Addition Of Tartaric Acid Research Articles

Formation of protective anodic oxides on aluminium by low voltage anodising in sulphuric acid with cerium nitrate and tartaric acid additions

The effects of the anodising potential and of the combined addition of tartaric acid and cerium nitrate to a sulphuric acid anodising bath on the corrosion behaviour of high purity aluminium and on AA2024T3 aerospace aluminium alloy have been systematically investigated. It is found that the anodising potential is critical in determining the anticorrosion performance; lower potential generates finer pores that provide enhanced corrosion protection compared with the larger pores generated at higher potentials. At both anodising potentials, the addition of cerium nitrate alone to the sulphuric acid bath does not increase significantly the anticorrosion performance. Conversely, the addition of tartaric acid alone is generally beneficial. Finally, when cerium nitrate is added in combination with tartaric acid a further improvement of the corrosion resistance is observed.

Formation and regulation of supramolecular chirality in organogel via addition of tartaric acid

A new 1,8-naphthalimide derivative was prepared in which the C-4 position was substituted by pyridin-4-ol. This derivative shows good gelation property that can gelate most of polar solvents. As an achiral molecule, helical fibre morphology was observed when the compound gelated acetone solvent. When 0.5 eq of D-tartaric acid or L-tartaric acid was added to the gel, the helical morphology was changed from left-handed to right-handed structure. This result was further proved by circular dichroism measurement. FT-IR experiment showed the formation of intermolecular H-bond between the gelator and tartaric acid. The photophysical properties of gelator had no difference before and after addition of tartaric acid; whereas the lamellar structure was varied by addition of tartaric acid.

Synthesis and Electrochemical Behaviour of LiMn<sub>(2-x)</sub>Zn<sub>x</sub>O<sub>4</sub> Cathode Materials

Lithium manganese oxide, LiMn2O4, is said to be the most promising cathode material to replace the present day ones used in commercial Li-ion batteries. However, it suffers from capacity fading. One of the ways to improve this material is by substituting some of the Mn atoms with some other metal or transition metal element to stabilize the material. Spinel type lithium manganese zinc oxide, LiMn(2-x)Zn\xO4 (x= 0.1, 0.2, 0.3, 0.4, 0.5) were prepared by sol-gel method. The compounds have a potential to improve pure LiMn2O4 performance. This method involves the mixing of acetates of metals and dissolved in absolute ethanol followed by the addition of tartaric acid. Tartaric acid acts as a gelling agent of the metal complexes and the compound was dried at low temperature to obtain the precursor of LiMn(2-x)ZnxO4. The synthesized product was annealed at a temperature of 850 oC for about 24 hour and X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were done. Battery fabrications using the cathode materials were done using a non-aqueous electrolyte and Li metal as the anode. From charge-discharge studies, it was found that LiMn1.9Zn0.1O4 has better discharge capacity.

Tin content determination in canned fruits and vegetables by hydride generation inductively coupled plasma optical emission spectrometry.

Tin content in samples of canned fruits and vegetables was determined by hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-OES), and it was compared with results obtained by standard method of flame atomic absorption spectrometry (AAS). Selected tin emission lines intensity was measured in prepared samples after addition of tartaric acid and followed by hydride generation with sodium borohydride solution. The most favorable line at 189.991 nm showed the best detection limit (1.9 μg L−1) and limit of quantification (6.4 μg kg−1). Good linearity and sensitivity were established from time resolved analysis and calibration tests. Analytical accuracy of 98–102% was obtained by recovery study of spiked samples. Method of standard addition was applied for tin determination in samples from fully protected tinplate. Tin presence at low-concentration range was successfully determined. It was shown that tenth times less concentrations of Sn were present in protected cans than in nonprotected or partially protected tinplate.

Large-scale synthesis of Li1.15V3O8 nanobelts and their lithium storage behavior studied by in situ X-ray diffraction

Li1.15V3O8 nanobelts with length 3 μm, width 200 nm and 20–50 nm in thickness are prepared on a large scale by a tartaric acid-assisted sol–gel technique. They show greater reversibility of the lithium ion insertion/extraction reaction than those synthesized without the addition of tartaric acid. After twenty cycles, the reversible lithium storage capacities of Li1.15V3O8 prepared from tartaric acid assisted and free techniques are 231.0 and 194.5 mAh/g at a current density of 30 mA g−1, respectively. Cycled at 20 mA g−1 in 1.5–4.1 V, Li1.15V3O8 nanobelts can deliver discharge and charge capacities of 297.0 and 298.4 mAh/g, respectively. Increasing the charge/discharge current density to 2400 mA g−1, the lithiation and delithiation capacities of Li1.15V3O8 nanobelts can be mantianed at 184.2 and 184.2 mAh/g, respectively. In situXRD observation reveals that the host structure of Li1.15V3O8 nanobelts will not be destroyed with a discharge process to 0.0 V at 20 mA g−1 or a short circuit for 24 h. Over-lithiation can induce the formation of an inactive compound, leading to poor electrochemical properties of Li1.15V3O8 nanobelts. The first lithiation/delithiation process in 0.0–4.1 V or 1.5–4.1 V is a reversible reaction at a current density of 60 mA g−1, and is composed of reversible single-phase structural evolutions in a high voltage region and two-phase structural transitions in a low voltage region. The electrochemical properties of Li1.15V3O8 nanobelts are poorer at the 10th cycle in 0.0–4.1 V than that obtained in 1.5–4.1 V. In situXRD results indicate that the breakdown of two-phase transition in a low voltage region is the main factor for poor cycleability. Besides, a delay of structural evolution and asymmetry lithiation/delithiation process can be observed at high rates, which may also be responsible for the deterioration of cycleability of Li1.15V3O8 nanobelts.

Antilisterial Activity and Consumer Acceptance of Irradiated Chicken Breast Meat Vacuum‐Infused with Grape Seed and Green Tea Extracts and Tartaric Acid

Contamination of poultry with pathogenic bacteria contributes to human foodborne disease, causes damage to industry brand names, and has a significant economic impact on the food industry in the form of both damage to industry brand names and losses associated with recalls. Irradiation is a safe and effective means of decontaminating poultry products, but the maximum dose strengths allowed negatively impact poultry sensory quality characteristics. The 1st objective of this study was to investigate the potential interactive inhibitory effects of natural antimicrobials as components of a vacuum-marination in addition to various dose levels of irradiation. Tartaric acid (TA) at 2 levels and grape seed (GS) and green tea (GT) extracts were combined, vacuum-infused into chicken breast fillets, and irradiated at 1, 2, and 3 kGy by electron beam irradiation. The 2nd objective was to use a consumer test group to evaluate TA and plant extract infusion into chicken breast fillets with and without irradiation at 2 kGy on overall impression, flavor, texture, appearance, and tenderness. The results showed that samples vacuum-infused with TA at 37.5 and 75.0 mM and irradiated at 1 kGy significantly reduced Listeria monocytogenes (L.m.) levels by 2 and 3 log CFU/g compared to the control after 12 d of refrigerated storage. Vacuum-infusion of TA at 37.5 and 75.0 mM at 2 and 3 kGy irradiation, reduced L.m. to near nondetectable levels. The addition of TA and GS and GT to chicken breast fillets with and without irradiation did not significantly impact consumer preference, tenderness, appearance, or flavor. The addition of tartaric acid and natural plant extracts to chicken marinades could contribute to the prevention of L.m. contamination.

Role of Tartaric Acid on the Anodizing and Corrosion Behavior of AA 2024 T3 Aluminum Alloy

Tartaric acid is added to sulfuric acid anodizing baths to generate porous anodic film that provides corrosion resistance to practical aerospace alloys and reduces the environmental impact of the traditional chromic acid anodizing process. Here, a fundamental study on the effects of the addition of tartaric acid to the sulfuric acid anodizing electrolyte has been undertaken. During anodizing, it was evident that tartaric acid does not significantly affect the mechanism of porous film growth, but it reduces the growth rate of the porous anodic film. After anodizing, in acidic environments, it may reduce the dissolution rate of a previously formed oxide. Furthermore, it was found that in a nearly neutral, chloride-rich environment, tartaric acid limits the anodic reaction of aluminum dissolution at concentrations in the hundreds of ppm range. The previous suggests that the good anticorrosion performance of alloys anodized in the presence of tartaric acid is due to residues of tartaric acid in the pore solution.

Graded Anodic Films for Corrosion Protection of Aerospace Alloys: Anodizing Procedure and Corrosion Behaviour

The presence of alloying elements such as copper, magnesium and zinc in the 2xxx and 7xxx aluminium alloys increases mechanical properties but requires specific anticorrosion measures such as anodizing followed by painting. In this work, the performance of the anodic film was initially examined showing that, for a fixed anodizing electrolyte, a finer porous film morphology, generated at reduced potentials, provides better corrosion resistance than a coarser morphology generated at increased potentials. Complementing the previous, the effects of addition of tartaric acid to the anodizing electrolyte were examined, showing that tartaric acid does not affect significantly the porous film growth, but it reduces the dissolution rate of a previously formed oxide. Further, it was demonstrated that tartaric acid acts as an anodic inhibitor at concentrations in the ppm range, suggesting that the contributions to the anticorrosion performance are due to residues of tartaric acid in the pore solution.

FESEM and EIS Study of Sealed AA2024 T3 Anodized in Sulfuric Acid Electrolytes: Influence of Tartaric Acid

The present study investigates the effect of tartaric acid on anodic film morphology and on corrosion resistance of hydrothermally sealed anodized AA2024. Anodizing treatment was performed in dilute sulfuric acid electrolyte with or without addition of tartaric acid. Hydrothermal sealing was carried out in boiling water for each anodized specimen. The morphology of the sealed anodic films was examined using field-emission scanning electron microscopy (FESEM). Electrochemical impedance spectroscopy (EIS) was performed to assess sealing quality and corrosion resistance of the anodic films. It was shown that the sealing was more efficient in the case of anodic films formed in tartaric acid electrolyte mainly due to their lower porosity. It was also observed that the properties of the barrier layer were higher when sealing was performed on specimens anodized in the presence of tartaric acid. This suggests a specific role of the species on the barrier layer, which contributes to the enhancement of the performance in terms of corrosion resistance of the sealed anodic films. The present study clearly validates the beneficial role of tartaric acid in anodizing baths for the corrosion protection of AA2024.

The fabrication and thermal expansion properties of 4H-Ag nanowire arrays in porousanodic alumina templates

Hexagonal silver nanowire (4H-Ag NW) arrays with preferred orientation arefabricated into the holes of porous anodic alumina membranes (AAMs) by directcurrent electrodeposition. The addition of tartaric acid and low depositiontemperature are crucial conditions for the growth of 4H-Ag NWs. The thermalexpansion properties of the as-prepared and annealed 4H-Ag NWs are studied byin situ x-ray diffraction in the temperature range from room temperature to800 °C. The axial thermal expansion coefficient (TEC) of the as-prepared sample decreasesinitially and increases subsequently, while that of the annealed sample consistentlyincreases during the whole measuring process.

Sol–gel technology as representative processing for nanomaterials: case studies on the starting solution

In order to fabricate sol–gel products with desired microstructure in the form of bulk, fiber and coating film, the appropriate selection of the composition of the starting solution is of primary importance. In this paper, the effects of the composition of the starting solution on the reaction in alkoxysilane solutions, the formation of bulk and fiber, and the microstructure of a particular coating film are reviewed, based on our experiences. It is shown in the alkoxysilane and alkylalkoxysilane solutions that, besides hydrolysis and random polymerization, various reactions take place. Among them, the formation of a four-membered ring molecule in dimethyldialkoxysilane solution, formation of a cage-like cubic octamer in an tetraalkoxysilane solution containing, for example, tetramethylammonium ion and stabilization of a solution for polycomponent oxides by the addition of tartaric acid are discussed. It is also shown that the composition of the starting solution suitable for fiber drawing is different from that for the formation of crack-free bulk gels: for the fiber drawing acid catalyst and low water content are required in various oxide systems including silica, while for the bulk silica gels ammonia-catalyzed alkoxysilane solution with dimethylformamide solvent or highly acidic solution works well for bulk silica gel. Finally, it is shown that the control of microstructure of coating films can be realized by selecting the composition of the starting solution. As an example, the change of the acid content of the starting solution produces three different microstructures of polycrystalline, crystal-oriented and amorphous structure in the lithium borate coating film. As another example, the size of precipitated noble metal particles in the coating film is controlled by the water and acid content of the solution. The mechanism of the above phenomena is also discussed.

In VitroBioavailability of Iron and Sensory Qualities of Iron-Fortified Wheat Biscuits

Because biscuits are a popular snack item and are consumed frequently by the younger population, fortification of biscuits with iron can be beneficial in preventing iron-deficiency anemia, which is widely prevalent in developing countries. To determine the bioavailability of iron from biscuits fortified with either ferrous sulfate or sodium iron ethylenediaminetetraacetic acid (NaFeEDTA) equivalent to 8.8 mg of iron per 100 g of flour in combination with either citric and tartaric acids at 60, 80, or 100 mg/100 g levels. The study involved analysis of physical characteristics, total and ionizable iron of biscuits, and sensory qualities. The ionizable iron value was used to calculate bioavailable iron. The biscuits were evaluated for sensory attributes by 30 panelists with the help of a scorecard specially developed for biscuits. The amount of bioavailable iron in biscuits increased over that in controls by about 27% after the addition of ferrous sulfate and 83.8% after the addition of NaFeEDTA. The addition of citric acid (80 mg/100 g) along with ferrous sulfate increased bioavailability by about 104% over that in controls. The maximum increase was seen on addition of tartaric acid (100 mg/100g). The amount of bioavailable iron increased by 117% after the addition of NaFeEDTA with 80 mg/100 g of citric acid and by 338% after the addition of NaFeEDTA with 100 mg/100 g of tartaric acid. Sensory evaluation tests indicated that NaFeEDTA-fortified biscuits were more acceptable than ferrous sulfate-fortified biscuits and that biscuits fortified with NaFeEDTA along with tartaric acid were similar to control biscuits in all sensory attributes. From both the subjective and the objective evaluation of biscuits, it can be concluded that the addition of NaFeEDTA along with either citric acid (80 mg/100 g) or tartaric acid (100 mg/100 g) results in improved iron bioavailability with an organoleptically acceptable product.

Cyclic oxidation processes during anodizing of Al–Cu alloys

The influence of copper on the morphologies of porous anodic alumina has been investigated under current and voltage control using a sputtering-deposited Al–2.7 at.% Cu alloy and a commercial AA 2024-T3 aluminium alloy anodized in either sulphuric acid electrolyte or the same electrolyte but with addition of tartaric acid. The findings indicate that film development involves repeated formation of embryo cells of anodic alumina at the metal/film interface. During the initial stages of anodizing at constant voltage, cell formation is accompanied by current peaks in the current–time response. The porosity of the resultant films has a lateral aspect due to the layering of embryo cells. The thickness of individual layers is proportional to the formation voltage, with a ratio of the order 1 nm V−1. The cell formation is accompanied by enrichment of copper in the alloy, incorporation of copper species into the anodic film, in low amounts relative to the alloy, and evolution of oxygen. These processes disrupt the formation of the classical pore morphology, characteristic of high purity aluminium, due to continuous formation of fresh embryo cells and re-direction of pores. The main effect of the tartaric acid addition to the sulphuric acid was to reduce the rate of anodizing of the alloys at constant voltage by about 10–20%.

Quantitative analysis of Nb in solution in a microalloyed carburizing steel by electrochemical etching

The amount of Nb in solution in a microalloyed carburizing steel (Nb-modified SAE 8620) was evaluated in different heat treated conditions. The test procedure involved electrochemical extraction, filtration and Inductively Coupled Plasma Atomic Emission Spectroscopic (ICP-AES) analysis. Characterization by X-ray diffraction of the residues collected in the filters was also performed. Results showed that Nb in solution tends to hydrolyze during electrolysis in a 10 vol.% HCl electrolyte, giving misleading measurements of the amount of Nb that dissolved during high temperature heat treatment. Hydrolysis of Nb is prevented by the addition of tartaric acid to the electrolyte. In the full dissolution condition, coarse (Ti,Nb)CN was the only precipitate present. Finer (Nb,Ti)C precipitates were observed after heat treating at 1050 °C.

Interaction between Cr(VI) and a Fe-rich soil in the presence of oxalic and tartaric acids

This study examined the interaction between Cr(VI) and a Fe-rich soil in the presence of low-molecular-weight organic acids as a function of pH. Oxalic and tartaric acids were chosen since they existed in soils commonly. Batch experiments showed that adsorption of Cr(VI) by the soil within the pH range examined was inhibited in the presence of oxalic acid, which was more pronounced when the initial ratio of [oxalic acid]/[Cr(VI)] was raised from 1:1 to 2:1. With the addition of tartaric acid, concentration of Cr(VI) in equilibrium solutions was far less than that of single adsorbate system across the pH wide (2.5–5.5), which was noticeable especially at low pH. The results were attributed to Cr(VI) adsorption and, particularly, the soil surface catalyzed reduction of Cr(VI) to Cr(III) by tartaric acid. The data reported in this paper suggested that the mobility, the bioavailability, and the toxicity of Cr(VI) in soil environments might be greatly affected by pH, the presence and nature of low-weight-molecular organic acids (oxalic and tartaric acids).

Preparation of Cu/SiO2 catalysts with and without tartaric acid as template via a sol–gel process

Abstract Cu/SiO2 catalysts were prepared via a sol–gel process in the presence and absence of a hydroxy-carboxylic acid (tartaric acid) as a non-surfactant template or pore-forming agent. These catalysts were characterized by means of nitrogen sorption, X-ray diffraction, Fourier transformed infrared spectrometry, thermal gravimetric analysis, temperature programmed reduction, N2O dissociative chemisorption, and transmission electron microscopy. They were evaluated in the partial oxidation of methanol (POM). The addition of tartaric acid showed two major and opposite effects on the final catalyst. On the one hand, tartaric acid has the ability to increase the pore size and specific surface area generating a mesoporous material without long-range ordering channel arrangements. On the other hand, the presence of tartaric acid contributes to decreasing the copper dispersion by aggregation of Cu species. The catalyst prepared in the presence of TA was much more active in POM than that prepared in the absence of TA. However, the last one showed a higher yield to hydrogen ( Y H 2 ≈ 49 % ) with a very good selectivity ( S H 2 ≈ 99 % ) .

Agglomeration characteristic of particles in alumina slurry by addition of chemicals and milling process for Cu CMP

Chemical mechanical polishing (CMP) has been widely accepted for the global planarization of multi-layer structures in semiconductor manufacturing. It is generally known that the implementation of optimum slurry composition is one of the important issues. In this experiment, we observed and analyzed the variation by the addition of chemicals and milling time of Cu CMP slurry. The particle size in slurry has influence on polishing rate and defect. The particles with milling process were assayed with the elapse of time and addition of chemical additives. The results showed that the particle size in slurry became smaller by increasing of bead amount and milling time. Additional milling time was appended to examine agglomeration of particle by milling time. The particle size after milling process became bigger with the increase of time due to absence of dispersion stability. It was confirmed that viscosity and particle size increased sharply with addition of tartaric acid in slurry with alumina-C as abrasive.

Spectroscopic interferences in Fourier transform infrared wine analysis

Fourier transform infrared (FTIR) spectrometry has brought many advantages to wine analysis, such as fast analysis and good precision and accuracy for a great number of parameters. This technology has to be cautiously applied, therefore the need for analytical validation. Recovery results of several current wine control parameters using a FTIR wine analyser were determined. Good results were obtained for ethanol (addition of ethanol), total acid (addition of tartaric acid), total sugars in sweet wines (addition of glucose) and sulfate (addition of sulfuric acid). On the contrary, worse results were obtained for total acid (addition of acetic and sulfuric acids), volatile acid (addition of acetic acid) and total sugars in dry wines (addition of glucose). These findings can be explained by spectroscopic interferences that were also a subject of analysis in this work. In fact, ethanol, organic acids and other compounds, present in high concentrations in wine, can produce major interferences in the analysis for compounds such as volatile acid and sugars in dry wines, when their strong infrared absorption bands do not differ significantly from other abundant compounds.

The effects of carboxylic acid addition on hydrofluoric acid autoclave leaching of a ferrocolumbite

The effects of adding carboxylic acid to the leaching media upon the extraction of niobium and tantalum from a ferrocolumbite are studied. Leaching tests were carried out with a pressure reactor in hydrofluoric and carboxylic acids media. Comparative experiments were performed modifying the following variables: temperature, hydrofluoric acid concentration, solid/liquid ratio and carboxylic acid type and concentration. The reagents and products have been characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDXS), X-ray fluorescence (XRF), X-ray diffraction (XRD), and surface area (BET) measurement. The results obtained show an increase in the niobium and tantalum dissolution when carboxylic acids such as oxalic and tartaric acids are added to the reaction media. The addition of tartaric acid also increases the iron and manganese recovery. The addition of oxalic acid decreases the extraction of manganese, while the extraction of iron is almost nonexistent under certain conditions due to the formation of an insoluble compound that remains in the residue. Results of the residue analysis by XRD show the formation of a new crystalline structure when oxalic acid is used. In experiments with other carboxylic acids such as formic and citric acids, no significant changes in the recovery are observed.

Determination of nanomolar concentrations of phosphate in freshwaters using flow injection with luminol chemiluminescence detection

A simple and rapid flow injection (FI) method is reported for the determination of phosphate (as molybdate reactive P) in freshwaters based on luminol chemiluminescence (CL) detection. The molybdophosphoric heteropoly acid formed by phosphate and ammonium molybdate in acidic conditions generated chemiluminescence emission via the oxidation of luminol. The detection limit (3× standard deviation of blank) was 0.03 μg P l −1 (1.0 nM), with a sample throughput of 180 h −1. The calibration graph was linear over the range 0.032–3.26 μg P l −1 ( r 2=0.9880) with relative standard deviations ( n=4) in the range 1.2–4.7%. Interfering cations (Ca(II), Mg(II), Ni(II), Zn(II), Cu(II), Co(II), Fe(II) and Fe(III)) were removed by passing the sample through an in-line iminodiacetate chelating column. Silicate interference (at 5 mg Si l −1) was effectively masked by the addition of tartaric acid and other common anions (Cl −, SO 4 2−, HCO 3 −, NO 3 − and NO 2 −) did not interfere at their maximum admissible concentrations in freshwaters. The method was applied to freshwater samples and the results ( 26.1±1.1–62.0±0.4 μg P l −1 ) were not significantly different ( P=0.05) from results obtained using a segmented flow analyser method with spectrophotometric detection ( 24.4±4.45–84.0±16.0 μg P l −1 ).