Addition Of Tartaric Acid Research Articles

Modulating Helix-Preference of an Axially-Twisted Molecular Scaffold Through Diastereomeric Salt Formation with Tartaric Acid Stereoisomers.

Herein, we designed a chiral, axially-twisted molecular scaffold (ATMS) using pyridine-2,6-dicarboxamide (PDC) unit as pivot, chiral trans-cyclohexanediamine (CHDA) residues as linkers, and pyrene residues as fluorescent reporters. R,R-ATMS exclusively adopted M-helicity and produced differential response in UV-vis, fluorescence, and NMR upon addition of tartaric acid (TA) stereoisomers allowing naked-eye detection and enantiomeric content determination. Circular dichroism (CD) profile of R,R-ATMS underwent unique changes during titration with TA stereoisomers - while loss of CD signal at 345 nm was observed with equimolar D-TA and meso-TA, inversion was seen with equimolar L-TA. Temperature increase weakened these interactions to partially recover the original CD signature of R,R-ATMS. 2D NMR studies also indicated the significant structural changes in R,R-ATMS in the solution state upon addition of L-TA. Single crystal X-ray diffraction (SCXRD) studies on the crystals of the R,R-ATMS⊃D-TA salt revealed the interacting partners stacked in arrays and ATMS molecules stabilized by π-π stacking between its PDC and pyrene residues. Contrastingly, tightly-packed supramolecular cages comprised of four molecules each of R,R-ATMS and L-TA were seen in R,R-ATMS⊃L-TA salt, and the ATMS molecules contorted to achieve CH-π interactions between its pyrene residues. These results may have implications in modulating the helicity of topologically-similar larger biomolecules.

Antimicrobial effect of plasma-activated water combined with tartaric acid against Staphylococcus aureus and its application on fresh-cut asparagus lettuce

Plasma-activated water (PAW) is increasingly recognized for its role in mitigating microbial contamination in fresh-cut produce, but its disinfection effectiveness can be limited under certain conditions. Notably, dissolving organic acids in PAW is an effective way to boost its antimicrobial properties through a synergistic effect. This study examined the enhanced antimicrobial efficacy of PAW when combined with tartaric acid against Staphylococcus aureus and its application on fresh-cut asparagus lettuce. Results demonstrated that PAW combined with tartaric acid showed stronger antimicrobial efficacy than PAW alone (p < 0.05). The addition of tartaric acid to PAW increased the oxidation-reduction potential and lowered the pH, contributing to its superior antimicrobial performance against S. aureus. The underlying antimicrobial mechanisms included the inactivation of Ca2+-Mg2+-ATPase and Na+-K+-ATPase accompanied by damage to bacterial cell membrane, enhanced oxidative damage due to the influx of extracellular reactive oxygen species such as H2O2, the disrupted energy metabolic activities, and the mitigated bacterial defense system constructed by antioxidant enzymes, such as superoxide dismutase and catalase. Furthermore, the synergistic treatment improved the quality of fresh-cut asparagus lettuce by retarding browning, curbing microbial spoilage, and lessening weight loss. The preservation of color was largely due to the decreased activities of polyphenol oxidase and peroxidase, along with controlled chlorophyll degradation. These findings suggest that PAW enhanced with tartaric acid could be a promising, cost-effective disinfection strategy for fresh-cut asparagus lettuce.

Comparison of residual carbon content and morphology of B4C powders synthesized under different conditions

In this article, the impact of different B4C synthesis methods on the amount of residual carbon and the final morphology of the prepared ceramic particles was investigated. The main materials for the synthesis of B4C were glucose and boric acid, and the effects of adding tartaric acid and performing mechanical activation were studied. For this purpose, two methods of carbon dissolution and boron carbide oxidation were used to determine the amount of residual carbon in the ceramic products. The results of the investigations on the sample synthesized in optimal conditions showed that if additives and mechanical activation are not used, about 7 wt% of carbon will remain in the synthesized powder. The amount of carbon decreased to 5.7 wt% with mechanical activation, but the best result was obtained with the addition of tartaric acid, in which the amount of impurity dropped to 3.3 wt%. Finally, the size and morphology of B4C particles and carbon impurities were observed and compared using a scanning electron microscope.

Effect of Chemical Admixtures on the Working Performance and Mechanical Properties of Cement-Based Self-Leveling Mortar

In this work, the effect of cellulose ether (CE), tartaric acid (TA), and polycarboxylate superplasticizer (PCE) on the working performance and mechanical properties of cement-based self-leveling mortar is investigated. According to the orthogonal experiment analysis, TA is identified as the most influential factor affecting the working performance, as indicated by factors such as fluidity, fluidity loss, and viscosity. Upon conducting a comprehensive assessment of the working performance and mechanical properties, the optimal parameters are found to be CE = 0.6 wt.‰, TA = 0.5 wt.‰, and PCE = 2.0 wt.‰. A univariate test highlights that that the working performance improves with the higher TA dosages. Specifically, the exponential reduction of fluidity loss corresponds with an increased TA content. Regarding the mechanical properties of cement-based self-leveling mortar, the compressive and flexural strength exhibit enhancement when the TA dosage remains below 0.4 wt.‰ at the early stage, implying that TA has some influence on the hydration process. Impressively, the 1 d compressive and flexural strengths surpass 7 MPa and 2 MPa, respectively, ensuring the viability of subsequent construction activities. Through an analysis of hydration heat, the effect mechanism of TA on the cement-based self-leveling mortar is derived. The result shows that the addition of TA decelerates the hydration process within the initial 10 h, followed by acceleration in the subsequent 20 h to 30 h. Consequently, this delayed formation of the early hydration product, ettringite, contributes to a more porous structure in the slurry, with low friction leading to a better working performance. A large number of hydration products, such as alumina gel and calcium–silicon–hydrate gel, presented in the hardened paste results in the good mechanical properties at 1 d. This study may lay a foundation for the optimization of the dosage of chemical admixtures in the self-leveling mortar and high-performance cement-based materials, and also impart valuable insights for practical applications extending to the realm of building construction and decoration.

Exploiting common ion addition to accelerate zolpidem hemitartrate release from Eudragit EPO extrudates

The current study aimed at optimizing a previously developed non-clinical formulation for use in zolpidem deprescribing. The formulation under investigation consists of extruded zolpidem hemitartrate (30% w/w) and Eudragit EPO (70% w/w) mixtures which display unsatisfactory dissolution behavior. Both milled extrudates and physical mixtures were compressed to produce tablets with identical target weight and solid fraction. First, the susceptibility of zolpidem hemitartrate towards heat and shear degradation was identified utilizing thermal and HPLC-DAD analysis. The drug salt proved prone to thermally induced disproportionation. Moreover, the impurity content increased after applying hot melt extrusion although ICH guidelines were still attained. Secondly, extrudates and physical mixtures were subjected to FTIR analysis. As a result, interaction and protonation of the dimethyl aminoethyl group from Eudragit EPO resulting from zolpidem disproportionation was elucidated. As such, the formulations’ slow dissolution kinetics in comparison to formulations containing non-ionizable polymers (e.g. Kollidon 12PF and Kollidon VA64) is explained. Finally, addition of tartaric acid, a microenvironmental pH modulator and common ion, proved a successful method to increase dissolution kinetics. The amount of drug released after 15 min increased drastically from 10 to 40% upon the addition of 5% tartaric acid. Immediate release behavior (80% within 15 min) was however not yet attained.

Effects of tartaric acid on the structure and corrosion resistance for anodizing films of aerospace aluminium alloys

ABSTRACT Anodising films are obtained by anodising 2099 aluminium-lithium alloys in tartaric acid-sulphuric acid solutions with different concentrations. The microscopic surface morphology of the anodic-oxide film is observed by field emission scanning electron microscope (FG-SEM), and the corrosion resistance of the film was investigated by open-circuit potential, electrochemical experiments and neutral salt spray experiments. The results show that the aluminium-lithium alloy can form a uniform and dense anodic oxide film in different concentrations of tartaric acid-sulphuric acid solution. Tartaric acid does not change the film formation mechanism of the anodic oxide film, but reduced the dissolution rate of the oxide film, so that the growth rate and thickness of the oxide film increased first and then decreased with the increase of the tartaric acid concentration in the experimental study. This result generally indicates that the addition of tartaric acid can also significantly improve the corrosion resistance of the anodic-oxide film, and the more detailed features are discussed.

Enhancing the aluminate reaction during OPC hydration by combining increased sulfate content, triethanolamine and tartaric acid

Possibilities for enhancing the aluminate reaction were studied in a mix of OPC blended with 7.9 % hemihydrate (HH) or 7.4 % anhydrite (AH) in combination with different triethanolamine (TEA) dosages. Heat flow calorimetry and quantitative X-ray diffraction (XRD) were performed to study the hydration process. Using anhydrite as an additional sulfate carrier allowed a lower TEA dosage compared to hemihydrate systems to enhance the degree of hydration of C3A. High TEA dosages in hemihydrate systems were found to hinder C3S hydration. Nevertheless, it was possible to push the aluminate reaction ahead of the silicate reaction, thereby enhancing the degree of hydration of C3A. Additionally, the degree of hydration of C3S was not strongly affected when anhydrite and a well-balanced TEA dosage were used. The addition of tartaric acid to OPC-anhydrite-TEA systems retarded the subsequent aluminate reaction.

Influences of mechanical activation and tartaric acid addition on the efficiency of B4C synthesis

In this paper, mechanical activation and tartaric acid addition were employed to reduce the residual carbon and intensify the efficiency of B4C synthesis using glucose and boric acid as starting materials. To investigate the role of mechanical activation on synthesis performance, one sample was subjected to high-energy ball milling before pyrolysis and the other after pyrolysis. To study the role of additives, in the precursor production stage, on synthesis efficiency and residual carbon reduction, different amounts of tartaric acid (0, 5, 10, 25, and 50 wt%) were tested. FT-IR and XRD analyses were used to characterize the bonds created in the precursors and the phases formed during the pyrolysis and synthesis steps, respectively. The results confirmed that mechanical activation before synthesis can improve the synthesis efficiency, but ball milling before pyrolysis did not significantly affect the final synthesis product. The addition of tartaric acid enhanced the formation of B–C bonds; hence, it increased the efficiency of B4C synthesis. The optimum additive amount was 25 wt% and higher amounts weakened the synthesis performance.

Effect of tartaric acid on the early hydration process and water resistance of magnesium oxychloride cement

The main type of cement used worldwide is Portland cement with an annual production of about 4 billion tons and CO2 emissions of about 8% of total global anthropogenic greenhouse gas emissions. One of magnesium binders being investigated to mitigate this negative effect is associated with the use of magnesium oxychloride (MOC) cement. Different from that of Portland cement, the main composition of MOC cement is magnesia rather than calcia. MOC cement has excellent properties, including low carbon, light weight, low thermal conductivity, and high early strength, but it is not extensively applied in practical engineering due to its poor water resistance. This study investigated the effect of tartaric acid (TA) addition on the water resistance of MOC cement, as well as its effect on the setting time, hydration, compressive strength, phase composition, pore structure, and microstructure. The results show that the hydration of MOC cement was a multi-step process. The initial precipitate was 2 Mg(OH)2·MgCl2·2H2O, which was ultimately transformed 5 Mg(OH)2·MgCl2·8H2O. TA can adsorb on the surfaces of MgO particles via a coordination effect, which increased the surface negative charge concentration of MgO. This inhibited the dissolution of MgO and the formation of 2 Mg(OH)2·MgCl2·2H2O, prolonging the setting time of MOC cement. The addition of TA decreased compressive strength and increased the total porosity of MOC cement, however, promoted the formation of amorphous 5 Mg(OH)2·MgCl2·8H2O in matrix, resulting in an improvement in the water resistance, a decrease in dissolved concentration of Cl−, and an increase in the content of gel pores of MOC cement.

Preparation and physicochemical properties of K0.5Na0.5NbO3 ceramics obtained using a modified wet chemistry method

A modified wet chemical method involving different chelating acids was applied to prepare a series of lead-free K0.5Na0.5NbO3 (KNN) piezoelectric ceramics. The microstructural, dielectric, spectral and ferroelectric properties of the obtained ceramics were investigated as part of a comparative study. Thermal characteristics specific to a phase transition were detected via high-temperature HT-XRD, FT-IR and EIS. The obtained sinters were dense and consisted of micro-sized grains. Sinters obtained from powders prepared from oxalic acid with the addition of tartaric acid exhibited lower dielectric constants and lower coercive field values than those synthesized using oxalic acid only (332 vs 399 and 10 vs 9.5 kV⋅cm−1, respectively) measured at room temperature. The KNN ceramics exhibited high conductivity (>10−3 S/cm at 600 °C), dielectric loss (∼200 at 1 kHz) and high remnant polarization (∼310−3 μC/cm2).

Easy-handling semi-floating TiO2-based aerogel for solar photocatalytic water depollution

One of the capital issues of photocatalytic technology is how to use photocatalytic materials in real world conditions. Suspension photocatalysts are the most effective, while the handling and recovery of nanoparticles are very challenging and costly. Herein, we report the design of semi-floating aerogel TiO2-based photocatalyst for the oxidation of dyes and photoreduction of Cr(VI). TiO2 aerogel-based photocatalyst was fabricated through in situ polymerization using borax, poly(vinyl alcohol) and polyvinylidene in the presence of H2O2 as a catalyst. Cubic TiO2 aerogel of few centimetres was designed for the photocatalytic tests under solar light irradiation. TiO2 aerogel showed a good photoactivity against the oxidation of three types of dyes and Cr(VI) photoreduction. In terms of dyes, the kinetics of methylene blue oxidation was the fastest as compared to rhodamine B and methyl red, while, a total reduction of Cr(VI) at 10 ppm was obtained within 30 min after the addition of tartaric acid as hole scavenger. TiO2 aerogel can be easily recovered, washed and recycled. TiO2 aerogel can move freely from the top to the deep solution. The semi-floating property could be an advantage to enhance the mass transfer along with bulk solution, as compared to totally floating-based photocatalysts.

Enhanced properties of starch based foams with modified starch/polyester blend as masterbatch

AbstractStarch/PBAT blends were reactively extruded as masterbatch with the addition of tartaric acid (TA) and epoxide chain extender ADR4468 (ADR). The effects of tartaric acid and chain extender on the mechanical properties and structure of starch/PBAT blends were evaluated. The tensile strength of starch/PBAT blends with TA and TA/ADR increased by 31.4% and 85.6%, respectively. Further, starch, plasticizer, and blowing agent were melt extruded with this blend masterbatch, and the effects of masterbatch on the foamability, morphology, and properties of starch foams were investigated. When the masterbatch content was 10 phr, the obtained foam had the lowest apparent density (445.1 kg m−3), and the compressive strength, recovery, and water resistance of the foam were also improved significantly.

Adhesion properties of tartaric sulfuric acid anodic films assessed by a fast and quantitative peel tape adhesion test

The adhesion capabilities of sulfuric acid and tartaric-sulfuric-acid anodic oxide films on cladded AA2024-T3 aluminium substrates have been investigated in a quantitative manner. A relatively simple, versatile and industrially applicable test methodology based on DIN EN ISO 29862 has been used. In addition, the effect of anodising process parameters on the oxide film morphology has been studied and correlated with the adhesion results. The process parameters considered are the chemistry of the acidic pickling pre-treatment step, the addition of tartaric acid to the sulfuric acid electrolyte, the formation voltage, and the electrolyte temperature. The suggested tape peel adhesion test is able to differentiate among pre-treatments and anodising conditions showing a good correlation with the morphological features at the ultimate surface. High peel adhesion strengths are measured when topographies such as pore mouth widening and dissolution-driven roughness take place. These morphologies are typically found in anodic layers formed at elevated electrolyte temperatures. The proposed method can be beneficial for a fast assessment of anodising parameters for good adhesion, which is of special interest for the industrial optimisation of anodising processes.

The Role of Anodising Parameters in the Performance of Bare and Coated Aerospace Anodic Oxide Films

The anodising process parameters (voltage, temperature, and electrolyte) control the morphology and the chemical composition of the resulting anodic oxide film by altering the balance between oxide growth and oxide dissolution reactions. The porosity of the oxide film is reduced by the addition of tartaric acid to a sulfuric acid electrolyte, while anodising at elevated temperatures enhances oxide dissolution, leading to wider pores and rougher surfaces. No significant changes in the oxide chemical composition as a function of anodising parameters was found; in particular, no tartrate incorporation took place. The resistance of uncoated anodic oxide films against aggressive media and galvanic stress as a function of anodising parameters has been studied by electrochemical methods. Anodising in a mixed tartaric and sulfuric acid electrolyte improves the resistance of the anodic oxide against galvanic stress and aggressive media in comparison to sulfuric acid anodising processes. However, the corrosion protection performance of the anodic oxide films in combination with a corrosion-inhibitor loaded organic coating is not governed by the blank oxide properties but by the adhesion-enhancing morphological features formed during anodising at elevated temperatures at the oxide/coating interface.

Banana flower extract based ZnO nanoparticle in dye-sensitized solar

Banana flowers are the source of anthocyanins that donate electrons to the active component of 2%. ZnO has high exciton binding and high electron mobility of 155-165 m2V−1s−1 compared to TiO2. In this study, the peak absorbance without tartaric acid 100:0% was at 451 nm and the addition of tartaric acid for 6% concentration 95/5 (v/v) experienced a wavelength shift of 543. The highest absorbance peak was at the dye solution with the variation in methanol and tartaric acid of 90:10% that was 545 nm. The addition of tartaric acid solvents successfully increased the conductivity of the natural dye causing the sample to have good sensitized properties so that could be applied as a photosensitizer. The conductivity values of the variation 100:0% were 0.5188 Q−1 m1 and 0.4922 Q−1 m1 in light and dark conditions, respectively. Then, the conductivity values of the variation 94:5 were 0.8806 Q−1 m1 and 0.8065 Q−1 m1 in the light and dark conditions, respectively. The highest conductivity values were at the variation (90/10) those were 1.1566 Q−1 m1 and 1.1077 Q-1 m1 in light and dark conditions, respectively. The DSSC efficiencies obtained 0.037%, 0.078%, and 0.083% for the variation of 100:0%, 95:5%, and 90:10%, respectively.

Improving physicochemical properties of edible wheat gluten protein films with proteins, polysaccharides and organic acid

Wheat gluten protein (WGP) films have a potential to be used to retain freshness of food products due to their ability to insulate water and light. However, the poor mechanical strength, weak water resistance and being prone to rupture have largely limited their practical use in food industry. To overcome these disadvantages, this work modified WGP films by combining with different edible components, including apple pectin (AP), carboxymethyl cellulose (CMC), egg white proteins (EWP) and tartaric acid (TA), respectively. And their physical and functional properties were systematically investigated. The results showed that films made from WGP-CMC had an excellent thermal stability. The addition of EWP endowed WGP films a higher physical strength, with elongation at break of 161.76%. The WGP films with AP were smoother and more homogeneous. The addition of TA improved the water-barrier ability and UV resistance of WGP films, and water vapor permeability reduced from 11.17 to 7.16 when TA was added. This study provides a variety of approaches for preparation of WGP films with enhanced physicochemical and functional characteristics, and holds a great promise for development of edible protein films.

Microwave-assisted recovery of lead from electrolytic manganese anode sludge using tartaric acid and NaOH

ABSTRACT In this study, a new metallurgical system for treating electrolytic manganese anode sludge by microwave roasting and alkaline leaching system was developed, and the lead leaching behaviour was studied. The XRD results show that Pb in anode sludge is mainly in the form of PbSO4 after microwave roasting at 850°C, as a result, the leaching rate of Pb is improved. The results show that the leaching rate of lead can reach 93.89% under the conditions of liquid–solid ratio of 7:1, leaching time of 30 min, leaching temperature of 40°C, and the concentration of sodium hydroxide of 8%. The addition of tartaric acid can further improve the lead leaching rate, FT-IR analysis showed that the coordination form of lead and tartaric acid. Lead and tartaric acid ions (L) form three coordination compounds, PbL, Pb2L2 and Pb2L3, which can only exist in alkaline solution.

Tartaric acid effects on hydration development and physico-mechanical properties of blended calcium sulphoaluminate cements

The fast setting of calcium sulphoaluminate (CSA) cement-based systems is typically controlled using set-retarding admixtures, despite the notable efficiency of tartaric acid (TA) in adjusting CSA-based mixtures setting times, its use has only been marginally investigated, with an almost exclusive focus on the early age properties of TA manufactured mortars. This paper aims at evaluating the effect of the addition of tartaric-acid retarder on the hydration mechanism and physical properties of CSA-based mixtures from 4 h to 84 days. Macro- and microstructural properties were investigated using X-ray diffraction and differential thermal-thermogravimetric analyses, mercury intrusion porosimetry measurements, mechanical tests and analyses at fresh and hardened state. The experimental results reveal that the use of TA delays the formation of ettringite, modifies the porosity of hardened mixtures and strongly reduces strength in the short term. Nevertheless, the addition of TA slightly influences the properties at longer periods.

Study of Struvite Crystal Growth with The Addition of Tartaric Acid

The purpose of this study was to study the growth of struvite crystals from the effect of adding tartaric acid additives to an aqueous solution containing Mg2+, NH4+, and PO43-with a molar ratio of 1:1:1. The results of the study, it was found that the more the concentration of tartaric acid additive was added, it got smaller the rate constant was. By decreasing the value of the constant rate, the growth of struvite crystals also decreased then the growth of struvite crystals became inhibited. On the other hand, struvite has the potential to be used as a fertilizer. The concentration of tartaric acid also had a significant effect on controlling the production of struvite. The optimum crystal mass was obtained at a concentration of 20 ppm tartaric acid, a temperature of 40oC and a stirrer rotation of 300 rpm so that it can be applied in manufacture industry of struvite fertilizer.

Extraction behavior of germanium from synthetic leaching solution of secondary zinc oxide in tertiary amine (N235)-trioctyl phosphate (TOP) system

In continuation with our previous work, in the present study, the tertiary amine-trioctyl phosphate-sulfonated kerosene system was employed to recover Ge(IV) from the synthetic leachate of secondary zinc oxide. The effects of different complexing agents (tartaric acid, citric acid, oxalic acid, gallic acid, and salicylic acid) and impurities (Zn(II), Fe(III), Cd(II), Si(IV), and As(III)) on the extraction of Ge(IV) were investigated. Under comparable conditions, the extraction of Ge(IV) with the aforementioned complexants had the following order in terms of extraction efficiency: tartaric acid > citric acid > gallic acid > oxalic acid, or salicylic acid. The reason for the low extraction efficiency of Ge(IV) with the addition of oxalic acid was revealed by an extraction comparison using pure germanium and polymetallic solutions. Furthermore, a stoichiometry analysis of the extracted complex indicated that the extracted Ge(IV)-organic species was R3NH·Ge(OH)4(HT)·0.5TOP with the addition of tartaric acid. The concentration of Ge(IV) in the loaded organic phase was less than 1 mg/L when three-stage countercurrent stripping was adopted at an O/A ratio of 1/3 and 25 °C for 10.5 min.