Malonic Acid Solution Research Articles

Nucleation of Methane Hydrate from Water and Aqueous Solutions of Malonic Acid in Glass Cells with Varying Surface Hydrophilicity

Nucleation of Methane Hydrate from Water and Aqueous Solutions of Malonic Acid in Glass Cells with Varying Surface Hydrophilicity

Electrochemistry of copper post-CMP cleaning examined in combination with brush-scrubbing in a malonic acid solution

Post-CMP cleaning (PCMPC) is used in the fabrication of integrated circuits to remove unwanted residues of chemical mechanical planarization (CMP) from wafer surfaces. PCMPC combines (electro)chemical surface reactions in a cleaning solution with mechanical scrubbing by a brush. Using tribo-electrochemical protocols, the present work simultaneously probes the (electro)chemical and mechanical functions of PCMPC and determines the corresponding cleaning efficiency. Employing malonic acid as a cost effective, environmentally compatible cleaning solution for copper, it is demonstrated how this electroanalytical approach can facilitate the tasks of developing and evaluating effective PCMPC solutions. The results indicate that malonic acid in a pH neutral environment removes Cu-oxides and their co-adsorbed organic residues of CMP. A detailed electrochemical procedure is illustrated for quantifying the residue removal efficiency of PCMPC, and the role of brush scrubbing in the overall cleaning process is identified.

The study of the interactions of malonic acid ions with the hydroxyapatite surface in liquid

• Adsorption is described by the multiexponantiate model. • The last stage of the adsorption kinetics indicates the process of precipitation of a new phase. • Adsorption of malonic acid is best described by the Redlich-Paterson isotherm model. • The presence of adsorbed malonate ions causes an increase in the concentration of acid groups on the hydroxyapatite surface. Adsorption of malonic acid at the hydroxyapatite/aqueous NaCl solution interface based on the measurements of adsorption / desorption kinetics and adsorption as a function of pH was presented. The adsorption of malonate ions was determined from the loss of ion concentration in the solution as measured by the radioisotope using 14C labeled malonic acid. The adsorption measurements were supplemented with electrophoretic zeta potential as well as and FTIR measurements. The kinetics of adsorption from a solution with an initial concentration of 1 mmol/dm3 of malonic acid proceeds in three stages, in the last stage there was observed a rapid increase in adsorption, which proves the precipitation of a new phase by the malonate ions. The presence of this phase was confirmed by examining the crystallinity of the hydroxyapatite sample conditioned in a malonic acid solution by the method of Landi et al. on the basis of XRD patterns and measurements of particle distribution using the light scattering method.

Development of a UPLC-FLD method for quantitative analysis of three tetracyclines and two fluoroquinolones in chicken muscle

A sensitive, rapid and efficient ultra-performance liquid chromatography-fluorescence detection (UPLC-FLD) method was established for detecting tetracycline (TC), oxytetracycline (OTC), doxycycline (DOX), enrofloxacin (ENR) and ciprofloxacin (CIP) residues in chicken muscle. Moreover, the fluorescence detector output signals were processed by dual-channel detection. The samples were extracted with a mixture of acetonitrile and 0.1 M citric acid containing 100 mM magnesium chloride (1:1, V/V, adjusted the pH to 5.0 with ammonia) using liquid-liquid extraction (LLE) and purified by Oasis PRiME hydrophilic-lipophilic balance (HLB) solid-phase extraction (SPE) cartridges (60 mg/3 mL). The target compounds were separated on an ACQUITY UPLC BEH C18 (100 mm × 2.1 mm, 1.7 μm) chromatographic column using a mobile phase composed of acetonitrile and 0.1 M malonic acid solution containing 50 mM magnesium chloride hexahydrate, and the pH was adjusted to 5.5 by adding ammonia. The limits of detection (LODs) and limits of quantification (LOQs) of the five target compounds in chicken muscle were 0.1–13.1 μg/kg and 0.4–39.4 μg/kg, respectively. The recoveries of the five target compounds in chicken muscles were above 87.33 % when the spiked concentrations were at the LOQ, 0.5 maximum residue limit (MRL), 1.0 MRL and 2.0 MRL. The intraday relative standard deviations (RSDs) were less than 4.91 %, and the interday RSDs were less than 5.13 %. Ultimately, this novel detection method was successfully applied to the quantitative analysis of TC, OTC, DOX, ENR and CIP in 20 commercial chicken samples from local supermarkets.

Peculiar Porous Aluminum Oxide Films Produced via Electrochemical Anodizing in Malonic Acid Solution with Arsenazo-I Additive.

The influence of arsenazo-I additive on electrochemical anodizing of pure aluminum foil in malonic acid was studied. Aluminum dissolution increased with increasing arsenazo-I concentration. The addition of arsenazo-I also led to an increase in the volume expansion factor up to 2.3 due to the incorporation of organic compounds and an increased number of hydroxyl groups in the porous aluminum oxide film. At a current density of 15 mA·cm−2 and an arsenazo-I concentration 3.5 g·L−1, the carbon content in the anodic alumina of 49 at. % was achieved. An increase in the current density and concentration of arsenazo-I caused the formation of an arsenic-containing compound with the formula Na1,5Al2(OH)4,5(AsO4)3·7H2O in the porous aluminum oxide film phase. These film modifications cause a higher number of defects and, thus, increase the ionic conductivity, leading to a reduced electric field in galvanostatic anodizing tests. A self-adjusting growth mechanism, which leads to a higher degree of self-ordering in the arsenazo-free electrolyte, is not operative under the same conditions when arsenazo-I is added. Instead, a dielectric breakdown mechanism was observed, which caused the disordered porous aluminum oxide film structure.

Chemical Deposition of Polycrystalline Znse Thin Films from Malonic Acid Solution: Nucleation and Growth Mechanism, Structural, Optical and Electrical Studies

Chemical Deposition of Polycrystalline Znse Thin Films from Malonic Acid Solution: Nucleation and Growth Mechanism, Structural, Optical and Electrical Studies

An Improved Comparison of Chemometric Analyses for the Identification of Acids and Bases With Colorimetric Sensor Arrays.

Colorimetric sensor arrays incorporating red, green, and blue (RGB) image analysis use value changes from multiple sensors for the identification and quantification of various analytes. RGB data can be easily obtained using image analysis software such as ImageJ. Subsequent chemometric analysis is becoming a key component of colorimetric array RGB data analysis, though literature contains mainly principal component analysis (PCA) and hierarchical cluster analysis (HCA). Seeking to expand the chemometric methods toolkit for array analysis, we explored the performance of nine chemometric methods were compared for the task of classifying 631 solutions (0.1 to 3 M) of acetic acid, malonic acid, lysine, and ammonia using an eight sensor colorimetric array. PCA and LDA (linear discriminant analysis) were effective for visualizing the dataset. For classification, linear discriminant analysis (LDA), (k nearest neighbors) KNN, (soft independent modelling by class analogy) SIMCA, recursive partitioning and regression trees (RPART), and hit quality index (HQI) were very effective with each method classifying compounds with over 90% correct assignments. Support vector machines (SVM) and partial least squares - discriminant analysis (PLS-DA) struggled with ~85 and 39% correct assignments, respectively. Additional mathematical treatments of the data set, such as incrementally increasing the exponents, did not improve the performance of LDA and KNN. The literature precedence indicates that the most common methods for analyzing colorimetric arrays are PCA, LDA, HCA, and KNN. To our knowledge, this is the first report of comparing and contrasting several more diverse chemometric methods to analyze the same colorimetric array data.

Volumetric properties of aqueous solutions of malonic acid

Densities of aqueous solutions of malonic acid in the (0.01–1.0) mole·kg−1 concentration range were measured at 5K intervals, from 278.15K to 343.15K. These densities served to determine the apparent molar volumes. Changes of densities with temperature permitted evaluation of the cubic expansion coefficients and the derivatives of isobaric heat capacities with respect to pressure which are interrelated with the second derivatives of volume with respect to temperature. Thermal dependence of volumetric properties of aqueous solutions of malonic acid is examined in terms of changes in the structure of water.

Preparation and characterization of poly(NIPAAm-co-AMPS-co-Fe(phen)3) self-oscillating copolymers

A novel self-oscillating copolymer was prepared by utilizing Fe(phen)3 as the catalyst of the Belousov–Zhabotinsky (BZ) reaction. In this study, 2-acrylamido-2-methylpropane sulfonic acid (AMPS) was newly introduced into the copolymer of N-isopropylacrylamide (NIPAAm) and Fe(phen)3 as the H+providing agent for the BZ reaction. The results indicated that the copolymer solution underwent soluble–insoluble self-oscillation only in malonic acid (MA) and potassium bromate(KBrO3) mixture solution, and the amplitudes were much bigger than those of poly(NIPAAm-co-Fe(phen)3). That is to say, the novel copolymer succeeds in self-oscillating under acid-free conditions. Moreover, the oscillating characteristics were closely related to the content of AMPS in the copolymer.

Phase equilibria of CH4 and CO2 hydrates formed from aqueous solutions of glutaric acid and malonic acid

The equilibrium boundaries of CH4 and CO2 hydrates were examined in the presence of di-carboxylic acids, glutaric acid and malonic acid, at a mass fraction of 0.1 and 0.01. Including di-carboxylic acids in the water phase shifted the phase boundaries to higher pressure and lower temperature conditions. We attributed this to the formation of hydrogen bonding between the inhibitors and water molecules rather than to the formation of water structures serving as hydrate precursors. In addition, the inhibition effect of shorter carbon-chained malonic acid was better than that of longer-chained glutaric acid due to its higher mole fraction in water phase. This inhibition effect was compared with that of conventional thermodynamic hydrate inhibitors (THIs) used in commercial processes. The comparison showed that the effect of malonic acid was close to that of tri-ethylene glycol for inhibiting the CH4 hydrate.

Coarse-Grained Modeling of the Titration and Conductance Behavior of Aqueous Fullerene Hexa Malonic Acid (FHMA) Solutions

The coarse-grained continuum primitive model is developed and used to characterize the titration and electrical conductance behavior of aqueous solutions of fullerene hexa malonic acid (FHMA). The spherical FHMA molecule, a highly charged electrolyte with an absolute valence charge as large as 12, is modeled as a dielectric sphere in Newtonian fluid, and electrostatics are treated numerically at the level of the non-linear Poisson-Boltzmann equation. Transport properties (electrophoretic mobilities and conductances) of the various charge states of FHMA are numerically computed using established numerical algorithms. For reasonable choices of the model parameters, good agreement between experiment (published literature) and modeling is achieved. In order to accomplish this, however, a moderate degree of specific binding of principal counterion and FHMA must be included in the modeling. It should be emphasized, however, that alternative explanations are possible. This comparison is made at 25 °C for both Na(+) and Ca(2+) principal counterions. The model is also used to characterize the different charge states and degree of counterion binding to those charge states as a function of pH.

Highly ordered supermicroporous aluminosilicates with cubic Pm3n symmetry fabricated in weakly acidic solution

Highly ordered supermicroporous aluminosilicates with cubic Pm3n symmetry were prepared for the first time in weakly acidic solutions of succinic acid and malonic acid using dodecyltriethylammonium bromide as a template. The polycarboxylic acids acted as auxiliaries for fabricating the cubic Pm3n structure as well as weak acids. Thermally stable aluminosilicates with a high utilization ratio of Al could be obtained in the presence of succinic acid by either facilely adding aluminum source into the initial synthesis gel or by grinding the as-made silica-surfactant composite with aluminum nitrate. In contrast, thermally stable aluminosilicates could only be prepared via a post-synthesis approach in the presence of malonic acid, probably because of the powerful coordination tendency between malonic acid and Al cations. The thermal stability of the aluminosilicates was enhanced because of the incorporation of Al into the framework or grafting of Al onto the pore walls. Aluminosilicates prepared via the post-synthesis approach preserved the cubic Pm3n structure better than the directly-synthesized ones. In spite of the kind of polycarboxylic acids or the preparation methods, Al was predominantly tetrahedrally coordinated. The aluminosilicates showed a high specific area and pore volume, especially for the post-synthesized ones. The pore size was in the supermicroporous range evidenced by N2 physisorption, though that of the aluminosilicates prepared via the post-synthesis approach was larger. TEM images verified the Pm3n symmetry of the materials herein. The cubic Pm3n aluminosilicates prepared in our research exhibited equal reactivity but a much pronounced deactivation resistance property in the acetalization of cyclohexanone with pentaerythritol.

Comparisons between Hygroscopic Measurements and UNIFAC Model Predictions for Dicarboxylic Organic Aerosol Mixtures

Hygroscopic behavior was measured at 12°C over aqueous bulk solutions containing dicarboxylic acids, using a Baratron pressure transducer. Our experimental measurements of water activity for malonic acid solutions (0–10 mol/kg water) and glutaric acid solutions (0–5 mol/kg water) agreed to within 0.6% and 0.8% of the predictions using Peng’s modified UNIFAC model, respectively (except for the 10 mol/kg water value, which differed by 2%). However, for solutions containing mixtures of malonic/glutaric acids, malonic/succinic acids, and glutaric/succinic acids, the disagreements between the measurements and predictions using the ZSR model or Peng’s modified UNIFAC model are higher than those for the single-component cases. Measurements of the overall water vapor pressure for 50 : 50 molar mixtures of malonic/glutaric acids closely followed that for malonic acid alone. For mixtures of malonic/succinic acids and glutaric/succinic acids, the influence of a constant concentration of succinic acid on water uptake became more significant as the concentration of malonic acid or glutaric acid was increased.

Enrichment of semi-volatile organic acids from aqueous solutions by multiple-effect membrane distillation

Multiple-effect membrane distillation (MEMD) process for enriching semi-volatile organic acids from their individual aqueous solutions was performed by using a hollow fiber-based air gap membrane distillation (AGMD)module with the function of internal heat recovery. Aqueous solutions of glyoxylic acid, glycolic acid, lactic acid, pyruvic acid, malonic acid and glutaric acid were used as model feed. For a feed of 1% (mass fraction), each acid could be enriched for 8–20 times, which depended on the surface tension of the concentrate. The operation performance of MEMD process was characterized by permeation flux J, performance ratio PR and acid rejection rate R. The effects of cold feed-in temperature, heated feed-in temperature, feed-in volumetric flow rate and feed-in concentration on MEMD performance were experimentally evaluated. Maximum values of J, PR and R were 4.8 L/(h·m2), 9.84 and 99.93%, respectively. Moreover, MEMD process demonstrated a fairly good stability in a long-term experiment lasting for 30 d when aqueous solution of 4% (mass fraction) lactic acid was used as a feed.

유기산을 이용한 상수도 정수장 및 배수지 벽면 스케일 세척용 친환경 세정제 개발

본 연구에서는 유기산과 여러 첨가제들을 사용하여 상수도의 정수장이나 배수지 벽면에 침적되어 있는 스케일 제거에 활용할 수 있는 친환경적인 세정제를 개발하고 현장 적용을 수행하였다. 정수장의 벽면의 스케일 분석결과 산화규소(<TEX>$SiO_2$</TEX>), 산화알루미늄(<TEX>$Al_2O_3$</TEX>), 산화철(<TEX>$Fe_2O_3$</TEX>), 산화망간(MnO) 등 주로 금속산화물로 이루어져 있는 것을 알 수 있었다. 그리고 여러 유기산 중에서 말릭산(malic acid), 말론산(malonic acid), 시트릭산(citric acid)과 산화규소를 제외한 산화알루미늄, 산화철, 산화망간 등의 금속산화물에 비교적 좋은 용해력을 보여주었다. 이들 유기산들을 일정 무게비율로 배합하여 산화알루미늄, 산화철, 산화망간의 혼합 금속산화물의 용해력 실험 결과 여러 유기산 배합 비율 중 말릭산, 말론산, 시트릭산이 6 : 2 : 2 배합비율로 만든 10 wt% 유기산 혼합용액이 정수장 및 배수지의 스케일 제거효율이 약 29%로 가장 뛰어났음을 확인할 수 있었다. 이들 유기산 혼합용액에 비이온 계면활성제를 첨가하여 배합한 세정제 용액이 유기산 혼합용액만을 사용한 경우보다 더욱 높은 금속산화물 용해력을 가지는 것을 확인 할 수 있었다. 특히, 알콜에톡실레이트 계열의 LA-7 비이온계면활성제를 0.2% 첨가하는 경우 약 35%의 스케일 제거효율을 보여주었다. 그렇지만 유기산 혼합용액에 살균제를 첨가하는 경우 스케일 제거효율이 저하되었다. 이것은 계면활성제가 오염물의 유화분산 성질에 의해 스케일 제거력 향상에 도움을 주지만 살균제의 경우에는 살균제의 산화력에 의하여 스케일의 물에 대한 용해력을 떨어뜨려 스케일 제거에 방해를 하기 때문인 것으로 판단된다. 이러한 기초실험 결과를 바탕으로 유기산 혼합용액에 첨가제인 계면활성제, 살균제 등을 넣고 배합된 세정제를 사용하여 D시의 상수도 정수장 및 배수지의 스케일 세척시험에 성공적으로 적용시킬 수 있었다. In this study, an environmental-friendly cleaning agent utilizing organic acids and various additives has been developed and applied to the field for removal of scale deposited on the cleaning beds or distribution reservoirs of the waterworks. As an analytical result of scale on the cleaning beds, we found that it consists of mainly metallic oxides such as <TEX>$SiO_2$</TEX>, <TEX>$Al_2O_3$</TEX>, <TEX>$Fe_2O_3$</TEX>, and MnO. Malic acid, malonic acid, and citric acid showed relatively better solvency on <TEX>$Al_2O_3$</TEX>, <TEX>$Fe_2O_3$</TEX>, and MnO except <TEX>$SiO_2$</TEX> among various organic acids. Mixed organic acid solutions of malic acid, malonic acid, and citric acid were prepared with certain weight ratios and their solvencies on mixed metal oxides of <TEX>$Al_2O_3$</TEX>, <TEX>$Fe_2O_3$</TEX>, and MnO were investigated. The experimental results showed that an 10% mixed organic acid solution prepared with weight ratio of malic acid : malonic acid : citric acid = 6 : 2 : 2 were found to have best scale solvency power of about 29%. The formulated cleaning agents with a small amount of nonionic surfactant showed much better solvency on mixed oxides than mixed organic solution alone. Especially, the formulated cleaning agent with 0.2 wt% LA-7 surfactant appeared to have best scale removal efficiency of about 35%. However, the formulated cleaning agent with disinfectants such as NaClO, <TEX>$H_2O_2$</TEX> and <TEX>$Ca(ClO)_2$</TEX> showed poor solvency on mixed oxides. It is inferred that surfactants are able to improve scale removal efficiency due to their capability of emulsification, and disinfectants cause to degrade scale solvency in water because of their oxidation. Based on these basic experimental results, formulated cleaning agents have been prepared with mixed organic acid solution, nonionic surfactants, and disinfectants and successfully applied to removal of scales on the cleaning beds and distribution reservoir at city D waterworks.

The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films

The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films were studied. The voltage–time response for galvanostatic anodization of aluminum in malonic acid solution exhibits a conventional three-stage feature but the formation voltage is much higher. With the increase of electrolyte concentration, the electrolyte viscosity increases simultaneously and the high viscosity decreases the film growth rate. With the concentration increase of the malonic acid electrolyte, the critical current density that initiates local “burning” on the sample surface decreases. For malonic acid anodization, the field-assisted dissolution on the oxide surface is relatively weak and the nucleation of pores is more difficult, which results in greater barrier layer thickness and larger cell dimension. The embryo of the porous structure of anodic film has been created within the linear region of the first transient stage, and the definite porous structure has been established before the end of the first transient stage. The self-ordering behavior of the porous film is influenced by the electrolyte concentration, film thickness and the applied current density. Great current density not only improves the cell arrangement order but also brings about larger cell dimension.

A Facile Fabrication of VO2(A) Micro-nanostructures with Controlled Shape and Its Electrochemical Behavior in Lithium Ion Batteries

Abstract VO2(A) micro-nanostructures have been synthesized via a facile hydrothermal method by hydrolysis of oxidovandium(2+) ethylene glycolate in malonic acid solution. The novel morphologies of VO2(A) could be readily tuned by altering the concentrations of malonic acid and reaction temperature. It is revealed that malonic acid played an important role as a structure directing agent helping the alternative formation of VO2(A). Furthermore, their electrochemical properties were investigated, which reveal that the as-prepared VO2(A) nanorods exhibit a relatively higher first discharge capacity than other VO2(A) morphologies.

Studies on physicochemical characteristics of chitosan derivatives with dicarboxylic acids

Chitosan (N-deacetylated derivative of chitin) was solubilised in different aqueous dicarboxylic acid solutions, including oxalic acid, malonic acid, adipic acid, azelaic acid and also in monocarboxylic acetic acid. These dicarboxylic acid solutions were used with the objective that they not only act as solvents but also enhance material properties of chitosan gel films through chemical cross-linking. The properties including conformational changes of chitosan, chemical interaction, and mechanical, morphological and thermal characteristics of selected chitosan samples studied in this work. The circular dichroism study indicated that the intensity of the broad negative transition of chitosan helical structure in the wavelength region of 190–230 nm decreased with decreasing the chain length of the dicarboxylic acids. The infrared spectra revealed the formation of amide linkage between chitosan and carboxylic acids in solid state. The cross-sections of the films produced from malonic acid and acetic acid solutions of chitosan exhibited granular morphologies with different granule sizes and hill-valley-structures under atomic force microscope. The chitosan/malonic acid film showed improved water resistance and decreased tensile properties compared with the chitosan/acetic acid and chitosan/adipic acid films. These physical characteristics of chitosan/malonic acid film are attributed to the dual effects of malonic acid, which acts as a chemical cross-linker and also as a plasticizer. A strong glass transition (Tg) peak at 166 °C in differential scanning calorimetric analysis was observed, indicating the possible plasticizing effect with malonic acid.

Complexation reactions between lanthanum, gadolinium, and ytterbium and reagents of Arsenazo III group on the surface of fibrous materials loaded with a Chelex 100 ion exchanger

The complex formation reaction between La(III), Gd(III), and Yb(III) with Arsenazo III, Arsenazo M, and Chlorophosphonazo III after adsorption on polyacrylonitrile fiber loaded with an ion exchanger with iminodiacetate groups Chelex 100 has been studied. The influence of medium acidity, duration of the contact of the solution with the adsorbent, the presence of masking agents, and the concentrations of ions on the analytical signals of complexes in the solid phase has been investigated. It has been shown that there is a possibility to perform sorption-spectroscopic determination of the total concentration of the indicated elements using Chlorophosphonazo and the sum of lanthanum and gadolinium with Arsenazo M after adsorption from malonic acid solutions.

The Effects of Coupling Photocatalysis and Sonolysis on Malonic Acid Solution

Sonophotocatalysis of malonic acid solution was carried out in an argon atmosphere. The coupling effects of the combination of photocatalysis and sonolysis were observed. The decomposition rate of malonic acid was improved; that is, the reaction rate for a combined system was higher than the sum of the rates of photocatalysis and sonolysis. Hydrogen peroxide formed from solvent (water) during sonolysis plays an important role for the synergistic effect. A small amount of succinic acid was detected by sonophotocatalysis. It is a characteristic product of the combined system and was not observed for each individual irradiation system. In this process, the carbon numbers of dicarboxylic acid increased from C = 3 (malonic acid) to C = 4 (succinic acid), namely increasing molecular weight or alkyl carbon chain elongation. Therefore, sonophotocatalysis has the potential to make a valuable contribution to organic reactions in water.