Malonic Acid Research Articles

Decarboxylative Organocatalyzed Aldol-Type Addition Reaction of Chloroacetate Surrogates.

Chlorinated malonic acid half thioesters were established as chloroacetate surrogates and used in stereoselective organocatalyzed decarboxylative aldol-type additions. Enantioenriched α-chloro-β-hydroxy thioesters were obtained under mild reaction conditions in high yields and allowed for diverse derivatization as highlighted by the synthesis of (+)-prebalamide and (+)-norbalasubramide analogs.

Differentiation of qualified tea beverages from spoiled ones by the LC-MS–based analysis of their polycarboxylic acids

Abstract Polycarboxylic acids (PACs) are important metabolic products in almost all living bodies, yet current analytical methods for detection of PACs in tea beverages are still unsatisfactory due to the complex matrix and physicochemical properties of PACs. In this work, a rapid method was developed for the simultaneous determination of 7 PACs, including tartaric acid, α-ketoglutaric acid, malic acid, malonic acid, cis-aconitic acid, succinic acid, and fumaric acid, in beverages, based on selective removal of the matrix in combination with liquid chromatography–mass spectrometry (LC-MS) analysis. By stirring with activated carbon and the Na2CO3 solution, the matrix in beverages was selectively removed, and PACs were almost retained in the supernatant of diluted Na2CO3 solution. Under optimized parameters, the limit of quantitation for the PACs was in the range of 1–50 ng/mL, and the content of the PACs in 8 beverages was determined with the recovery range of 72.2%–122.5%. The contents of malic acid, malonic acid, and succinic acid in tea beverages were found to be greater than those in non-tea beverages. Moreover, the concentration of these PACs in beverages was found to be multiplied many times in their deterioration period, especially for fumaric acid and α-ketoglutaric acid. These results indicated that PACs can be selected as a criterion to differentiate qualified tea beverages from spoiled beverages.

Oxidative Desulfurization of Real High-Sulfur Diesel Using Dicarboxylic Acid/H2O2 System

From the perspective of pollution, economics, and product quality, it is very important to find an efficient way to minimize the sulfur content of petroleum products such as gasoline and diesel. In this work, an effective, inexpensive, and simple oxidative desulfurization system based on hydrogen peroxide activation by three dicarboxylic acids which have different carbon numbers (i.e., malonic acid, succinic acid, and glutaric acid) was utilized for the desulfurization of a real diesel sample with high organic sulfur-containing compounds. The desulfurization process was based on the oxidation of sulfur compounds in diesel fuel to the corresponding sulfones followed by acetonitrile extraction of the sulfones. To select the optimal experimental conditions, the effects of several parameters, including temperature, catalyst H2O2 dosages, and treatment time, were investigated. The results showed that the developed system was effective in desulfurizing real diesel fuel with high sulfur content. With an initial total sulfur content of about 8104 mg/L, the desulfurization rate from the diesel sample reached more than 90.9, 88.9, and 93%, using malonic acid, succinic acid, and glutaric acid, respectively. The optimum parameters such as reaction temperature, reaction time, H2O2 (50 w/w%), and carboxylic acid dosage for oxidative desulfurization were determined to be 95 °C, 6 h, 10 mL, and 0.6 g, respectively. The conversion of refractory sulfur compounds into extractable sulfone forms was verified using gas chromatography. Moreover, the kinetic study confirmed that the designed reaction system follows the pseudo-first-order kinetic model.

Characterization of carotenoids in Lycium barbarum fruit by using UPC2-PDA-Q-TOF-MSE couple with deep eutectic solvents extraction and evaluation of their 5α-reductase inhibitory activity.

Carotenoids from Lyciu m barbarum fruits have possessed pharmacological efficacy against eye diseases, cardiovascular disorders, cancer, and benign prostatic hyperplasia. However, the efficient extraction, rapid characterization and activities evaluation of Lycium carotenoids remains a challenge. To concentrate and characterize Lycium carotenoids, we have developed ultrasound-assisted extraction methods with different deep eutectic solvents (DESs) and analyzed carotenoids by ultra-performance convergence chromatography coupled with photo diode array detector and quadrupole time-of-flight mass spectrometry (UPC2-PDA-Q-TOF-MSE). DESs containing choline chloride and malonic acid presented better extraction efficiency and were more environmentally friendly than other extraction methods. Carotenoids were more quickly profiled (in 11min) by UPC2 compared to by UPLC (in 35min), with seventeen main peaks were characterized in the MS fragmentation patterns. The in vitro 5α-reductase inhibitory activity of DESs extracts, fractions and components were subsequently assessed, and the predominant component zeaxanthin dipalmitate (ZD) exhibited potent inhibitory activity. Our study provides a chemical and pharmacological basis for the further development of potential new drugs based on Lycium carotenoids.

Aspartate α-decarboxylase a new therapeutic target in the fight against Helicobacter pylori infection.

Effective eradication therapy for Helicobacter pylori is a worldwide demand. Aspartate α-decarboxylase (ADC) was reported as a drug target in H. pylori, in an in silico study, with malonic acid (MA) as its inhibitor. We evaluated eradicating H. pylori infection through ADC inhibition and the possibility of resistance development. MA binding to ADC was modeled via molecular docking. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of MA were determined against H. pylori ATCC 43504, and a clinical H. pylori isolate. To confirm selective ADC inhibition, we redetermined the MIC in the presence of products of the inhibited enzymatic pathway: β-alanine and pantothenate. HPLC was used to assay the enzymatic activity of H. pylori 6x-his tagged ADC in the presence of different MA concentrations. H. pylori strains were serially exposed to MA for 14 passages, and the MICs were determined. Cytotoxicity in different cell lines was tested. The efficiency of ADC inhibition in treating H. pylori infections was evaluated using a Sprague-Dawley (SD) rat infection model. MA spectrum of activity was determined in different pathogens. MA binds to H. pylori ADC active site with a good docking score. The MIC of MA against H. pylori ranged from 0.5 to 0.75 mg/mL with MBC of 1.5 mg/mL. Increasing β-alanine and pantothenate concentrations proportionally increased MA MIC. The 6x-his tagged ADC activity decreased by increasing MA concentration. No resistance to ADC inhibition was recorded after 14 passages; MA lacked cytotoxicity in all tested cell lines. ADC inhibition effectively eradicated H. pylori infection in SD rats. MA had MIC between 0.625 to 1.25 mg/mL against the tested bacterial pathogens. In conclusion, ADC is a promising target for effectively eradicating H. pylori infection that is not affected by resistance development, besides being of broad-spectrum presence in different pathogens. MA provides a lead molecule for the development of an anti-helicobacter ADC inhibitor. This provides hope for saving the lives of those at high risk of infection with the carcinogenic H. pylori.

Decarboxylative Claisen Condensations with Substituted Malonic Acid Half Oxyesters

AbstractA decarboxylative Claisen condensation involving substituted malonic acid half oxyesters (SMAHOs) as pronucleophiles has been developed. The addition of their magnesium enolates to various acyl donors allows the synthesis of functionalized α-substituted β-keto esters in moderate to excellent yields (13–96%). In addition to acyl chlorides and acid anhydrides, these conditions proved efficient for the use of carboxylic acids as acylating agents, thus allowing to greatly extend the scope of this transformation (32 examples overall).

Physicochemical and Pharmacokinetic Evaluation of Praziquantel Co-Crystals by Varying the Spacer Group of Co-Crystal Formers

The research work focuses on investigating the effects of spacer group (varying aliphatic chain length=n) of co-crystal formers (oxalic acid (OA, n=0), (malonic acid (MA, n=1), (succinic acid (SA, n=2), (glutaric acid (GA, n=3), and (adipic acid (AA, n=4) on the physicochemical properties and oral bioavailability of praziquantel (PZQ) co-crystals. For this purpose, different co-crystals of PZQ with dicarboxylic acid co-crystal formers (OA, MA, SA, GA, and AA) were synthesized. These co-crystals were characterized by powder X-ray diffractometry (XRPD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry (TG) techniques. The in-vitro (solubility and dissolution) and in-vivo pharmacokinetic (P.K) studies were performed for PZQ co-crystals. Additionally, the effect of polymer hydroxypropyl cellulose (HPC) on the formation of PZQ co-crystals was also investigated. According to the study results, PZQ-SA co-crystal showed improved solubility, dissolution, and oral bioavailability. Overall, the solubility, dissolution, and oral bioavailability are consistent with each other. The order of improved solubility, dissolution, and oral bioavailability is observed as consistent like PZQ-SA > PZQ-AA > PZQ-GA > PZQ-OA > PZQ-MA > pure PZQ. Concerning HPC polymer effects, PZQ-OA, PZQ-MA, PZQ-GA, and PZQ-AA co-crystals were formed successfully in the presence of HPC polymer but the PZQ-SA co-crystal was inhibited.

Phase behavior and molecular insights on the separation of dimethyl carbonate and methanol azeotrope by extractive distillation using deep eutectic solvents

Deep eutectic solvents (DESs) exhibit good separation performance as extractants in extractive distillation. In this study, choline chloride (ChCl)-based and tetrabutylammonium bromide (TBAB)-based DESs were prepared using ChCl and TBAB as hydrogen bond acceptors (HBAs) and urea, glycerol (G), malonic acid (MA), and levulinic acid (LA) as hydrogen bond donors (HBDs). Based on the COSMO-SAC model, the possibility of separating the binary azeotropes of methanol (MeOH) and dimethyl carbonate (DMC) using five DESs was verified. The binary azeotropes of MeOH and DMC were separated by extractive distillation using five DESs, and their separation performance was investigated. The experimental results revealed that ChCl-urea had the best separation effect on the binary azeotropes MeOH and DMC. The macroscopic separation phenomenon and microscopic molecular mechanisms were studied systematically. The interaction of the DESs with MeOH and DMC was investigated at the molecular level by quantum chemical (QC) calculations, and the important role of the hydrogen bond of the DESs in extractive distillation was revealed. The experimental and QC results demonstrate that DESs have a significant effect on the intermolecular forces and can effectively separate azeotropes.

Box-Behnken Optimization and Theoretical Study for Copper Leaching from Scrap Laptop Computer Printed Circuit Board by Malonic Acid and Hydrogen Peroxide

The hydrometallurgical method of copper leaching from scrap electronics is commonly undertaken using pulverized printed circuit boards. Though studies on the use of organic acids like citric and oxalic acids for copper removal are well documented, those on the use of malonic acid are rare. Herein, we report on the investigation of the efficiencies of mixtures of malonic acid and hydrogen peroxide for copper leaching from unpulverized scrap PCB by the Box-Behnken design and the theoretical determination of the most stable copper-malonic acid complex. The average copper content in each unpulverized printed circuit board was found to be (0.84 ± 0.13) mg/g following aqua-regia digestion and atomic absorption spectrophotometry measurement. The conditions at which the highest leaching efficiency of 51.3% was obtained were a malonic acid concentration of 0.5 M, a hydrogen peroxide concentration of 1.0 M, and a contact time of 75 min. The contact time was the most significant individual parameter that influenced the efficiency of copper leached with a p-value of 0.001. Theoretical calculations show that malonic acid prefers to coordinate with copper in a 2:1 malonic acid: copper ratio. This study shows that appreciable amounts of copper can be leached from the minimally processed unpulverized printed circuit board.

Synthesis and characterization of novel molybdovanadophosphoric acid supported kaolin hybrid catalyst for Chromotrope 2R dye degradation in water

The present study provides a complete perspective of recyclable molybdovanadophosphoric acid immobilized on kaolin (MVPA/Kaolin), a hybrid material for catalytic degradation of the dye, Chromotrope 2R in water under mild reaction conditions. Novel MVPA/Kaolin was synthesized with an advanced impregnation method. The material was characterized with PXRD, FTIR, ICP-OES, SEM–EDX, TEM, TGA, surface area, porosity, and 31P NMR measurements. The material that can be classified as a Keggin type catalyst, could be used for hydrogen peroxide oxidation of aromatic azo (–N=N–) dyes with –OH and –SO3H functional groups. The degradation showed excellent conversion of 99.1% under optimum conditions of normal pressure and 60 °C temperature. Products like malonic acid and oxalic acid have been identified as the final products with GC–MS analysis. The present work has demonstrated the application of a simple and effective catalyst for degradation of azo dyes and the catalyst had the reusability capacity of up to six cycles without loss in performance.

Detection of anthrax biomarker and metallic ions in aqueous media using spherical-shaped lanthanide infinite coordination polymers

We report a lanthanide-based infinite coordination polymer (ICP) system synthesized using pyrazole-3,5-dicarboxylic acid as linker, malonic acid as coordination modulator and water as solvent. The precursors self-assembly into microspherical particles, which are water-stable and exhibit excellent dispersibility. Bimetallic samples based on Tb3+ doped with Eu3+ were investigated as ratiometric dipicolinic acid (DPA) sensors, which is a biomarker for Bacillus anthracis spores. Along with the calibration curves, a detection in a real sample extracted from Bacillus subtilis (model organism) was performed. The samples proved to be highly sensitive and selective for ratiometric DPA detection. In a secondary study, the monometallic sample containing only Tb3+ was also investigated as a sensor for ionic species in aqueous media. The Cr3+, Fe3+, Cu2+, and Cr2O72− ionic species could be detected in water by luminescence quenching mechanism. Therefore, we found that the reported ICP system can be judiciously constructed in order to act as a multimodal probe for several chemical species.

Tree species is more effective than season dynamics on topsoil function andCO2emissions in the temperate forests

AbstractSoil respiration is one of the most important operations controlling carbon (C) erosion from territorial ecosystems and a useful index of whole underground allocation of C and stand efficiency. However, how tree species effects root (i.e., autotrophic respiration) and soil microbial respiration (i.e., heterotrophic respiration), based on precise experiential schemes, are still restricted, even though crucial to guide the selection of species for reforestation and C management purposes. This research was done to study how tree species effect soil characteristics and function at stand level and which are the main drivers of soil CO2emission in mixed temperate forests in northern Iran (Mazandaran province). Four most common tree species at the experimental site (Parrotia persica,Ulmus minor,Quercus castaneifolia, andPopulus caspica) that surrounded by same species, were selected. Around each selected tree, four replicates of soil and litter samples were taken from (30 × 30 × 15 cm) and mixed to characterize soil physicochemical characteristics (i.e., bulk density, texture, water content, pH, electrical conductivity, N, organic carbon, and available P, K, Mg, and Ca), basal respiration and substrate (i.e., D‐manitol, D‐glucose, L‐asparagine, L‐arginine, gluconic acid, quinic acid, succinic acid, malonic acid, D‐glucosamine, L‐glutamine) induced respiration. In the litter characteristics, total N, C (OC), and C/N ratio were measured. Our results confirmed that soil chemical properties are more sensitive to species composition than soil physical ones. Moreover, individual tree species in mixed deciduous forests strongly influence induced microbial respiration, independently of the used substrates. On the contrary, season was the major factor explaining variations of basal respiration.

Green electrocatalytic Assembling of Salicylaldehydes, Kojic Acid, and Malonic Acid Derivatives into 2‐amino‐4H‐chromenes as Potent Anti‐inflammatory Agents

AbstractGreen electrocatalytic multicomponent assembly of salicylaldehydes, kojic acid and malonic acid derivatives in n‐propanol in the presence of potassium iodide as an electrolyte in an undivided cell results in the formation of 4‐(3‐hydroxy‐6‐(hydroxymethyl)‐4‐oxo‐4H‐pyran‐2‐yl) substituted 2‐amino‐4H‐chromenes in 86–98 % yields. This new electrocatalytic multicomponent process is a facile and efficient environmentally benign way to the functionalized 2‐amino‐4H‐chromenes, containing in the fourth position kojic acid fragment, which are perspective compounds for different biomedical applications, among them in the treatment of human inflammatory diseases. Python‐automated docking procedure was carried out and the results support anti‐inflammatory potential of the synthesized compounds.

Contribution of dicarboxylic acids to pyrene biodegradation and transcriptomic responses of Enterobacter sp. PRd5.

The colonization of degrading endophytic bacteria is an effective means to reduce the residues of polycyclic aromatic hydrocarbons (PAHs) in crops. Dicarboxylic acids, as the main active components in crops, can affect the physiological activities of endophytic bacteria and alter the biodegradation process of PAHs in crops. In this study, malonic acid and succinic acid were selected as the representatives to investigate the contribution of dicarboxylic acids to pyrene biodegradation by endophytic Enterobacter sp. PRd5 in vitro. The results showed that dicarboxylic acids improved the biodegradation of pyrene and altered the expression of the functional gene of strain PRd5. Malonic acid and succinic acid reduced the half-life of pyrene by 20.0% and 27.8%, respectively. The degrading enzyme activities were significantly stimulated by dicarboxylic acids. There were 386 genes up-regulated and 430 genes down-regulated in strain PRd5 with malonic acid, while 293 genes up-regulated and 340 genes down-regulated with succinic acid. Those up-regulated genes were distributed in the functional classification of signal transduction, membrane transport, energy metabolism, carbohydrate metabolism, and amino acid metabolism. Malonic acid mainly enhanced the central carbon metabolism, cell proliferation, and cell activity. Succinic acid mainly improved the expression of degrading gene. Overall, the findings of this study provide new insights into the regulation and control of PAH stress by crops. KEY POINTS: • Dicarboxylic acids improved the biodegradation of pyrene by Enterobacter sp. PRd5. • The degrading enzyme activities were stimulated by dicarboxylic acids. • There are different facilitation mechanisms between malonic acid and succinic acid.

Microbiome-metabolome analysis reveals alterations in the composition and metabolism of caecal microbiota and metabolites with dietary Enteromorpha polysaccharide and Yeast glycoprotein in chickens.

The intestinal microbiome is responsible for the fermentation of complex carbohydrates and orchestrates the immune system through gut microbiota-derived metabolites. In our previous study, we reported that supplementation of Enteromorpha polysaccharide (EP) and yeast glycoprotein (YG) in combination synergistically improved antioxidant activities, serum lipid profile, and fatty acid metabolism in chicken. However, the mechanism of action of these polysaccharides remains elusive. The present study used an integrated 16S-rRNA sequencing technology and untargeted metabolomics technique to reveal the mechanism of action of EP+YG supplementation in broiler chickens fed basal diet or diets supplemented with EP+YG (200mg/kg EP + 200mg/kg YG). The results showed that EP+YG supplementation altered the overall structure of caecal microbiota as evidenced by β diversities analysis. Besides, EP+YG supplementation changed the microbiota composition by altering the community profile at the phylum and genus levels. Furthermore, Spearman correlation analysis indicated a significant correlation between altered microbiota genera vs serum cytokine levels and microbiota genera vs volatile fatty acids production. Predicted functional analysis showed that EP+YG supplementation significantly enriched amino acid metabolism, nucleotide metabolism, glycan biosynthesis and metabolism, energy metabolism, and carbohydrate metabolism. Metabolomics analysis confirmed that EP+YG supplementation modulates a myriad of caecal metabolites by increasing some metabolites, including pyruvic acid, pyridoxine, spermidine, spermine, and dopamine, and decreasing metabolites related to lipid metabolisms such as malonic acid, oleic acid, and docosahexaenoic acid. The quantitative enrichment analysis results further showed that glycolysis/gluconeogenesis, citric acid cycle, tyrosine metabolism, glycine, serine, and threonine metabolism, and cysteine and methionine metabolism were the most important enriched pathways identified with enrichment ratio >11, whereas, fatty acid biosynthesis and biosynthesis of unsaturated fatty acids pathways were suppressed. Together, the 16S-rRNA and untargeted metabolomics results uncovered that EP+YG supplementation modulates intestinal microbiota and their metabolites, thereby influencing the important metabolism pathways, suggesting a potential feed additive.

Stable Hole-Transporting Material-Free Perovskite Solar Cells with Efficiency Exceeding 14% via the Introduction of a Malonic Acid Additive for a Perovskite Precursor

Hole transport material-free perovskite solar cells (HF-PSCs) offer low-cost photovoltaic devices. For development and commercialization, they are more attractive than the expensive HTL-contained perovskite solar cells. Herein, we focused on enhancing the stability and efficiency of HF-PSCs with the malonic acid (MA) addition to the methylammonium lead iodide. The introduced additive increases the perovskite crystallinity and assembles a perovskite layer with larger grains along with fewer surface defects. In addition, the MA-modified HF-PSCs show suppressed charge recombination within devices, and a lower charge trap density has been obtained for them. A considerable power conversion efficiency of 14.14% is achieved for MA-modified HF-PSCs, higher than the performance of 11.88% for the untreated HF-PSCs. Finally, MA-based HF-PSCs show higher shelf stability than the control HF-PSCs. It is because the MA-modified perovskite layer with passivated grain boundaries is better at repelling water.

Optimization of ultrasonic-assisted deep eutectic solvent for the extraction of polysaccharides from Indocalamus tessellatus leaves and their biological studies

To the valorization of Indocalamus tessellatus（I.tessellatus） leaves for the functional food industry, the process of ultrasonic-assisted deep eutectic solvent (DES) extraction of I.tessellatus leaves polysaccharides (U-DES-ICP) was optimized by response surface methodology. In comparison to ultrasonic extracted polysaccharides (UICP) and water extracted polysaccharides (WICP), their physicochemical properties were analyzed by HPLC, HPGPC-MALLS, and FTIR, and the structure morphology was observed by SEM. Their antioxidant activities were evaluated based on DPPH and ABTS + assay as well. The results showed that the best DES system for U-DES-ICP was a mixture of choline chloride and malonic acid in the molar ratio of 1:4 (10% water content). The highest yield of U-DES-ICP (0.6812%) was obtained by following optimized conditions: 60 min of sonication time, 17 mL/g of liquid-solid ratio, 500W of sonication power, and 63.5 °C of sonication temperature, which was significantly higher than that of the conventional methods. The structural analysis indicated that U-DES-ICP had more uronic acid with higher molecular weight compared with UICP and WICP, the relative content of uronic acid of U-DES-ICP reached 8.364%, which was twice as much as the other two polysaccharides; its molecular weight reached up to 6.201 × 103 KD, and the highest values of molecular weight of UICP and WICP were 1.684 × 103 KD and 995.4 KD, U-DES-ICP which were confirmed by SEM. The antioxidant assays reflected that U-DES-ICP possessed stronger scavenging capacities both on DPPH and ABTS + radicals with IC50 (0.48 mg/mL and 0.61 mg/mL) than the other two biomacromolecules. IC50s for DPPH and ABTS radical scavenging by UICP were 0.51 and 0.73 mg/mL, while 0.82 and 0.94 mg/mL were IC50s for both radical scavenging by WICP, respectively. Therefore, this study evidenced that a novel DES system could boost the extraction of I.tessellatus leaves polysaccharides, which produced a higher yield of product with stronger biological activities compared with traditional techniques.

The Role of Nanoparticle Catalysis in the Nylon Production

Renewal in the world production of plastics with growing amounts of building blocks from biomass is a pressing demand among society. Adipic acid is one of the monomers of nylon 6,6, and, traditionally, is obtained from fossil sources, but it is possible to reduce the muconic acids, deriving it from biomass, to obtain adipic acid. However, these catalyzed reactions use commonly hazardous conditions or reagents; in this study, a pathway to obtain a bio-adipic acid, following the Green Chemistry, is reported. Metal nanoparticles (M NPs; M = Pd, Pt, Ru, Rh) were synthesized in water at 80 °C using sodium lignosulphonate as a reducing and stabilizing agent. They were characterized by TEM and XRD techniques: Pd NPs were larger (21 nm) and spherical in shape; Pt NPs were irregular; Ru and Rh NPs were smallest (1.9 and 5.3 nm, respectively). M NPs were tested as catalyst in the hydrogenation reactions of dicarboxylic acids (fumaric, malonic, trans,trans- and cis,cis-muconic acids) in water at room pressure and temperature. The NPs transformed selectively fumaric and malonic acids to succinic acid, although with different yields. Ru and Pt NPs were moderately active while with Pd NPs, 80% of succinic acid was obtained and with Rh NPs, 100% was observed. Carrying out the hydrogenations on muconic acids at pH 5, the formation of adipic acid was observed with all NPs but selectivities in the presence of Ru, Pt and Pd NPs were not excellent. The selectivity with Rh NPs was remarkable (86% from cis,cis- and about 100% from trans,trans-muconic acid) considering the mild conditions; furthermore, it is attractive that the adipic acid was obtained also from the cis,cis isomer which can be produced from biomass.

Electrodeposition of Ni-Fe Alloy in Presence of Complexing Agent

The nickel-iron alloys have been widely used for versatile soft magnetic applications and electro-magnetic applications due to their magnetic properties for a long time. Also, it has been discovered that Ni-Fe alloy near 36 wt% Ni shows almost zero thermal expansion composition(CTE) in a wide temperature range (~150 ℃). The phenomenon showing low CTE in a specific composition is called the Invar effect. Due to the Invar effect, Invar alloys are used for temperature-sensitive applications such as oscillators and fiber-optic package parts. Invar alloy films are used for fine metal masks, an essential part of OLED fabrication. The invar film currently in use is fabricated using the pyrometallurgy method, more than 20um thick. However, miniaturization and high performance of the products require the thinner thickness of the Invar film, around 10um thick which shows the need for a bottom-up fabrication process of invar film. There are various methodologies to fabricate thin films, such as thermal evaporation, sputtering, CVD, and electrodeposition. Most fabricating processes are the vacuum process, a high-cost and non-continuous process. On the other hand, electrodeposition is a non-vacuum process, relatively low-cost, large-scale, and continuous process.Despite these advantages, there are some obstacles to gaining the Invar thin film by electrodeposition, such as anomalous deposition, composition uniformity, and higher CTE of electrodeposited Invar film. There are researches[1-3] about electrodeposited Ni-Fe thin films in the aspect of CTE, magnetic properties, crystal structures, etc. However, very few researchers have seen the effect of complexing agents other than specific complexing agents such as boric acid and ascorbic acid. In addition, Ni-Fe electrodeposition shows very different results depending on temperature and agitation, but no research confirms the effect on various complexing agents under the same condition.In this study, we synthesized Ni-Fe alloy thin film by electrodeposition in the presence of various complexing agents with different functional groups (amine, carboxyl, alcohol, etc.) such as glycolic acid, malonic acid, ethylenediamine, etc. on 20um stainless 304 foil substrates. The electrodeposition was conducted under the aqueous acidic bath(pH 2) at 55℃. Electrochemical studies were conducted to set appropriate potential and current density for electrodeposition. The thin film was characterized by SEM, EDS, XRD, and copper strip tests to observe the difference in composition, surface morphology, phase, and internal stress.

Titanium Carboxylate Molecular Layer Deposited Hybrid Films As Protective Coatings for Lithium-Ion Batteries

Thirty years after the release of the first commercial lithium-ion battery, capacity fading due to complex ageing mechanisms remains one of the major concerns in lithium-ion battery research. Lithium-ion battery cathodes age due to phenomena as transition metal dissolution, electrolyte oxidation and volume expansions.[1] To suppress these effects, a protective coating can be applied to the cathode’s surface to avoid direct contact with the liquid electrolyte. Many studies exist in literature, showing the protective effect of conformal and pinhole-free Atomical Layer Deposited (ALD) coatings. However, the inorganic coatings deposited by ALD are rigid and will crack upon volume expansion of the cathode.[2]Molecular Layer Deposition (MLD) offers the same benefits as ALD but can be used to deposit hybrid inorganic/organic flexible films that can accommodate potential volume expansions of the cathode. To our knowledge, apart from ‘metalcones’ i.e. MLD films grown using a metal containing precursor and an alcohol, MLD films remain to be explored as protective and flexible coatings for lithium-ion batteries.[3] In this work, hybrid MLD titanium carboxylate thin films are deposited using tetrakis(dimethylamido)titanium (TDMAT) and various dicarboxylic acid precursors: oxalic acid, malonic acid, succinic acid, glutaric acid and 3,6-dioxaoctanedioic acid. The latter containing two ethylene oxide units per molecule, potentially increasing the lithium-ion conductivity.[4]The growth of the titanium carboxylate MLD processes is studied using in situ ellipsometry at a substrate temperature of 100 °C and 160 °C. Only the TDMAT/oxalic acid process is found to display good saturation behavior, while a parasitic CVD component is present during the TDMAT pulse for the other processes. The structure of the as-deposited films is physically characterized using Fourier Transform IR spectroscopy (FTIR) and X-Ray Photoelectron Spectroscopy (XPS), confirming the successful deposition of titanium carboxylate films. The films are found to be stable in air up to 50 days as shown by FTIR. This is in contrast to many metalcone MLD films which are considered to be air sensitive as the organic backbone degrades upon air exposure. In addition, FTIR, X-Ray Reflectivity (XRR) and X-Ray Fluorescence (XRF) measurements show that the titanium carboxylate films remain intact upon immersion into a solution of 1 M LiClO4 in propylene carbonate, the liquid electrolyte used for electrochemical characterization.The electrochemical properties of a 5 nm TDMAT/oxalic acid, TDMAT/3,6-dioxaoctanedioic acid and TDMAT/glycerol film (conventional titanicone film [5]) are tested on top of three ideal electrode systems: anatase TiO2, TiN and LiMnO2 (LMO). The titanium carboxylate films are observed to have little to no effect on the lithium-ion kinetics of the TiO2 electrode system compared to the uncoated electrode. This is in contrast to the titanicone film displaying a detrimental effect on the kinetics. All films are observed to effectively suppress electrolyte oxidation when exposing the TiN electrode system to elevated potentials. On the LMO electrode an activation step is necessary for all films, after which a good lithium-ion mobility through the titanium carboxylate films is observed without the severe irreversible reactions detected in the potential profile for the titanicone films. Overall, the explorative tests on thin film electrodes in this work indicate that the electrochemical properties of the titanium carboxylate films seem promising candidates as protective and flexible coating of lithium-ion battery cathodes.[1] Vetter, J., Novák, P., Wagner, M. R., Veit, C., Möller, K. C., Besenhard, J. O., ... & Hammouche, A. (2005). Ageing mechanisms in lithium-ion batteries. Journal of power sources, 147(1-2), 269-281.[2] Ban, C., & George, S. M. (2016). Molecular layer deposition for surface modification of lithium‐ion battery electrodes. Advanced Materials Interfaces, 3(21), 1600762.[3] Zhao, Y., Zhang, L., Liu, J., Adair, K., Zhao, F., Sun, Y., ... & Sun, X. (2021). Atomic/molecular layer deposition for energy storage and conversion. Chemical Society Reviews, 50(6), 3889-3956.[4] Xue, Z., He, D., & Xie, X. (2015). Poly (ethylene oxide)-based electrolytes for lithium-ion batteries. Journal of Materials Chemistry A, 3(38), 19218-19253.[5] Van de Kerckhove, K., Mattelaer, F., Deduytsche, D., Vereecken, P. M., Dendooven, J., & Detavernier, C. (2016). Molecular layer deposition of “titanicone”, a titanium-based hybrid material, as an electrode for lithium-ion batteries. Dalton Transactions, 45(3), 1176-1184.