Effect Of Hydrochloric Acid Research Articles

Removal of Cadmium(II) Ions from Chloride Solutions by Cyanex 301 and Cyanex 302

The main goal of this work was to study and compare the extraction of cadmium(II) ions by the two organophosphorous extractants: Cyanex 301 and Cyanex 302. The effect of different variables influencing the extraction of cadmium(II) ions such as the concentration of acid or metal ion and type of extractant has been investigated. Obtained results from the extraction process were compared with the FT-IR spectra. Results of spectrophotometric analysis confirm the observations of the extraction process, for example, the negative effect of hydrochloric acid on cadmium extraction by Cyanex 302.

Preparation of Conductive Fine Flake Expanded Graphite/Polyaniline Composites

Conductive fine flake expanded graphite/polyaniline composites was prepared by emulsion polymerization with sodium dodecyl benzene sulfonate(SDBS) as emulsifying agent, ammonium persulfate as initiator, hydrochloride and fine flakeexpanded graphite as dopants. Effects of hydrochloric acid, dopant, emulsifier and initiator to the conductivity has also been found through orthogonal experiment. The best condition, under which the conductivity is over 2.0S/cm, is 6% doped graphite, 6ml hydrochloric acid, 5.00g emulsifier and 3.25g initiator. It also demonstrates the improvement of the conductivity of polyaniline (PANI) via addition of graphite.

Effect of leaching concentration and time on the morphology of pores in porous glasses

Herein, porous glass was prepared by the acid leaching of phase-separated sodium borosilicate glass. The effects of hydrochloric acid (HCl) leaching concentrations varying from 0.1 to 3 M and of leaching times varying from 2 to 48 h on pore size and shape are reported here. The porous structure evolution was investigated through small angle X-rays scattering measurements and were compared to the classical nitrogen adsorption technique. We argue that the composition of these samples is not significantly modified with the acidic concentrations of the solution or with the leaching times tested. However, as expected a priori, we clearly show strong differences in porous structure. The investigation of different HCl leaching concentrations (from 0.1 to 3 M), with a small variation between each concentration, has enabled the observation of an interesting result. That is, we clearly show a non-linear effect of acidic concentration on the porous structure of these materials. At low acid concentrations, the specific area of these materials is relatively low. Increasing the HCl concentration to approximately 0.7 M leads to a strong increase in a specific BET area and total pore volume. However, further increasing of the acid concentration of the leaching solution leads to a decrease of both the specific surface area and the total pore volume. All of these results due to the presence of colloidal silica inside the pore structure can be explained by the well-known Zhdanov's model. These nanoparticles formed at an intermediate acid concentration seem to cluster when the acidity increases. The effect of the leaching time is less significant than the HCl concentration; however, this same assumption can be explained by the experimental results.

Pyrolytic carbons from acid/base-treated rice husk as lithium-insertion anode materials

The effects of hydrochloric acid and sodium hydroxide as leachants on the lithium-insertion properties of pyrolytic carbons prepared from rice husk are presented. All the disordered carbonaceous products had interlayer spacings (d002) of more than 3.7 Å, with values decreasing with an increase in the concentration of the leachant. The values of the H/C ratio and the R-parameter, the reciprocal of which is a measure of the number of non-parallel single layers of carbon, also diminished with an increase in the concentration of NaOH. An increase in the alkali concentration was found to improve the porosity of the carbons, as evidenced by the Brunauer–Emmett–Teller (BET) surface area data. An interaction of these factors determines the observed capacities of the carbon products. The highest insertion and deinsertion capacities were observed with the carbon obtained from rice husk treated with 0.3 M NaOH, the values being 819 and 463 mAh/g, respectively.

Effect of hydrochloric acid on the transport properties of tin through ion-exchange membranes

This work presents a study of the transport properties of two ion-exchange membranes present in an electrochemical reactor used to process the wasted and rinse baths of the electroless plating of polymers industry. The influence of the hydrochloric acid on the transport properties of tin through both cation- and anion-exchange membranes has been evaluated by chronopotentiometry. The shape of the chrono-potentiograms depends on the specie under consideration, Sn(II) or Sn(IV), the hydrochloric acid concentration and the type of membrane. In the case of the study of Sn(II) transfer through the cation-exchange membrane (CEM), the contribution of the water splitting is evident for every HCl concentration by the increase of the membrane potential drop (Em) after a short-time plateau observed in the chronopotentiograms, and by the appearance of a Sn(OH)2 precipitate located at the anodic solution-membrane interface. The transport of Sn(IV) through the CEM is a complex phenomenon due to their high charge density leading to an important hydration shell, to their low mobility and, to their trend to form hydroxyl complexes and insoluble salts. Low HCl concentrations and high applied currents leads to the formation of a Sn(IV) specie, probably the Sn(OH)62- monomer, which can polymerise and remain adhered to the membrane surface. This specie is re-dissolved when the HCl concentration is increased. In the case of Sn(II) transfer through the anion-exchange membrane (AEM), if the applied current is high and the HCl concentration is low, the OH- produced due to water splitting are forced to cross the membrane when the chloride concentration in solution is depleted. For higher HCl concentration, the development of the gravitational convention phenomenon is coupled with the water splitting at those high applied currents. The presence of Sn(IV) at low HCl concentration in the over-limiting region produces a diffusion-relaxation region characteristic of the bipolar membranes. The formation of a Sn(IV) gelatinous specie adhered to the anodic side of the AEM could explain the formation of the bipolar structure in the membrane. At lower pH values the formation of this Sn(IV) gelatinous specie is avoided, and the OH- ions from the water splitting are responsible for the peak of Em observed in the chronopotentiograms.

The effect of acids on dipalmitoyl phosphatidylcholine (DPPC) monolayers and liposomes

Dipalmitoyl phosphatidylcholine (DPPC) is the most abundant phospholipid in lung surfactant, primarily responsible for the reduction of surface tension to near 0 mN/m during expiration. In addition, DPPC liposomes are also used for drug delivery. In this study, the effects of hydrochloric acid, nitric acid and sulphuric acid on various properties of DPPC was investigated. The surface pressure versus area isotherms of DPPC monolayers at different concentrations of acid were obtained using a Langmuir–Blodgett trough. Distinct changes in the shapes of DPPC isotherms were observed in presence of acid. The lift off area for DPPC control at pH 7.4 was 58 Å 2. The lift off area for DPPC was 105, 100 and 95 Å 2 at concentration of 15.5 × 10 −2 mol/dm 3 of nitric acid, sulphuric acid and hydrochloric acid respectively. Collapse plateaus were longest in presence of nitric acid compared to hydrochloric acid and sulphuric acid. The nitric acid treated liposomes showed improved adsorption as evidenced by lower surface tension values achieved within 1 s at concentrations ranging from 3.1 × 10 −6 to 15.5 × 10 −4 mol/dm 3 having pH 6.2–2.9. The inhibitory concentrations of nitric acid which significantly increased the average surface tension values achieved within 1 s were 3.1 × 10 −3 to 15.5 × 10 −2 mol/dm 3 (pH 2.6–1.0). The sulphuric acid treated liposomes showed improved adsorption at concentrations of 3.1 × 10 −6 to 3.1 × 10 −2 mol/dm 3 (pH 6.1–1.7). The adsorption was significantly inhibited at pH 1.4–0.4 achieved with sulphuric acid. The HCl-treated liposomes showed an improved adsorption at concentrations ranging from 3.1 × 10 −6 to 15.5 × 10 −2 mol/dm 3 (pH 6.4–1.3). The average surface pressure value achieved within 1 s at inhibitory concentration of 3.1 × 10 −1 mol/dm 3 of HCl at a pH of 0.83 was 10.1 ± 2.2 mN/m. Acids did not affect the compressibility of DPPC. Increased leakage of calcein from DPPC liposomes at decreasing pH suggested increased permeability of DPPC liposomes under acidic conditions. The results of this study may have implications for pH dependent drug delivery in acidic conditions as well as for lung surfactant dysfunction in acid lung injury.

Optimised treatment of Palm Oil Mill Effluent

In this paper, we study experimentally the problem of separating oil from the oil?water emulsion that emulates Palm Oil Mills Effluent (POME). The investigations are focused on the effects of hydrochloric acid (HCl) and treatment conditions, e.g., operating temperature and magnetic stirring, on the separation process. The experiment results reveal that a higher flotation rate of oil is achieved after being treated using HCl. Similarly, the elevated operating temperature of the treatment enhances the oil separation from the emulsion. The introduction of magnet would produce higher rate of flotation than that of without magnet even in the absence of stirring.

ChemInform Abstract: Effect of Hydrochloric Acid on the Reductive Amination of 1‐(3‐Nitropyridin‐2‐yl)pyridinium Salts.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Enhancement of basic dye adsorption uptake from aqueous solutions using chemically modified oil palm shell activated carbon

The effect of hydrochloric acid (HCl) treatment of activated carbon prepared from oil palm shell on methylene blue (MB) adsorption was investigated. The Fourier transform infrared spectroscopy (FTIR) measurements showed that the surface chemistry of the activated carbon was influenced by the acidic treatment. Adsorption equilibrium data were fitted to the Langmuir, Freundlich and Dubinin–Radushkevich isotherm models. The equilibrium data for both the untreated and HCl-treated activated carbons were best represented by the Langmuir isotherm. The adsorption capacity of HCl-treated activated carbon was 303.03 mg/g, which was 24.24% higher compared to the untreated activated carbon. The kinetic data were found to follow closely the pseudo-second-order model for both activated carbons. Various thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°) and standard free energy (ΔG°) were evaluated. The adsorption of MB on the HCl-treated activated carbon was found to be endothermic in nature and was favoured by using a higher solution pH.

Effect of hydrochloric acid on pickling of hot-rolled 304 stainless steel in iron chloride-based electrolytes

Weight loss, corrosion potential and EIS measurements were performed to understand the role of HCl in the pickling of oxidised 304 stainless steel in iron chloride-based electrolytes. The surface finish was analysed with SEM–EDX. The oxidised 304 stainless steel is active on immersion, resulting in a low corrosion potential and a high weight loss. After certain duration the stainless steel either remains active or becomes passive depending on HCl content. At low HCl contents, an ongoing active-to-passive transition results in localised corrosion at pits, grain boundaries and honeycombed recesses. The corrosion potential becomes high and the weight loss is suppressed. The weight loss decreases in the initial stage and rises on extended pickling with adding HCl. Because of anodic brightening, the 304 stainless steel is always active as HCl is concentrated. In contrast with the material that is passivated, the charge transfer resistance is considerably low and the double layer capacitance is large during that brightening.

Effect of electrolytes on the sensitivity of thermal-lens measurements in aqueous media

The thermooptical properties of aqueous solutions of strong electrolytes (H2SO4, HCl, NaCl, Na2SO4, and NaOH) are considered. The thermal lens signal depends on the nature of the electrolyte. The effect of an electrolyte is not the sum of the effects of the constituent ions. The largest gain in the sensitivity of thermal-lens measurements is achieved with sulfuric acid (sensitivity enhancement factor of 2 for 0.6 M H2SO4 versus water) and sodium chloride (sensitivity enhancement factor of 1.5 for 3 M NaCl), while the effect of hydrochloric acid is negligible.

Effect of hydrochloric acid on the reductive amination of 1-(3-nitropyridin-2-yl)pyridinium salts

Effect of hydrochloric acid on the reductive amination of 1-(3-nitropyridin-2-yl)pyridinium salts

Study on superabsorbent composite. VIII. Effects of acid‐ and heat‐activated attapulgite on water absorbency of polyacrylamide/attapulgite

AbstractA novel superabsorbent composite, polyacrylamide/attapulgite, from acrylamide (AM) and attapulgite (APT), was prepared by free‐radical polymerization, using N,N′‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator. The effects of hydrochloric acid (HCl) concentration, acidification time, and acidification temperature while acidifying APT and temperature and APT heat‐activation on water absorbency of the superabsorbent composite in distilled water and in 0.9 wt % NaCl solution were studied. The water absorbency first decreases with increasing the HCl concentration while acidifying APT, and then increases with further increasing the HCl concentration. Prolongation of acidification time is of benefit to the increase of water absorbency. At a given HCl concentration, water absorbency for the composite increases with increasing acidification temperature. An important increase in water absorbency was observed after incorporating heat‐activated APT into the polymeric network, reaching a maximum of 1964 g g−1 with the APT heat‐activated at 400°C. Acid‐ and heat‐activation can influence chemical composition, crystalline structure, cation exchange capacity (CEC), and specific surface area of APT according XRF, XRD, FTIR analysis, and physicochemical properties test, and then on water absorbency of corresponding PAM/APT superabsorbent composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2419–2424, 2007

Oxidative Chemical Polymerization of P-Sulphanilamide and Characterization of the Polymer Obtained

ABSTRACT The oxidative chemical polymerization of p-sulphanilamide was studied in hydrochloric acid solution using sodium dichromate as oxidant at 5°C under nitrogen atmosphere. The effect of hydrochloric acid, sodium dichromate, and monomer concentration on the polymerization reaction was investigated. The orders of the polymerization reactions with respect to hydrochloric acid, sodium dichromate, and monomer concentrations are found to be 0.73, 0.971, and 0.966, respectively. Also, the effect of temperature on the polymerization rate was studied and the apparent activation energy was calculated and its value was found to be 24.291 × 104 J/mol. The characterization of the obtained polymer sample at the optimum conditions was carried out by IR, UV-visible, 1H-NMR, 13C-NMR, X-ray diffraction, electron microscopic, and thermogravimetric analysis. The dielectric and a.c. conductivity were investigated as a function of temperature.

Production of Ceramic Pigments Based on Natural Wollastonite Using the Gel Method

The authors consider the possibility of producing ceramic pigments based on natural wollastonite using the gel method, which contributes to the formation of an amorphous structure in wollastonite under the effect of hydrochloric acid. The chromophores are soluble salts containing Fe3+, Ni2+, Cr3+, Cu2+, and Co2+ ions. The wollastonite structure is restored under firing; the color characteristics of pigments after the gel-formation stage improve. The use of the gel method does not require a cardinal modification of the technological scheme and equipment but facilitates a significant improvement of the color properties of pigments and paints.

Correlation of gastric mucosal damage with sialic acid profile in rats: effect of hydrochloric acid, pepsin and hypertonic saline

Sialic acids occupy terminal positions on gastric mucus glycoprotein where they contribute to the high viscosity of mucin. Desialylation of mucus may lead to degradation of the mucus and eventually to the breakdown of the gastric mucus barrier. The effect of a variety of damaging agents (0.1 M HCl, 2 mg ml(-1) pepsin and 2 M NaCl) on sialic acid profile was determined in pylorus-ligated rats. The relationship between sialic acid, galactose, pyruvate and the extent of gastric mucosal damage were studied. Instillation of pepsin significantly increased total sialic acid, galactose and macroscopic mucosal lesions in the stomach. Instillation of 0.1 M HCl reduced the total sialic acid but this decrease was not significant. Acidity led to a significant increase in the amount of free sialic acid in the gastric instillates and the macroscopic lesions induced by acid was not significantly different from the control animals (0.15 M NaCl). 2 M NaCl induced the macroscopic lesions in the stomach and also free sialic acid in the instillates. Pepsin potentiates the action of 2 M NaCl. In all the agents examined with the exception of acid, it was observed that an increase in free sialic acid and galactose was accompanied by gastric mucosal erosion and elevation of pyruvate concentration. It is concluded that gastric acidity alone is not inherently damaging and that resistance of gastric mucosa to destructive agents may be dependent on the integrity of the sialic acids.

AQUEOUS OXIDATIVE CHEMICAL POLYMERIZATION OF N-METHYLANILINE IN ACID MEDIUM AND CHARACTERIZATION OF THE OBTAINED POLYMER

The oxidative chemical polymerization of N-methylaniline was studied in hydrochloric acid solution using sodium dichromate as oxidant at 5°C under nitrogen atmosphere. The effect of hydrochloric acid, sodium dichromate and monomer concentration on the polymerization reaction was investigated. The order of reaction with respect to hydrochloric acid, sodium dichromate and monomer concentration was 0.816, 0.735 and −0.83 respectively. Also, the effect of temperature on the polymerization rate was studied and the apparent activation energy of this polymerization reaction was found to be 1.999×104 J/mol. The characterization of the obtained polymer sample at the optimum conditions was carried out by IR, UV-visible, 1H-NMR, X-ray diffraction, electron microscope and thermogravimetric analysis. The ac conductivity of the obtained polymer samples was measured and the highest values were found for the samples prepared at hydrochloric acid, sodium dichromate and monomer concentrations of 0.200, 0.0094 and 0.1869 mol/L respectively at 5°C.

Effect of Hydrochloric Acid on the Proliferation of Tetraploid Meth-A Cells

Effect of Hydrochloric Acid on the Proliferation of Tetraploid Meth-A Cells

EQUILIBRIUM OF PALLADIUM(II) EXTRACTION WITH 1-OCTYLTHEOBROMINE

ABSTRACT 1-Octyltheobromine was synthesized to study extraction equiliburium of palladium(II). To evaluate its efficiency as an extractant, the extraction of palladium(II) from acidic chloride media was studied at 303K using toluene. The extraction of palladium(II) from hydrochloric acid media by 1-octyltheobromine exhibited high selectivity for palladium(II) over the platinum group metals. The stoichiometrics of the extraction of palladium(II) with 1-octyltheobromine was elucidated by examining the effects of hydrochloric acid, chloride ion, hydrogen ion, extractant and metal ion concentrations on its extractability. Palladium(II) was found to be extracted as two molecules of 1-octyltheobromine reacted with PdCl2 as follows: PdCl2 +{2}¯RN ⟺ ¯PdCl2(RN)2. The extraction equilibrium constant was K=2.72 × 108(mol dm−3)−2. The complex of 1-octyltheobromine with PdCl2 was confirmed by mass spectrometric analysis. The stripping of palladium(II) was performed over 60% by a single batchwise treatment with an aqueous solution of thiourea or ammonia.

Simultaneous determination of seven impurities in high-purity cobalt oxide by ICP-AES after matrix separation using 1-nitroso-2-naphthol as a precipitant

A method was developed for the simultaneous determination of seven trace impurities (Cd, Mn, Pb, Zn, Cu, Fe and Ni) in high-purity cobalt oxide by ICP-AES. The matrix effect was eliminated by precipitation with 1-nitroso-2-naphthol. The matrix effect of cobalt on the absorptions of trace impurities, the effects of reaction time, pH value, dosage of precipitant on the formation of cobalt-1-nitroso-2-naphthol complex, the effects of hydrochloric acid on the stability of this complex and masking of elements were studied. Recoveries of the impurities in spiked sample are from 90% to 110% with a precision of 1.1%–5.0% RSD. The detection limits of the seven elements are in the range of 0.01–0.24µg/g. The method can be applied to the analysis of high-purity cobalt metal, cobalt oxide and other cobalt compounds.