Tartaric Acid Research Articles

Unveiling role of Cu(II) in photochemical transformation and reactive oxygen species production of schwertmannite in the presence of tartaric acid

Unveiling role of Cu(II) in photochemical transformation and reactive oxygen species production of schwertmannite in the presence of tartaric acid

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.

Comparative assessment of pantothenic, aspartic, ascorbic and tartaric acids assisted Pb-phytoextraction by sunflower (Helianthus annuus L.).

Phytoextraction of lead (Pb) is a challenging task due to its extremely low mobility within soil and plant systems. In this study, we tested the influence of some novel chelating agents for Pb-phytoextraction using sunflower. The Pb was applied at control (0.0278mM) and 4.826mM Pb as Pb(NO3)2 through soil-spiking. After 10days of Pb addition, four different organic ligands (aspartic, ascorbic, tartaric, and pantothenic acids) were added to the soil at 1mM concentration each. respectively. In the absence of any chelate, sunflower plants grown at 4.826mM Pb level accumulated Pb concentrations up to 104µgg-1 DW in roots, whereas 64µgg-1 DW in shoot. By contrast, tartaric acid promoted significantly Pb accumulation in roots (191µgg-1 DW; + 45.5%) and shoot (131.6µgg-1 DW; + 51.3%). Pantothenic acid also resulted in a significant Pb-uptake in the sunflower shoots (123µgg-1 DW; + 47.9%) and in roots (177.3µgg-1 DW; + 41.3%). The least effective amongst the chelates tested was aspartic acid, but it still contributed to + 40.1% more Pb accumulation in the sunflower root and shoots. In addition, plant growth, biochemical, and ionomic parameters were positively regulated by the organic chelates used. Especially, an increase in leaf Ca, P, and S was evident in Pb-stressed plants in response to chelates. These results highlight that the use of biocompatible organic chelates positively alters plant physio-biochemical traits contributing to higher Pb-sequestration in sunflower plant parts.

Improving the Solubility, Stability, and Bioavailability of Albendazole through Synthetic Salts.

Albendazole (ABZ) is a highly effective yet poorly water-soluble antiparasitic drug known to form salts (ABZ-FMA, ABZ-DTA, and ABZ-HCl) with fumaric acid (FMA), D-tartaric acid (DTA), and hydrochloric acid (HCl). This research utilized a range of analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), powder X-ray diffraction (PXRD), dynamic vapor sorption (DVS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM), to validate and characterize the solid-state properties of these drug salts. This study also assessed the solubility and intrinsic dissolution rate (IDR) of these salts under different pH conditions compared to the active pharmaceutical ingredient (API) and conducted stability studies. Moreover, the in vivo pharmacokinetic performance of ABZ salt was evaluated. The results of this study reveal that the new solid form of ABZ is primarily associated with amino acid esters and benzimidazole groups, forming intermolecular interactions. All three ABZ salts significantly improved the solubility and dissolution rate of ABZ, with ABZ-HCl demonstrating the optimal performance. Importantly, the drug salt exhibited robust physical stability when exposed to adverse conditions, including strong light irradiation (4500 ± 500 lux), high humidity (92.5 ± 5% relative humidity), elevated temperatures (50 ± 2 °C), and accelerated test conditions (40 °C/75 ± 5% relative humidity). Lastly, the in vivo pharmacokinetic analysis demonstrated that ABZ salt led to a substantial increase in AUC(0-24) and Cmax compared to ABZ. This elevation in solubility in aqueous solvents signifies that ABZ salt exhibits characteristics that can enhance oral bioavailability and pharmacokinetics. These findings provide potential solutions for the development of more effective and innovative drug formulations.

Modification of biodegradable thermoplastic cassava starch/kapok fiber incorporated by tartaric acid and processed by compression molding technique

Thermoplastic starch has been attracted due to its availability, biodegradability, and processability. However, its poor tensile properties, high hydrophilicity and lack of antibacterial activity are still the major concerns for many applications. In current study, several thermoplastic cassava starch samples (THPCS), reinforced with kapok (KP) fibers and modified by varying levels of tartaric acid (TA), a natural organic acid, were prepared to enhance their limitations. All samples were mixed and shaped using an internal mixer and a compression molding machine, respectively. The modified THPCS samples were characterized using analytical techniques such as FTIR, SEM and TGA. Morphology, water uptake, mechanical properties, biodegradability, and antimicrobial performance of various samples were also evaluated. IR peak positions of O–H stretching as well as O–H bending were clearly observed for shifting to lower wavenumbers with the addition of KP fibers or KP fibers/TA, indicating of new H-bond formation. In addition, the use of KP fibers caused the enhancement of mechanical strength and thermal properties including the reduction of water uptake. Moreover, THPCS/KP fiber sample modified by TA presented surface smoothness, good biodegradability, and antibacterial performance against both Staphylococcus aureus and Escherichia coli.

Mimicking chirality floralform heterostructure: A multivariate metal-based nanoparticles with highly charge transformation interface and multivariate recognition

Enantioselective identification of chiral molecules holds immense significance in the fields of biological processes, chemical reactions, and drug development due to the optical rotation properties of enantiomers. Moreover, the chiral nanocomposite plays an important role in capable of selectively interacting with specific chiral molecules. By utilizing the chiral surfaces of metal polyphenol framework, an enantioselective identification chiral nanocomposite is fabricated on polyphenol colloidal spheres (PCS). The multivariate metal-based nanocomposite use L-tartaric acid (TA) and copper as a chiral recognition selector and signal corrector, aminothiophenol (PATP) anchoring Ag NPs as artificial traction skeleton. Applying L-/ D-cysteine as patterns enantiomers, the chiral recognition selector Cu- L-TA framework perform stereoselective recognition of target molecules through strong affinity and hydrogen interaction. The discriminative SERS signal and CT-related totally symmetric (a1) value of Cu- PCS@Ag NPs and PATP molecules is regarded as discriminating part and internal standard to correct the signal drifting. The put forward method has a good linearity in the concentration range of 1 nM ∼ 10 mM and detection limits as low as 0.37 pM and 0.30 pM for L/D-Cys. This work provides specific method for the chiral molecule recognition and determination in complex matrix sample.

Plant Organic Acids as Natural Inhibitors of Foodborne Pathogens

Background: Foodborne infections affect approximately 600 million people annually. Simultaneously, many plants contain substances like organic acids, which have antimicrobial activity. The aim of this study was to examine the effects of 21 organic acids, naturally occurring in plants, on four foodborne bacteria (Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella enterica Typhimurium) and two fungi (Geotrichum candidum and Penicillium candidum). Methods: The minimal inhibitory concentrations (MIC) of the organic acids against foodborne bacteria and in silico toxicity prediction of acids were investigated. Results: Benzoic and salicylic acids exhibit the best activity against foodborne bacteria (mean MIC < 1 mg/mL). Acetic, chlorogenic, formic, malic, nicotinic, and rosmarinic acids demonstrate slightly weaker activity (mean MICs 1–2 mg/mL). Other acids have moderate or poor activity. The effectiveness of organic acids against foodborne fungi is weaker than against bacteria. Most acids require high concentrations (from 10 to >100 mg/mL) to inhibit fungal growth effectively. The predicted LD50 of organic acids ranges from 48 to 5000 mg/kg. Those potentially safe as food preservatives (MIC < LD50) include ascorbic, chlorogenic, malic, nicotinic, rosmarinic, salicylic, succinic, tannic, and tartaric acids. The studied organic acids are not carcinogenic but many can cause adverse effects such as skin sensitization, eye irritation, and potential nephrotoxicity, hepatotoxicity, or neurotoxicity. Conclusions: Most of the investigated plant-derived organic acids exhibit good antibacterial activity and moderate or poor antifungal effects. Among 21 acids, only 9 appear to be safe as food preservatives (MIC < LD50). The relationship between MIC and LD50 is crucial in determining the suitability of organic acids as food preservatives, ensuring that they are effective against bacteria or fungi at concentrations that are not harmful to humans.

Concentrations Influence of Complexing Agents on the Physicochemical Properties of Chemical Bath Deposited n‐Type FeSxOy for Homostructure Solar Cell

A chemical bath deposition (CBD) is applied to deposit n‐type iron sulfide (FeSxOy) film on fluorine (F)‐doped tin oxide (SnO2)–FTO substrate. The duration, temperature, and magnetic stirrer's speed in CBD are 3 h, 75 °C, and 100 revolutions per minute. The influence of complexing agents’ concentration (≤200 mm)–acid (tartaric and lactic) on the physicochemical properties of film is studied. All films are n‐type semiconductors with large bandgap (2.95–3.58 eV) and contain high oxygen (≈56–83%). Scanning electron microscopy image shows the 50 mm tartaric acid film has a uniform and denser surface morphology. FeSxOy film with tartaric acid has lesser goethite and hematite peaks in X‐ray diffraction than lactic acid. The FeSxOy film with 100 mm lactic acid exhibits a slightly higher transmittance at ≈350–450 nm. The FeSxOy homostructure reveals average open‐circuit voltage (Voc) = 0.45 V, short‐circuit current (Jsc) = 0.0003 mA cm−2, fill factor =38%, and efficiency (η) = 0.57%.

Comparative efficacy of citric acid/tartaric acid/malic acid additive-based polyvinyl alcohol-starch composite films

To ascertain upon the ideal configuration of physico-mechanical qualities, efficient processing techniques, and network stability of the prepared bio-composite films in real-world applications, the polymeric materials shall be subjected to a careful manipulation. Such bio-composite films have outstanding combinations of biocompatibility and toxicity-associated safety qualities. Such research interventions will be beneficial for the packaging, pharmaceutical, and biomedical industries that wish to target and adopt them for commercial applications. In this article, three alternate organic acids, i.e., citric acid (CA), tartaric acid (TA), and malic acid (MA), are blended separately into polyvinyl alcohol (PVA)-starch (St)-glycerol (Gl) composite films and for the targeted purpose of enhanced crosslinking, plasticizing, and antibacterial capability of the polymer network. The organic acid-based bio-composite polymeric films were assessed in terms of swelling index (SI), in vitro degradation, tensile strength (TS), percentage elongation (%E), antibacterial activity, and cytotoxicity attributes. Among these, the MA-based PVA composite films outperformed the CA-based PVA composite film in terms of absorbency (SI 739.29%), mechanical strength (TS 4.88 MPa), and elasticity (%E 103.68%). Furthermore, following a 24-h incubation period, the MA-based films exhibited the highest proliferative effect of 215.59% for the HEK cells. In conclusion, the MA has been inferred to be the most relevant organic acid for the desired optimality of film composition, physical and biological properties, and cost.

Fingerprinting of physical manufacturing properties of different acids for effervescent systems

The study aimed to fingerprint the physical manufacturing properties of five commonly used acid sources in effervescent systems for designing the formulation and process of such systems. The hygroscopicity, texture properties, rheological torque, compressibility, tabletability, etc., were investigated to inspect ‘powder direct compression (DC)’ and ‘wet granulation and compression’ properties of citric (CA), tartaric (TA), malic (MA), fumaric (FA), and adipic acid (AA). The DC ability was evaluated by the SeDeM expert system. The results indicated that all acid powders failed to meet flowability requirements for DC, and plastic deformation dominated during compression. Furthermore, CA exhibited strong hygroscopicity and punch sticking, while MA demonstrated the best tabletability. TA had a large wet granulation space and was relatively the most suitable for DC. AA was extremely hygroscopic, and its flowability improved significantly as particle size increased. Finally, FA displayed the lowest hygroscopicity and ejection force as well as great compressibility and wet granulation space, and did not exhibit punch sticking, while the granule fragments dissolved slowly during disintegration. Generally speaking, the formulation or granulation affected the tabletability, indicating that pairing with other acids or suitable fillers could potentially improve its disadvantages. These multidimensional assessments effectively reduce the pre-exploration and enhance the efficiency of the development of effervescent systems.

Characterization of whey protein isolate aggregation induced by different acidic substances: Triggered by disulfide bond formation and recombination

Polymer chemistry of disulfide bond reshuffling in whey protein isolate (WPI) molecules initiated by phosphoric acid (P), malic acid (M), citric acid (C), glutamic acid (G), tartaric acid (T), lactic acid (L), acetic acid (A) was investigated. The disulfide crosslinked sites of acidic substance-treated WPI were accurately identified by LC/MS/MS. Acidic substances treatment rendered the cysteine residues of WPI located at α-La (111), (120) and β-Lg (60), (160) active in the disulfide crosslinking reaction. Meanwhile, the number of intermolecular disulfide crosslinked peptides of P-WPI, T-WPI, and C-WPI increased significantly compared to HWPI, with increases of 9, 8, and 8, respectively. The results of SDS-PAGE and size exclusion chromatography (SEC) indicated that acidic substances promoted the formation of inter-/intramolecular disulfide bonds in WPI, resulting in the generation of polymers. Among them, a large amount of α-lactalbumin was involved in the polymer generation, while β-lactoglobulin was involved to a lesser extent. More aggregates were generated in P-WPI, T-WPI and C-WPI. In addition, fluorescence spectroscopy and fourier transform infrared spectroscopy data demonstrated that acidic substance-treatment led to the transition of the WPI secondary structure from an ordered to disordered structure, as well as the disruption of the tertiary structure. This study explained the disulfide cross-linking mechanism of acidic substances-treated WPI, providing theoretical support for the industrial application of acidifier-modified WPI.

Seven sour substances enhancing characteristics and stability of whey protein isolate emulsion and its heat-induced emulsion gel under the non-acid condition

Protein emulsion gels, as potential novel application ingredients in the food industry, are very unstable in their formation. However, the incorporation of sour substances (phosphoric acid, lactic acid, acetic acid, malic acid, glutamic acid, tartaric acid and citric acid) would potentially contribute to the stable formation of whey protein isolate (WPI) emulsion as well as its gel. Thus, in this work, physical stability of seven acid-treated WPI emulsions, and microstructures, rheological properties, water distribution of its emulsion gels were characterized and compared. Initially, the absolute zeta-potential, interfacial protein adsorption, and emulsifying characteristics of acid-induced WPI emulsions were higher in contrast to acid-untreated WPI emulsions. Moreover, acid-induced WPI emulsions were thermally induced (95 ℃, 30 min) to form its emulsion gel networks via disulfide bonds as the main force (acid-untreated WPI emulsions were unable to form gels). High-resolution microscopic observation revealed that acid-induced WPI in emulsion gel network showed the morphology of aggregates. Dynamic oscillatory rheology results indicated that acid-induced emulsion gel exhibited highly elastic behavior and its viscoelasticity was associated with the generation of protein gel networks and aggregates. In addition, PCA and heatmap results further illustrated that malic acid-induced WPI emulsion gels had the best water holding capacity and gel characteristics. Therefore, this study could provide an effective way for the foodstuffs industry to open up new texture and healthy emulsion gels as fat replaces and loading systems of bioactive substances.

Understand the Stabilization Engineering of Ascorbic Acid, Mapping the Scheme for Stabilization, and Advancement.

Vitamin C is extensively used in cosmetic formulation, howbeit stability is the supreme demerit that limits its use in beautifying products. Numerous techniques are being employed to inhibit the degradation of vitamin C caused by formulation components to facilitate the use in skin rejuvenating products. Diverse materials are being exercised in formulation to stabilize the ascorbic acid and ingredients selected in this formulation composition help for stabilization. The initial stable prototype is developed and further optimization is accomplished by applying the design of experiment tools. The stable pharmaceutical formulations were evaluated for the evaluation parameters and designated as two optimized formulations. The analytical method for the assay of ascorbic acid from the United States pharmacopeia and the related substance method from European pharmacopeia has been modified to be used for cream formulation. The DoE design exhibited that the stability of formulation is impacted by citric acid and tartaric acid but not by propylene glycol and glycerin. The analysis results of topical formulations for the evaluation parameter exhibited satisfactory results. The in-vitro release study method has been developed, optimized, and validated to fit the analysis. The in-vitro studies have been performed for selected compositions and both the formulation has similar kinds of release patterns. The stability study as per ICH guidelines exhibited that the product is stable for accelerated, intermediate, and room-temperature storage conditions. The optimized formulation shows constant release and permeation of ascorbic acid through the skin. The formulation with the combinations of citric acid, tartaric acid, and tocopherol is more stable and the degradation of vitamin C has been reduced significantly. The beaucoup strategies in the unique composition help to protect the degradation by inhibiting the multitudinous degradation pathways.

Circularly Polarized Luminescence from Pure and Eu-Doped Trigonal TbPO4·nH2O Nanocrystals.

In this contribution, we describe the preparation, by means of a precipitation reaction from aqueous solution at 40 °C, and the structural characterization of nanocrystalline powders of trigonal Tb1-xEuxPO4·nH2O (with x = 0, 0.005, 0.01, 0.05, and 0.1; n tentatively assigned as 0.67) which crystallize in the two possible P3121 or P3221 enantiomorphic space groups. While the volume of the crystal lattice is not significantly affected by the Tb3+/Eu3+ substitution, the average crystallite size seems to depend on the Eu3+ dopant concentration and ranges from 13 to 30 nm. The desired handedness of the crystals has been induced by using, during the synthesis, one of the two possible enantiomers of tartaric acid (l or d). The analysis of the luminescence excitation and emission spectra, together with the decay kinetics of the 5D4 Tb3+ excited state, suggests the presence of a very efficient Tb3+ → Eu3+ energy transfer process in the Eu3+-doped orthophosphates. Upon excitation of Tb3+ ions at 368 nm, the enantiomorphic powders grown with l- or d-tartaric acid (i.e., l-TbPO4·0.67H2O/d-TbPO4·0.67H2O, l-Tb0.995Eu0.005PO4·0.67H2O/d-Tb0.995Eu0.005PO4·0.67H2O, and l-Tb0.9Eu0.1PO4·0.67H2O/d-Tb0.9Eu0.1PO4·0.67H2O) exhibited mirror circularly polarized luminescence signals in the visible spectral region (in the green and/or in the red).

Hydrogen bond regulation to promote the direct production of diosgenin from Dioscorea zingiberensis rhizomes

Herein, a renewable system consisted of tartaric acid and isopropanol was developed to produce diosgenin efficiently from Dioscorea zingiberensis rhizomes. The yield of diosgenin reached 4.15% comparable to the highest value reported in previous researches. The combination of experiment and DFT calculation revealed that the acid-alcohol system could regulate the hydrogen bond interaction of each component in the rhizomes to disassemble the connection network and promote the release of saponin. Meanwhile, the intramolecular hydrogen bond of tartaric acid and the steric hindrance effect of isopropanol could prevent the esterification reaction and maintain the strong acidity of the system for the high yield of diosgenin. The scale-up experiment with a 100-fold feeding capacity was also conducted successfully. Furthermore, the technological process integrated with purification of diosgenin, recovery of organic acid and solvent and upgrading of residual solid to porous carbon materials has been established systematically to verify the prospective of industrialization.

Biochemical properties of polyphenol oxidase purified from Sarali plum (Prunus domestica)

Enzymatic browning, catalysed by the enzyme polyphenol oxidase in fruit and vegetables, limits the efficient use of natural resources and promote food waste. Plums are a popular fruit with consumers around the world and are considered an important raw material in the food industry. Plums are very susceptible to enzymatic browning due to their high phenolic compound content and climacteric nature. The aim of this study is to purify the polyphenol oxidase enzyme from Sarali plum (Prunus domestica) and to determine its biochemical properties, kinetic parameters, pH and thermal stability and inhibition. In this study, polyphenol oxidase enzyme was purified 22.54-fold by affinity chromatography using Sepharose-4B-l-Tyr-p-amino benzoic acid affinity gel. The purity and molecular mass of the enzyme were determined by SDS-PAGE and non-denaturing PAGE (native PAGE). The molecular mass of the enzyme was estimated to be 72.44 kDa by SDS-PAGE. The enzyme was confirmed as PPO by native PAGE as a single band. Kinetic characterization studies were conducted for both catechol and 4-methyl catechol substrates. The optimal pH and temperature for both substrates were found to be 7.0 and 20 °C, respectively. The thermal stability of PPO was investigated, and it retained about 90% of its activity for 90 min at 4 °C. The determination of KM and Vmax was carried out using the Lineweaver–Burk plot. The substrate specificity (Vmax/KM) values for catechol and 4-methyl catechol were determined as 790.91 ± 37.34 and 492.06 ± 13.75 respectively. The enzyme exhibited the best activity towards catechol substrate. IC50, Ki constant and inhibition types were determined for various anti-browning agents on PPO enzyme. Ascorbic acid, l-cysteine, citric acid, salicylic acid and tartaric acid effectively inhibited PPO activity.

Antinociceptive and wound healing effects of a commercial formulation of lidocaine, bupivacaine, adrenaline and cetrimide applied topically to superficial skin wounds in horses.

Post-traumatic distal limb wounds cause discomfort and heal gradually by second intention. The topical application of Tri-Solfen (lidocaine hydrochloride, bupivacaine hydrochloride, adrenaline acid tartrate and cetrimide [LBAC]) produces effective postsurgical cutaneous analgesia in lambs, calves and piglets; however, its effect on wounds in horses is unknown. The antinociceptive effect, measured by mechanical threshold (MT), and the wound healing impacts of LBAC compared with saline were investigated on surgically created 20 × 20 mm distal limb wounds in 10 horses. Treatment was applied once daily for 7 days following wounding on day 0. Mechanical thresholds were measured after treatment on days 1, 2 and 3. Healing was observed for 25 days. The topical application of LBAC immediately following wounding and its reapplication 24 hours later increased the average MT on the first post-traumatic day by 3 Newtons. However, no antinociceptive benefit was observed on days 2 or 3. Treatment with LBAC did not adversely affect wound healing when compared with saline. Methodological differences preclude absolute MT comparisons between studies. The experimental design did not include a model of contaminated or naturally occurring wounds. LBAC may provide an early antinociceptive benefit when applied to uncontaminated surgically created wounds without compromising healing.

Impact of low molecular weight organic acids on heavy metal(loid) desorption in biochar-amended paddy soil.

Low molecular weight organic acids (LMWOAs) are important soil components and play a key role in regulating the geochemical behavior of heavy metal(loid)s. Biochar (BC) is a commonly used amendment that could change LMWOAs in soil. Here, four LMWOAs of oxalic acid (OA), tartaric acid (TA), malic acid (MA), and citric acid (CA) were evaluated for their roles in changing Cd and SB desorption behavior in contaminated soil with (S1-BC) or without BC (S1) produced from Paulownia biowaste. The results showed that OA, TA, MA, and CA reduced soil pH with rising concentrations, and biochar partially offset the pH reduction by LMWOAs. The LMWOAs reduced Cd desorption from the soil at low concentrations but increased Cd desorption at high concentrations, and CA was the most powerful in this regard. The LMWOAs had a similar effect on Sb desorption, and CA was the most effective species of LMWOAs. Adding BC to the soil affects Cd and Sb dynamics by reducing the Cd desorption but increasing Sb desorption from the soil and increasing the distribution coefficient (Kd) values of Cd but lowering the Kd values of Sb. This study helped understand the effects of LMWOAs on the geochemical behavior of Cd and Sb in the presence of biochar, as well as the potential risks of biochar amendment in enhancing Sb desorption from contaminated soil.

Influence of tartaric acid on the electron transfer between oxyanions and lepidocrocite

Iron oxide minerals control the environmental behavior of trace elements. However, the potential effects of electron transfer directions by iron oxides between organic acids and trace elements remain unclear. This study investigates the redox capacity of tartaric acid (TA) with chromate (Cr(Ⅵ)) or arsenate (As(V)) on lepidocrocite (Lep) from the perspective of electron transfer. The results demonstrated the configurations of TA (bidentate binuclear (BB)), As(V) (BB), and Cr(Ⅵ) (BB and protonated monodentate binuclear (HMB)) on Lep. Frontier molecular orbital calculations and X-ray photoelectron spectroscopy (XPS) binding energy shifts further indicated different electron transfer directions between TA and the oxyanions on Lep. The iron of Lep might act as electron acceptors when TA is adsorbed, whereas the iron and oxygen of Lep act as electron donors when As(V) is adsorbed. The iron of Lep might accept electrons from its oxygen and subsequently transfer these electrons to Cr(Ⅵ). Macroscopic validation experiments showed the reduction of Cr(VI), whereas no reduction of As(V). The XPS analysis showed a peak shift, with the possible formation of As–Fe–TA ternary complexes and electron transfer on Lep. These findings indicate that mineral interfacial electron transfer considerably influences the transport and transformation of oxyanions.

New tartrate and α-tocopherol based environmentally friendly plasticizers for improvement of the ductility of polylactic acid

This study focuses on developing environmentally friendly plasticized poly(lactide) (PLA) formulations using tartaric acid and α-tocopherol at 20 wt%. The extrusion and injection molding processes demonstrated the industrial applicability of these plasticizers. Mechanical tests revealed positive results for tartrate-based plasticizers, with elongation at break surpassing 220 %, while α-tocopherol succinate achieved 170 %. However, α-tocopherol acetate showed limited PLA plasticization. Field emission scanning electron microscopy confirmed plasticization in fractured surfaces. Thermal analysis indicated a reduction in PLA's glass transition temperature (Tg) from 60 °C to around 30 °C with these plasticizers, underscoring tartrates' exceptional efficiency. The cold crystallization temperature (Tcc) decreased for all plasticized samples due to enhanced chain mobility. Thermomechanical analysis revealed dimensional shrinkage, with dimethyl tartrate (DMT) causing less pronounced effects. Generally, tartrates yielded formulations with superior properties, attributed to their lower molecular weight compared to α-tocopherol-derived plasticizers. Notably, all plasticizers employed are an eco-friendly approach to improve PLA's processability and enhancing ductile properties.