A Comparison of the Role of the Chelating Agent on the Structure of Lithium Conducting Solid Electrolyte Li1.4Al0.4Ti1.6(PO4)3: Pechini vs. Modified Pechini-Type Methods

In recent years, solid lithium-ion conductors have been widely studied because of their applications as electrodes and solid electrolytes in rechargeable lithium-ion batteries. Citric acid (CA) and ethylenediaminetetraacetic acid (EDTA) were employed to synthesize the nanostructured NASICON-type Li1.4Al0.4Ti1.6(PO4)3 ceramic. The chelating agent, together with an ethylene glycol (EG) and the esterification agent were employed to form a network decorated with uniform dispersed metal ions under specific conditions: molar ratio [complexing agent/metal ions] = 1 and the molar ratio [EG/EDTA] = 6, whereas the solution pH was kept below 1. A well crystalline NASICON structure was formed following the heat treatment of the produced gel at 630 °C. Simultaneous thermal analysis (STA) revealed lower required temperature for pyrolysis and crystallization using EDTA. Powder X-ray diffraction (PXRD) showed the formation of larger crystallite size when citric acid was employed. The data from scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) have confirmed the higher apparent porosity and a larger proportion of grain boundaries in the case of EDTA-assisted synthesis.

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Influence of calcium and EDTA on copper ion bioavailability in copper nanoparticle toxicity tests improves understanding of nano-specific effects

Toxicology and Industrial Health ◽

10.1177/0748233720936825 ◽

2020 ◽

Vol 36 (7) ◽

pp. 467-476

Author(s):

Halis Boran

Keyword(s):

Acute Toxicity ◽

Metal Ions ◽

Ethylenediaminetetraacetic Acid ◽

Scale Effects ◽

Copper Ion ◽

Chelating Agent ◽

Aquatic Organisms ◽

Toxicity Tests ◽

Cu Toxicity ◽

Cu Ions

Metal-based nanoparticles (NPs) can release metal ions that are toxic to aquatic organisms; however, whether the toxicity is from metal ions rather than unique “nano-scale” effects of the NPs is unresolved. The present study aimed to compare the toxicity of Cu2+ and Cu-NPs in larval zebrafish ( Danio rerio) to clarify whether toxic effects are attributable to release of Cu ions and to determine the effect of the chelating agent ethylenediaminetetraacetic acid (EDTA) and calcium hardness (as CaCO3) on the Cu toxicity. First, the acute toxicity (96-h lethality) of Cu-NPs was determined in comparison to aqueous Cu in larvae exposed to CuSO4, and subsequently, sublethal tests with Cu-NPs and CuSO4 were conducted with additions of EDTA or calcium ions to evaluate alterations in expression of metallothionein-2 ( MT2) gene transcripts (quantitative real-time polymerase chain reaction). Acute toxicity of Cu in larvae exposed to CuSO4 was greater (LC50 = 226 µg Cu/L) than for larvae exposed to Cu-NPs (LC50 = 648 µg Cu/L). The expression of MT2 increased with Cu concentration ( p < 0.05), and the slope of the linear regression was significantly greater in fish exposed to CuSO4 (slope = 0.090) compared to Cu-NPs (slope = 0.011). Cu2+ was 2.9-fold more toxic than Cu-NPs. The presence of 5 mg/L EDTA and 220 mg/L CaCO3 significantly reduced the expression of MT2 (1.8-fold for EDTA, 2.3-fold for CaCO3) in larvae exposed to CuSO4. For larvae exposed to Cu-NPs, the presence of EDTA reduced the expression of MT2 (1.7-fold) relative to Cu-NP concentration. While Cu-NPs induced MT2 expression, the differences in concentration relationships of MT2 expression between Cu-NPs and CuSO4 indicated that factors other than release of Cu ions from Cu-NPs influenced acute toxicity of Cu-NPs. The conclusion drawn from this ecotoxicological risk assessment was that EDTA and calcium significantly decreased Cu toxicity in freshwater fish.

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Research on Effects of Slurry Additives in Cu CMP for ULSI Manufacturing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.304-305.350 ◽

2006 ◽

Vol 304-305 ◽

pp. 350-354 ◽

Cited By ~ 1

Author(s):

X.J. Li ◽

Dong Ming Guo ◽

R.K. Ren ◽

Zhu Ji Jin

Keyword(s):

Hydrogen Peroxide ◽

Surface Roughness ◽

Electrochemical Impedance Spectroscopy ◽

Citric Acid ◽

Chemical Mechanical Polishing ◽

Electrochemical Impedance ◽

Etching Rate ◽

Complexing Agent ◽

Cu Cmp ◽

Static Etching

In this paper, in order to analyze the oxidation, dissolution and corrosive inhibition effects of additives in the slurry for copper Chemical-mechanical polishing(CMP), the slurry(pH5) with the peroxide as an oxidant, the citric acid as a complexing agent and the benzotriazole(BTA) as an inhibitor is studied. The static etching rate and polishing rate of the Cu-H2O2-Citric acid-BTA slurry are measured. The electrochemical behavior involved in the dissolution and corrosive inhibition of copper in the solutions containing additives is investigated by the electrochemical impedance spectroscopy (EIS) studies. The surface roughness is measured using ZYGO 3-D surface profiler. It is observed that when the slurry is with only 5wt% peroxide existing, copper is stable and slight etching rate on the copper is produced, and the etching rate is only 8.7nm/min. When 0.6wt% citric acid presents after adding 5wt% hydrogen peroxide, the etching rate will increase by 5.3 times, with a blue complexing product emerging. When the inhibitor BTA is added, the corrosion will be effectively restrained. From the EIS results, the impedance of copper in 5wt% peroxide solution which is in passivation can be greatly decreased by adding the citric acid as a complexing reagent. And the impedance of copper in the solution containing peroxide and citric acid can be increased by the addition of BTA. The surface roughness of the wafer polished with the slurry of 5wt% peroxide+0.6wt% citric acid+0.12wt% BTA slurry is Ra 4.7 Å.

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One-Pot Synthesis of Coral-Shaped Gold Nanostructures for Surface-Enhanced Raman Scattering

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.14.47 ◽

2011 ◽

Vol 14 ◽

pp. 47-55 ◽

Cited By ~ 6

Author(s):

Jian Hui Yang ◽

Dhiraj K. Sardar

Keyword(s):

Raman Scattering ◽

Ethylenediaminetetraacetic Acid ◽

Chelating Agent ◽

Surface Enhanced Raman Scattering ◽

Gold Nanostructures ◽

Molar Ratio ◽

One Pot ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Enhanced Raman Scattering

In this work, a chelating agent, ethylenediaminetetraacetic acid (EDTA) was used for the controllable synthesis of gold nanostructures in aqueous solution. Coral-shaped Au nanostructures were synthesized by reducing HAuCl4 with EDTA. EDTA serves not only as a reducing agent but also as a particle capping agent in the formation of coral-shaped Au nanostructures. It is found that the molar ratio of HAuCl4:EDTA and reacted temperature play significant effects on the formation and growth of these novel nanostructures. These Au nanostructures could serve as highly sensitive and reproductive surface-enhanced Raman scattering (SERS) substrates for chemical and biological detection.

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Influence of Molar Ratio of Citric Acid to Metal Ions on Structure, Microstructure and Electrical Transport Properties on Nanosized La0.85Na0.15MnO3

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1107.261 ◽

2015 ◽

Vol 1107 ◽

pp. 261-266

Author(s):

Kean Pah Lim ◽

Kuen Hou Cheong ◽

Abdul Halim Shaari ◽

Mansor Hashim ◽

Albert Han Ming Gan ◽

...

Keyword(s):

Citric Acid ◽

Metal Ions ◽

Grain Boundaries ◽

Transport Properties ◽

Electrical Transport ◽

Perovskite Phase ◽

Hexagonal Structure ◽

Molar Ratio ◽

High Resistivity ◽

Electrical Transport Properties

In this paper, nanosized La0.85Na0.15MnO3 (LNMO) has been synthesized via sol-gel method by involving two major steps, first the complexation of citric acid (CA) with metal ions (MI) and second the polyesterification between CA and ethylene glycol (EG). The effect of molar ratio CA:MI varying from 2-4 on structure, microstructure and electrical transport properties of LNMO have been investigated by constant the amount of EG. All samples show single perovskite phase with hexagonal structure and space group R3c after sintering at 800°C for 10h. Sample of molar ratio 2.5 is observed to possess smallest grain sizes which yield high resistivity value compared with others, is suggested to originate from the increase of tunneling barriers (grain boundaries). The large low field magnetoresistance (LFMR) of about ~ -16% at 0.1T and low temperature confirmed the important role of grain boundaries in the nanosized LNMO.

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Characterization of LiCo Nanopowders Produced by Sol-Gel Processing

Journal of Nanomaterials ◽

10.1155/2010/104012 ◽

2010 ◽

Vol 2010 ◽

pp. 1-8 ◽

Cited By ~ 12

Author(s):

Sina Soltanmohammad ◽

Sirous Asgari

Keyword(s):

Thermal Analyses ◽

Sol Gel ◽

Lithium Ion ◽

Chelating Agent ◽

Complexing Agents ◽

Complexing Agent ◽

Transmission Electron ◽

Sol Gel Process ◽

Size And Morphology ◽

Gel Processing

LiCo nanopowders, one of the most important cathode materials for lithium-ion batteries, were synthesized via a modified sol-gel process assisted with triethanolamine (TEA) as a complexing agent. The influence of three different chelating agents including acrylic acid, citric acid, and oxalic acid on the size and morphology of particles was investigated. Structure and morphology of the synthesized powders were characterized by thermogravimetric/differential thermal analyses (TG/DTA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Results indicate that the powder processed with TEA and calcinated at 800 had an excellent hexagonal ordering of -NaFe-type (space group Rm). Also, the other three complexing agents had a decisive influence on the particle size, shape, morphology, and degree of agglomeration of the resulting oxides. Based on the data presented in this work, it is proposed that the optimized size and distribution of LiCo powders may be achieved through sol-gel processing using TEA as a chelating agent.

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EFFECT OF pH ON THE ELECTRODEPOSITION OF Cu(In, Al)Se2 FROM AQUEOUS SOLUTION IN PRESENCE OF CITRIC ACID AS COMPLEXING AGENT

Surface Review and Letters ◽

10.1142/s0218625x15500572 ◽

2015 ◽

Vol 22 (05) ◽

pp. 1550057 ◽

Cited By ~ 5

Author(s):

YADOLAH GANJKHANLOU ◽

TOURADJ EBADZADEH ◽

MAHMOOD KAZEMZAD ◽

AMIR MAGHSOUDIPOUR ◽

MANSOOR KIANPOUR-RAD

Keyword(s):

Citric Acid ◽

Metal Ions ◽

Spherical Particles ◽

Stable Complex ◽

Complexing Agent ◽

Nanocrystalline Phase ◽

Effect Of Ph ◽

Binary Phase ◽

The One ◽

20 Nm

Effect of pH on the one-step electrodeposition of Cu ( In , Al ) Se 2 chalcopyrite layer in the presence of citric acid has been investigated by applying different electrochemical and characterization techniques. It has been observed that at pH of 1.5, nanocrystalline phase of chalcopyrite and small amount of binary phase of Cu 2 Se with overall composition of Cu 0.91 In 0.32 Al 0.39 Se 2 have been deposited. On the other hand, at pH of 4, the film composition changed to Cu 1.9 In 0.05 Al 0.21 Se 2 and an additional binary phase of copper selenide ( CuSe ) has also been formed. Morphological investigation illustrated that smooth and compact layer with fine spherical particles having the size of ~20 nm has been obtained at pH of 1.5 whereas mixture of planar and spherical particles with size of 450–550 nm have been formed at pH of 4. In alkaline environment (pH~9), the deposition current has been noticeably decreased and no deposition occurred due to the formation of a stable complex of citric acid with metal ions. The mechanism of citric acid interaction with metal ions at different pH has also been studied by cyclic voltammetry measurement.

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Demineralization, Collagen Modification and Remineralization Degree of Human Dentin after EDTA and Citric Acid Treatments

Materials ◽

10.3390/ma12010025 ◽

2018 ◽

Vol 12 (1) ◽

pp. 25 ◽

Cited By ~ 5

Author(s):

Maria Gandolfi ◽

Paola Taddei ◽

Anna Pondrelli ◽

Fausto Zamparini ◽

Carlo Prati ◽

...

Keyword(s):

Citric Acid ◽

Ethylenediaminetetraacetic Acid ◽

Environmental Scanning Electron Microscopy ◽

Chelating Agent ◽

Environmental Scanning ◽

X Ray ◽

Before And After ◽

Human Dentin ◽

Mineral Components ◽

Mineralization Degree

The aim of the study was to investigate the effects of several decalcifying agents used as irrigant solutions in endodontic treatment on collagen and mineral components of dentin. Coronal dentin discs from five caries-free human third molars with a smear layer were treated for one minute with a chelating solution (1% Ethylenediaminetetraacetic acid (EDTA), 10% EDTA, 17% EDTA, 10% citric acid). Mineralization degree (Ca/N and P/N atomic ratios, IR Iapatite/Iamide II and I1410(carbonate)/I554(phosphate) spectroscopic ratios) and possible collagen rearrangements (collagen infrared (IR) amide II e III shifts) were evaluated by environmental scanning electron microscopy (ESEM)/energy dispersive X-ray spectroscopy (EDX) and IR spectroscopy before and after treatment (T0) and after ageing (T24h and T2m) in simulated body fluid (SBF). At T0, analysis showed that the highest demineralizing effect was achieved using a 10% citric acid solution and 10% EDTA, while the smallest effect was observed when using 17% EDTA. No significant collagen modifications were detected upon treatment with 1% EDTA, while subtle changes were observed after the other treatments. At T24h or T2m, analyses showed the highest remineralization values for 1% EDTA and the lowest for 10% citric acid, mainly at T2m. The samples treated with 17% EDTA showed slight collagen rearrangements upon remineralization. In conclusion, the highest demineralizing effect was observed for 10% EDTA and 10% citric acid. Collagen rearrangement was found for all the treatments except for 1% EDTA. The highest remineralization capability in SBF values was recorded for 1% EDTA and the lowest for 10% citric acid. A slight collagen rearrangement upon remineralization was still present in 17% EDTA-treated samples. Clinical use as a chelating agent in the endodontic therapy of citric acid and concentrated EDTA solutions should be reconsidered.

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Enhanced Degradation of Phenol by a Fenton-Like System (Fe/EDTA/H2O2) at Circumneutral pH

Catalysts ◽

10.3390/catal9050474 ◽

2019 ◽

Vol 9 (5) ◽

pp. 474 ◽

Cited By ~ 5

Author(s):

Selamawit Ashagre Messele ◽

Christophe Bengoa ◽

Frank Erich Stüber ◽

Jaume Giralt ◽

Agustí Fortuny ◽

...

Keyword(s):

Chelating Agents ◽

Ethylenediaminetetraacetic Acid ◽

Chelating Agent ◽

Nitrilotriacetic Acid ◽

Molar Ratio ◽

Phenol Removal ◽

Stoichiometric Ratio ◽

Initial Ph ◽

Phenol Conversion ◽

Circumneutral Ph

This work deals with the degradation of phenol based on the classical Fenton process, which is enhanced by the presence of chelating agents. Several iron-chelating agents such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriamine pentaacetic acid (DTPA), and ethylenediamine-N,N’-diacetic acid (EDDA) were explored, although particular attention was given to EDTA. The effect of the molar ligand to iron ratio, EDTA:Fe, initial pH, and temperature on the oxidation process was studied. The results demonstrate that the proposed alternative approach allows the capacity for degrading phenol to be extended from the usual acidic pH (around 3.0) to circumneutral pH range (6.5–7.5). The overall feasibility of the process depends on the concentration of the chelating agent and the initial pH of the solution. The maximum phenol conversion, over 95%, is achieved using a 0.3 to 1 molar ratio of EDTA:Fe, stoichiometric ratio of H2O2 at an initial pH of 7.0, and a temperature of 30 °C after 2 hours of reaction, whereas only 10% of phenol conversion is obtained without EDTA. However, in excess of ligand (EDTA:Fe > 1), the generation of radicals seems to be strongly suppressed. Improvement of the phenol removal efficiency at neutral pH also occurs for the other chelating agents tested.

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Synthesis of Amorphous Al2O3-ZrO2 Powders Prepared by Citric Acid Gel Process

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.73 ◽

2012 ◽

Vol 512-515 ◽

pp. 73-76

Author(s):

Yi Wang ◽

Jia Chen Liu

Keyword(s):

Particle Size ◽

Citric Acid ◽

Thermal Behavior ◽

Metal Ions ◽

Sem Analysis ◽

Molar Ratio ◽

Total Metal ◽

Acid Gel

AmorphousAl2O3ZrO2powders were synthesized by citric acid gel process. The effects of molar ratio of citric acid to total metal ions concentration and the calcined powders with CA/M=2:1 were investigated through XRD and SEM analysis. Thermal behavior of the dried gel with CA/M=2:1 was studied by DSC/TG. Amorphous Al2O3-ZrO2 powders with particle size of about 3μm were obtained.

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