb (same group V atom) increased linearly between 0.0001 and 0.001 M H2O2, but dropped significantly at higher concentrations. These substrates were visibly oxidized at high H2O2 concentrations and HCl etching was unable to keep up with the rate of oxidation. Substrates with the same group V atom exhibited similar etching trends in the range of H2O2 and HCl concentrations studied. This suggests that the removal of the group V atom is the rate limiting step in the etching of these materials. Temperature programmed desorption (TPD) of a GaAs sample after immersion in HCl showed that the surface was terminated by As-Cl bonds. These results along with the chemical composition of the samples after etching will be used to propose reaction mechanisms of III-V semiconductors in HCl and H2O2 mixtures.

Kinetics of heterogeneous decay of chlorine and hydrogen atoms in plasmas of HCl binary mixtures with Ar, H2, O2, and Cl2

The heterogeneous decay kinetics of chlorine and hydrogen atoms in plasmas of HCl mixtures with Ar, H2, O2, and Cl2 of variable initial composition have been studied using optical and spectral diagnostics methods and plasma simulation. It has been shown that the assumption about the constant recombination probability is inconsistent with the behavior of calculated concentrations of atoms depending on their reduced emission intensity. Mechanisms for the effect of the initial composition of the mixtures on the recombination probability have been proposed.

Use of Hydrofluoric Acid Desilicification in the Determination of Highly Siderophile Element Abundances and Re‐Pt‐Os Isotope Systematics in Mafic‐Ultramafic Rocks

Properly combining highly siderophile element (HSE: Re, Pd, Pt, Ru, Ir, Os) abundance data, obtained by isotope dilution, with corresponding 187Os/188Os and 186Os/188Os measurements of rocks requires efficient digestion of finely‐ground powders and complete spike‐sample equilibration. Yet, because of the nature of commonly used methods for separating Os from a rock matrix, hydrofluoric acid (HF) is typically not used in such digestions. Consequently, some silicates are not completely dissolved, and HSE residing within these silicates may not be fully accessed. Consistent with this, some recent studies of basaltic reference materials (RMs) have concluded that an HF‐desilicification procedure is required to fully access the HSE (Ishikawa et al. (2014) Chemical Geology, 384, 27–46; Li et al. (2015) Geostandards and Geoanalytical Research, 39, 17–30). Highly siderophile element abundance and Os isotope studies of intraplate basalts typically target samples with a range of MgO contents (&lt; 8 to &gt; 18% m/m, or as mass fractions, &lt; 8 to &gt; 18 g per 100 g), in contrast to the lower MgO mass fractions (&lt; 10 g per 100 g) of basalt and diabase RMs (i.e., BIR‐1, BHVO‐2, TDB‐1). To investigate the effect of HF‐desilicification on intraplate basalts, experiments were performed on finely ground Azores basalts (8.1–17 g per 100 g MgO) using a ‘standard acid digestion’ (2:1 mixture of concentrated HNO3 and HCl), and a standard acid digestion, followed by HF‐desilicification. No systematic trends in HSE abundances were observed between data obtained by standard acid digestion and HF‐desilicification. Desilicification procedures using HF do not improve liberation of the HSE from Azores basalts, or some RMs (e.g., WPR‐1). We conclude that HF‐desilicification procedures are useful for obtaining total HSE contents of some young lavas, but this type of procedure is not recommended for studies where Re‐Pt‐Os chronological information is desired. The collateral effect of a standard acid digestion to liberate Os, followed by HF‐desilicification to obtain Re and Pt abundances in samples, is that the measured Re/Os and Pt/Os may not correspond with measured 187Os/188Os or 186Os/188Os.

Fourth-derivative synchronous spectrofluorimetry and HPLC with fluorescence detection as two analytical techniques for the simultaneous determination of itopride and domperidone.

Two simple, rapid and sensitive methods, namely, fourth-derivative synchronous spectrofluorimetry (method I) and HPLC with fluorescence detection (method II) were developed for the simultaneous analysis of a binary mixture of itopride HCl (ITP) and domperidone (DOM) without prior separation. The first method was based on measuring the fourth derivative of the synchronous fluorescence spectra of the two drugs at Δλ = 40 nm in methanol. The different experimental parameters affecting the synchronous fluorescence of the studied drugs were carefully optimized. Chromatographic separation was performed in < 6.0 min using a RP C18 column (250 mm × 4.6 mm i.d., 5 µm particle size) with fluorescence detection at 344 nm after excitation at 285 nm. A mobile phase composed of a mixture of 0.02 M phosphate buffer with acetonitrile in a ratio of 55 : 45, pH 4.5, was used at a flow rate of 1 mL/min. Linearity ranges were found to be 0.1-2 µg/mL for ITP in both methods, whereas those for DOM were found to be 0.08-2 and 0.05-1.5 µg/mL in methods I and II, respectively. The proposed methods were successfully applied for the determination of the studied drugs in synthetic mixtures and laboratory-prepared tablets.

Microstructural evolution of ultrafine-grained NiCrCoAl foil after heat treatment at 1000°C

This research investigated the microstructural evolution of Ni–23·5Cr–2·66Co–1·44Al superalloy foil fabricated by electron-beam physical vapour deposition and annealed at 1000°C. The results showed that the deposited alloy mainly consisted of the γ-phase. After annealing at 1000°C, the peak moved to a lower 2θ degree on the deposited side and to a higher 2θ degree on the substrate side, which indicated that uniform strain existed at the deposited state and recovery occurred during annealing. With an increase in the annealing time, the (220) diffraction peak increased significantly. The average size of the grains increased and showed zigzag structures after being etched by a mixture of HNO3, HCl and HF etchant. After being annealed at 1000°C for 4 hours, the ultimate tensile strength of the Ni–23·5Cr–2·66Co–1·44Al superalloy foil was improved from 641 to 800 MPa.

ChemInform Abstract: A Novel Transition‐Metal‐Linked Hexaniobate Cluster with Photocatalytic H2 Evolution Activity.

AbstractThe new hexaniobate cluster K10 [(Nb6O19)CrIII(H2O)2] 2·28H2O is synthesized from an aqueous mixture of K7HNb6O19, CrCl3, en, and HCl (autoclave, pH 10.60—11.00, 160 °C, 5 d) followed by diffusion into a mixture of ethanol and water in the volume ratio of 1:2.5 (15% yield).

Effect of KNO3 to remove silver interferences in the determination of mercury(II): Application in milk and breast milk samples

Mercury determination was performed at rotating silver electrode (RSE) using square wave voltammetry (SWV) in electrolytic mixture of HCl (0.1molL−1) and KNO3 (0.2molL−1). The reproducibility, sensitivity and accuracy are good, provided the proper instrumental parameters and supporting electrolyte are used. The relationship between the peak current of mercury(II) and its concentration is linear with regression equation: I(μA)=0.784 [Hg(II)]+49.5 (r2=0.9878) in the dynamic range from 1.0×10−7 to 8.0×10−4molL−1. The detection limit (DL,3σ) and quantification limit (QL,10σ) were 4.61×10−8molL−1 and 15.3×10−8molL−1, respectively. The relative standard deviation (RSD) for seven replicate analysis of a solution containing 5.0×10−5molL−1 was 2.19%. Possible effects of Cu, Co, Fe, MnO4, Zn, were investigated but did not cause any significant interferences. Immobilization of mercury(II) on the surface of rotating silver electrode obeyed to the Langmuir adsorption isotherm. The calculated ΔG°ads value showed that the interaction between mercury and silver electrodes is mainly controlled by a chemisorption process. This methodology was potentially applied for mercury determination in milk and breast milk samples.

Bacterial cellulose nanocrystals: impact of the sulfate content on the interaction with xyloglucan

In the present work, bacterial cellulose nanocrystals (BCN) were prepared with three distinct sulfate contents, namely 0, 0.42 and 0.65 % OSO3−, by using HCl (BCN-HCl), a mixture of HCl and H2SO4 (BCN-HCl/H2SO4) and H2SO4 (BCN-H2SO4) as hydrolytic media, respectively. BCN were characterized by means of elemental analysis, X-ray diffraction, atomic force microscopy (AFM) and zeta potential measurements. All BCN samples had crystallinity indices of about 82 %, about 10 % higher than the original BC. The zeta potential values determined for BCN-HCl, BCN-HCl/H2SO4 and BCN-H2SO4 amounted to −(5 ± 1), −(40 ± 1) and −(46 ± 1) mV, respectively. The assembly between BCN-HCl, BCN-HCl/H2SO4 or BCN-H2SO4 and XG extracted from Tamarindus indica seeds was investigated by means of Freundlich isotherms, AFM, contact angle measurements, dynamic light scattering, ellipsometry and quartz crystal microbalance measurements. The adsorption experiments suggest that sulfate substitution on BCN surface as low as 0.65 % OSO3− impairs the original interaction with XG, thereby generating unstable layers with subsequent desorption. In contrast, the 0.42 % OSO3− samples presented favorable interactions with XG and exhibited highly improved colloidal stability compared to 0 % OSO3− samples. Films of XG adsorbed onto BCN with 0.42 % OSO3− were stable, homogeneous, and had low roughness and thickness. This is the first report showing that sulfate content on BCN surface can be tailored to promote high colloidal stability and sufficient interaction with XG.

High temperature (salt melt) corrosion tests with ceramic-coated steel

Thermal recycling of refuse in waste-to-energy plants reduces the problems connected to waste disposal, and is an alternative source of electric energy. However, the combustion process in waste incinerators results in a fast degradation of the steam-carrying superheater steel tubes by corrosive attack and abrasive wear. Higher firing temperatures are used to increase their efficiency but lead to higher corrosion rates. It is more economical to apply protective coatings on the superheater steel tubes than to replace the base material.In-situ tests were conducted in a waste-to-energy plant first in order to identify and quantify all involved corrosive elements. Laboratory scale experiments with salt melts were developed accordingly. The unprotected low-alloyed steel displayed substantial local corrosion. Corrosion was predominant along the grain boundaries of α-ferrite. The corrosion rate was further increased by FeCl3 and a mixture of HCL and FeCl3. Coatings based on pre-ceramic polymers with specific filler particles were engineered to protect superheater tubes. Tests proved their suitability to protect low-alloYed steel tubes from corrosive attack under conditions typical for superheaterS in waste incinerators, rendering higher firing temperatures in waste-to-energy plants possible.