Differential Thermal Gravimetry Analysis Research Articles

Novel synthesis of stabilized Bi1–x–yGdxDyyO1.5 solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells (SOFCs)

Herein, we report the synthesis of a Dy–Gd co-doped cubic phase-stabilized Bi2O3 solid electrolyte system via solid-state processing under atmospheric conditions. Doping with Dy3+ and Gd3+ has been observed to significantly enhance the densification process during sintering for stabilization purposes, thereby improving the electrical properties of δ-Bi2O3-type polymorphs. The synthesized ceramics were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM-EDX), thermal gravimetry/differential thermal analysis (TG/DTA), and the four-point probe technique (4PPT). XRD analysis reveals that the samples Bi1–x–yGdxDyyO1.5 (y = 0.05/x = 0.05, 0.10, 0.15, and 0.20, and x = 0.05/y = 0.10, 0.15, and 0.20) exhibit a stable face-centered cubic δ-phase and a mixed-phase crystallographic structure. The XRD analysis of the stabilized δ-phase suggests that the prepared oxides show a face-centered cubic (FCC) structure with a space group of Fm-3m. FESEM micrographs reveal that the composition Bi0.90Gd0.05Dy0.05O1.5 has no significant holes. Nevertheless, an evident increase in the pore formation is observed as the amount of Gd2O3 increases until it reaches 20%. This finding suggests that dense pellets are formed during the sintering process at 900–1000 °C. The DTA analyses were performed to verify the phase stability, which agrees with the XRD results. The electrochemical performance of the synthesized Dy–Gd co-doped Bi2O3 solid electrolyte system was evaluated and analyzed in detail by using the electrochemical impedance spectroscopy (EIS) technique. Based on EIS and conductivity measurements, Bi0.75Gd0.20Dy0.05O1.5 exhibits the lowest activation energy of 0.519 eV and the highest conductivity value of 0.398 S/cm at 627 °C compared to the other samples, this composition can be used as a solid electrolyte for intermediate-temperature solid oxide fuel cells (SOFCs).

Recovery of Valuable Metals from Fly Ash via Hydrometallurgy Method for Li-ion Battery Anode Material

<p>Coal-derived fly ash, or CFA, is a harmful waste for humans. CFA waste handling by its processing and utilization has become the most promising approach, which not only decreases the waste's hazard level but also improves its economic potential. This research aims to recover metals from CFA and utilize them as anode material for Li-ion batteries. Iron, magnesium, aluminum, and calcium are retrieved from the CFA via a two-step hydrometallurgical method, i.e., acid leaching followed by alkaline precipitation. The leaching process utilizes various acids, such as acetic acid (CH<sub>3</sub>COOH), hydrochloric acid (HCl) and sulfuric acid (H<sub>2</sub>SO<sub>4</sub>). Metal precipitation is carried out using sodium hydroxide solution (NaOH). Morphological and quantitative metal composition analysis are investigated using a scanning electron microscope and energy dispersive spectroscopy (SEM-EDX). The physical and chemical properties of the as-prepared samples are characterized using Fourier-transformed Infra-red spectroscopy (FTIR) and Thermal Gravimetry-Differential Thermal Analysis (TG/DTA). Based on the analysis, iron, magnesium and calcium are successfully recovered in a mixed hydroxide precipitate. The type of acid affects the final morphology and composition of the product. Therefore, our approach can be considered effective in CFA waste processing and producing high-quality product.</p>

Development of Galloyl Antioxidant for Dispersed and Bulk Oils through Incorporation of Branched Phytol Chain.

In this study, a novel galloyl phytol antioxidant was developed by incorporating the branched phytol chain with gallic acid through mild Steglich esterification. The evaluation of the radical scavenging activity, lipid oxidation in a liposomal model, and glycerol trioleate revealed its superior antioxidant activities in both dispersed and bulk oils. Then, the antioxidant capacity enhancement of galloyl phytol was further explored using thermal gravimetry/differential thermal analysis (TG/DTA), transmission electron microscopy (TEM), and molecular modeling. The EC50 values of GP, GPa, and GE were 0.256, 0.262, and 0.263 mM, respectively, which exhibited comparable DPPH scavenging activities. These investigations unveiled that the branched aliphatic chain enforced the coiled molecular conformation and the unsaturated double bond in the phytol portion further fixed the coiled conformation, which contributed to a diminished aggregation tendency and enhanced antioxidant activities in dispersed and bulk oils. The remarkable antioxidant performance of galloyl phytol suggested intriguing and non-toxic natural antioxidant applications in the food industry, such as effectively inhibiting the oxidation of oil and improvement of the quality and shelf life of the oil, which would contribute to the use of tea resources and extending the tea industry chain.

Synthesis, Structures, optical properties and DFT studies of neodymium complexes containing octanoyl amino carboxylic acids

Amino acid rare-earth complexes are widely used due to their unique physical and chemical properties. In this study, three kinds of neodymium (III) complexes with octanoyl-aminocarboxylate ligands (abbr. Nd(oct-ala)3, Nd(oct-phe)3, Nd(oct-ser)3) were prepared by a chemical reaction method in methanol as the solvent. The chemical formulas and coordination modes of the neodymium complexes were determined by elemental analysis, 1H NMR and FT-IR. Additional analyses by X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that the neodymium complexes have lamellar irregular shapes and long-range disordered amorphous structures. The thermal performance of the complexes was determined by differential scanning calorimetry (DSC) and thermal gravimetry-differential thermal analysis (TG-DTA). Nd(oct-phe)3 and Nd(oct-ser)3 appeared glassy when heated. The solubility of the complexes in various organic reagents was also measured. The optical properties of the complexes were examined using UV–Vis absorption, polarizing microscopy observations, fluorescence spectra, quantum yield, and fluorescence lifetime. The luminescence properties of the complexes as a function of temperature were further observed by analysis of temperature-dependent emission spectra. The polarizing microscopy observations show that the three neodymium complexes exhibited the characteristic properties of thermotropic liquid crystals. UV–Vis, fluorescence spectroscopy, and quantum yield results show that they have excellent light absorption and luminescence properties. Temperature-dependent emission spectra show that the complexes have good luminescence properties in the temperature range of 25–160 °C. The powdered complexes and the complexed solutions in methanol were irradiated with 380 nm UV light, resulting in blue-violet light emission. A warm white-light device was constructed to further verify the luminescence of the complexes after combining with three kinds of rare-earth complexes (Nd(oct-phe)3, Eu(oct-phe)3, and Tb(oct-phe)3. The color rendering index (CRI) and color temperature (CCT) were measured. In addition, the density functional theory (DFT) was used to determine the geometric structures (Fig S1), and obtain 1H NMR, FT-IR spectra of the neodymium complexes (Fig S2, S3). Their structures were further examined by comparing the calculated with the experimental spectra. The results show that the ligands coordinate to the central Nd3+ through the bidentate chelation mode.

The influence of steam drying process on combustion behavior of Indonesian low-rank coals

Steam drying process of the Low Rank Coals (LRCs) has been conducted to produce coal which is comparable with the High Rank Coal (HRC). Characterization of the raw and dried coals was carried out through proximate, ultimate, calorific value, Fourier Transform Infrared (FTIR) spectroscopy and Thermo Gravimetry-Differential Thermal Analysis (TG-DTA) to study the combustion behavior of the coals. This study used Indonesian low rank coals coming from Tabang (TKK coal) and Samurangau (SP coal), East Kalimantan. The results indicate that the calorific value of the dried coals increases significantly due to the decrease in moisture content of the coal. The FTIR spectrums show that the methylene-ethylene (RCH3/CH2) and aromaticity-aliphaticity ratios (Rar/al) of the dried coals increased while the ratio of RCO/ar decreased which reflect that the rank of the coals increased equivalent to the high rank coal (bituminous). Meanwhile, the TG-DTA indicates that the ignition temperature (Tig) and combustion rate (Rmax) of the dried coals increased. This analysis expresses that the dried coals produced by steam drying process have better combustion behavior due to the higher calorific value than those of the raw coals.

New fabricated electrolytes based on Dy3+-Tm3+ double-doped δ-Bi2O3-type cubic phase

(Bi2O3)1-x-y(Dy2O3)x(Tm2O3)y ternary systems as electrolytes were synthesized at 750 °C by the solid-state ceramic synthesis method. Eight (Bi2O3)1-x-y(Dy2O3)x(Tm2O3)y (x = 0.1, 0.2) and (y = 0.05, 0.1, 0.15, 0.2) electrolytes at different ratios were investigated. The structural, electrical, and thermal properties of these eight electrolytes for solid oxide fuel cells (SOFCs) were characterized by means of a X-ray powder diffractometer (XRD), the four point-probe technique (4PPT), and thermal gravimetry/differential thermal analysis (TG/DTA). Results of XRD measurements showed that the δ-Bi2O3 (cubic) phase with a stable structure was dominantly obtained for all of the samples. As a result of the temperature-dependent electrical measurements of these ternary systems, it was found that electrical conductivity decreases with increasing molar ratio of Tm2O3. The highest electrical conductivity was found for the sample of the (Bi2O3)0.85(Dy2O3)0.10(Tm2O3)0.05 system as 0.349 (Ω cm)−1 at 750 °C. The lowest activation energy was found for the same sample as 0.68 eV.

Structural architectures and biological properties of main group bismuth(III) iodide complexes with heterocyclic thioamides

A series of mononuclear, dinuclear and polynuclear bismuth(III) iodide complexes (1–5) bearing heterocyclic thioamide ligands, 2-mercapto-3,4,5,6-tetrahydro-pyrimidine (tHPMT), 2-mercapto-benzimidazole (MBZIM), 2-mercapto-1-methylimidazole (MMI), 2-mercaptobenzothiazole (MBZT) and 2-mercaptopyridine (PYT), have been synthesized and characterized by melting point, elemental analysis, FT-IR spectroscopy, Raman spectroscopy, 1H, 13C NMR spectroscopy, UV–Vis spectroscopy and Thermal Gravimetry-Differential Thermal Analysis (TG-DTA). Moreover, the crystal structures of 1–5 have been also determined with single crystal X-ray diffraction analysis. The use of the above mentioned heterocyclic thioamide ligands have allowed synthesis of the first examples of bismuth(III) iodide thioamide complexes. {[BiI3(tHPMT)3]} (1) is the first structural example of a neutral mononuclear bismuth(III) iodide complex with octahedral geometry around the bismuth(III) ion with meridional conformation. {[BiI2(µ2-I)(MBZIM)2]2} (2) is the first example of a dinuclear bismuth(III) iodide complex with octahedral geometry around the bismuth(III) ion with trans-S/cis-I arrangement. {[BiI(µ2-I)2(MMI)]n} (3) and {[BiI(µ2-I)2(MBZT)]n·CH3OH} (4) are the first examples of the polynuclear bismuth(III) iodide complexes with octahedral geometry around the bismuth(III) ions. The ligand molecules are coordinated via the thione sulfur atoms in both complexes but in complex 3, ligand molecules are trans to each other in polymeric chain while, in complex 4, ligand molecules are cis to each other in polymeric chain. {[BiI(µ2-S,N-PYT)2]n} (5) is the first example of a polynuclear bismuth(III) iodide complex with pentagonal bipyramidal geometry around the bismuth(III) ions. The seven coordinate bismuth(III) atom has a N2S4I-donor set consisting of one iodine atom and two chelating and bridging μ2-S,N (η2-S:η1-N) pyridine-2-thionate anions.Complexes 1–5 were evaluated for their in vitro cytotoxic activity against human adenocarcinoma cervix (HeLa) and breast (MCF-7) cancer cells. The toxicity of the complexes was studied against human fetal lung fibroblast cells (MRC-5). The influence of 1–5, upon the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX), was evaluated experimentally.

Characterization and hydration of cements and pastes obtained from raw mix containing Moroccan oil shale and coal waste as a raw material

In the present work, the hydration and physical properties of cements obtained from a raw mixes containing oil shale and coal waste as an alternative raw material were explored.A study of clinkers was carried out using chemical analysis and Rietveld analysis and the hydrated products were characterized by conduction calorimetry, X-ray diffraction, FTIR, Differential thermal analysis-thermal gravimetry and Scanning electron microscope. The findings showed that the cement paste containing both oil shale and coal waste had the highest compressive strength.According to the hydration studies, the four hydration steps were observed in all cements. The conduction calorimetry study showed the formation of the calcium monosulfoaluminate phase (AFm) in all cements which in cement containing coal waste was retarded by 50 h due to the high Na2O concentration in its clinker. Further, the identified hydration products: C-S-H gel, portlandite and Afm phase, which detected by XRD, FTIR and ATD/TG have been observed morphologically in SEM images. Moreover, the EDX microstructural study revealed that C-S-H gel contains a less amount of Aluminum and sulfur.

Structural and Temperature Dependent Electrical Conductivity Properties of Dy2O3–Sm2O3 CO-Doped Bi2O3

In the present work, Dy2O3 and Sm2O3 double-doped Bi2O3-based materials are synthesized by exploiting the solid-state synthesis method. The structural and temperature dependent electrical properties of these ternary ceramic samples, which are candidate materials for solid oxide fuel cell (SOFCs) electrolyte, are determined by means of a powder X-ray diffractometer (XRD), the four point-probe method (FPPM), and the thermal-gravimetry/differential thermal analysis (TG/DTA). As a result of the XRD measurements, the fluorite-type fcc δ-phase with a stable structure is obtained for higher values of the dopant oxide material, which are the samples with the maximum content of fixed 20% Dy2O3 and 15% and 20% Sm2O3. The samples with the stable δ-phase structure have higher conductivities. The highest electrical conductivity is found for the (Bi2O3)0.6(Dy2O3)0.2(Sm2O3)0.2 sample, which was 2.5×10–2 (Ohm cm)–1 at 750 °C. The activation energies are also calculated from the Arrhenius charts, which were determined from the FPPM measurements. The lowest activation energy is found as 0.85 eV for the sample with the highest electrical conductivity.

Mineralogical characterization and preliminary assessment of the hydrocarbon potential of sedimentary rock from the western part of the Central Kongo

In this work, the mineralogical characteristics and the assessment of the petroleum potential of organic carbon-rich sedimentary rock (CK sample) originating from the western part of the Central Kongo were the subject of a preliminary analysis and the results were compared with those of Moroccan oil shales. The mineralogical characterization was carried out using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Fourier Transform Infra-Red (FTIR) spectroscopy, Thermal Gravimetry/Differential Thermal Analysis (TG/DTA) and Scanning Electronic Microscopy (SEM-EDX). The results show that the examined sedimentary rock contain a significant part of minerals, about 80%, consisting of quartz, clays and pyrite, similar to those frequently found in oil shales. The pyrolysis also indicates the presence of volatile matter between 250 and 580°C, attributed to the Organic Matter (OM) disseminated within the sedimentary rock as was shown in several carbon-rich materials. The detection of pyrite in the CK sample reveals the existence of a reducing environment during the preservation period of OM in the source rock. The assessment of the petroleum potential using the basic Rock-Eval method associated with the elemental analysis and 13C Cross Polarization/Magic Angle Spinning Nuclear Magnetic Resonance (13C CP/MAS NMR) spectroscopy indicated a very good organic richness (TOC=10.77%), very good petroleum potential (S2=80.4 mgHC/g rock) with the sapropelic OM described as type I kerogen (H/C molar ratio of 1.71) characterized by high hydrogen index (HI=746 mgHC/g TOC) and low oxygen index (OI=13 mgCO2/g TOC) values. The Rock-Eval results were confirmed by 13C CP/MAS NMR spectroscopy which shows the exclusive presence of aliphatics. The mineralogical and petroleum characteristics of CK sample show a great resemblance with those of known oil shales such as Moroccan oil shales and its kerogen is probably related to a marine or lacustrine environment which formed in anoxic sedimentary rocks and with a thermal evolution that has just reached the early stage of the oil window

Synthesis and Luminescence Properties of ZrO2:Gd3+, RE3+(RE = Sm3+ ,Er3+) Phosphors

Abstract In the present study, ZrO2co-doped with Gd3+/Sm3+and Gd3+/Er3+ions have been synthesized using Pechini method. Phase composition, morphology and photoluminescence properties of the synthesized phosphors were investigated by using X-ray powder diffraction (XRD), differential thermal analysis/thermal gravimetry (DTA/TG), scanning electron microscopy (SEM) and photoluminescence spectrofluorometer (PL). After heating at 1200 °C, XRD revealed that the phosphors were crystallized as monoclinic and tetragonal multiphases. SEM images indicated that the phosphors consist of fine and spherical grains with a size around 200 nm to 250 nm. Luminescence studies of these phosphors have been carried out on the emission and excitation, along with lifetime measurements

Compressive strength and microstructure of ordinary cured and autoclaved cement-based composites with mechanically activated kaolins

The effects of two different mechanically activated kaolins, AKV (61% kaolinite, 14% quartz and 16% mica) and AKG (51.6% kaolinite and 40.6% quartz) on the compressive strength of cement composites and microstructure of pastes were investigated. Composite mixtures, in which 10, 20, 30, 40 and 50% of ordinary Portland cement (OPC) was replaced by AKV or AKG, were prepared with w/b of 0.5, and exposed to different curing conditions (ordinary curing for 28 days and autoclaving). Factors affecting microstructure were investigated on pastes by X-ray diffraction (XRD), Differential thermal analysis/thermal gravimetry (DTA/TG) analyses, Mercury intrusion porosimetry (MIP) and Scanning electron microscopy with Energy-dispersive spectroscopy (SEM-EDS).AKG composites exhibited higher compressive strengths under both curing conditions. Positive autoclaving effects on strengths were predominantly pronounced at the higher cement replacement levels. Comparison of the autoclaved and ordinary cured paste microstructure, revealed more intensive pozzolanic reaction during autoclaving conditions (CH content near zero) and higher total porosity. The negative effect of hydrogarnet on the strength was compensated by the formation of the crystalline tobermorite.Obtained results revealed that mechanically activated kaolin, with high content of quartz, could be a promising pozzolanic addition, even at high cement replacement levels (30–50%), especially when autoclaving curing conditions were applied.

Photoluminescence properties of ZrO2:Gd3 +, ZrO2:Gd3 + – Dy3+ and ZrO2:Gd3 + – Yb3+ phosphors by Pechini method

Abstract Zr0.99Gd0.01O2, Zr0.98Gd0.01Dy0.01O2 and Zr0.98Gd0.01Yb0.1O2 phosphors were synthesized by Pechini method at 1200 °C for 12 h in air. The phosphors were characterized by using X-ray powder diffraction (XRD), differential thermal analysis/thermal gravimetry (DTA/TG), scanning electron microscopy (SEM) and photoluminescence spectrofluorometer (PL). X-ray powder diffraction studies showed that the phosphors were crystallized as monoclinic and tetragonal multiphases. The particle size of the phosphors after heat treatment at 1200 °C was found to be of 200 nm to 250 nm. Luminescence studies on these phosphors have been carried out on the emission and excitation, along with lifetime measurements. The results of emission analysis indicate that the phosphors are expected to find potential applications as new optical materials.

Fabrication, characterization, and performance of YbDSB ternary compounds for IT‐SOFC applications

Abstract(Yb2O3)x(Dy2O3)y(Bi2O3)1−x−y (0.04≤x+y≤0.20) powders (xYbyDSB) were synthesized by modified sol‐gel Pecchini method. The powders were characterized for structural, surface morphological, thermal, and electrical properties and power density measurements by means of X‐ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis/thermal gravimetry (DTA/TG), and impedance spectroscopy, respectively. Lattice parameters and crystalline size of δ‐phase of Yb2O3‐ and Dy2O3‐doped Bi2O3 samples were calculated from the X‐ray diffraction data. Surface and grain properties of the related phases were determined by SEM analysis. In the investigated system, the maximum electrical conductivity was observed as σ=0.954 S cm−1 for 6% mol Yb2O3 and 6% mol Dy2O3 at 800°C among all δ‐YbDSB systems. Cathode supported electrochemical cell was fabricated and 6Yb6DSB was used as the electrolyte. Maximum power density of single cell with an active area of 1.5 cm2 is 72.50 mW/cm2 at 700°C.

Study on the addition effect of metakaolin and mechanically activated kaolin on cement strength and microstructure under different curing conditions

The effects of thermally (MK) or mechanically activated kaolin (AK) on the compressive strength of mortars and microstructure of pastes were investigated. Mortar mixtures, in which 10%, 20% and 30% of ordinary Portland cement (OPC) was replaced by either MK or AK, were prepared (w/b of 0.5) and ordinary (age 2, 28 or 90days) and autoclave cured. Hydration products were determined by X-ray diffraction (XRD) and differential thermal analysis/thermal gravimetry (DTA/TG) analysis, while microstructure was investigated by mercury intrusion porosimetry (MIP).MK substitution increases the compressive strength of ordinary-cured mortars, as a result of the higher content of reactive silica that caused more pronounced pozzolanic reaction, as well as by effective refinement of their pore structure. Positive effects on the compressive strength could be achieved up to 30% substitution of OPC by MK. The OPC substitution by AK resulted in lower strengths of ordinary-cured mortars, compared to both MK mortars and reference. Higher specific surface area and finer particles of AK were insufficient to compensate, through filler effect, lower pozzolanic reaction and additional negative influence of the kaolinite presence. The highest compressive strength was obtained for mortar with 10% of AK (relative strength of 94%).In comparison to the reference, autoclaved MK and AK mortars, exhibited lower compressive strength, as a consequence of increasing the hydrogarnet formation, instead of tobermorite. The highest strength was achieved for mortar with 10% of AK.

A Novel Synthesis of Zinc Borates from a Zinc Oxide Precursor via Ultrasonic Irradiation.

In this study, zinc borate hydrate (Zn3B6O12 · 3.5H2O) was synthesized from zinc oxide (ZnO) and boric acid (H3BO3) via a novel method of ultrasonic irradiation. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy were used to characterize the synthesized products. Scanning electron microscopy (SEM) was used to determine the effects of reaction time and reaction temperature on the morphology of the products. Thermal dehydration kinetics were studied using thermal gravimetry and differential thermal gravimetry analysis (TG/DTA). The Doyle and Kissinger non-isothermal kinetic methods were used to analyse the TG/DTA data. The XRD results confirmed the successful synthesis of Zn3B6O12 · 3.5H2O at a range of reaction temperatures and times. Additionally, FT-IR and Raman analysis of the products identified peaks specific to zinc borate. Using the methods of Doyle and Kissinger, the activation energies of thermal dehydration of zinc borate were found to be 341.61 kJ/mol and 390.17 kJ/mol, respectively.

Low-temperature synthesis of titanium oxide/gold nanoparticle composite powders using a combination of the sol–gel process and ultraviolet light irradiation

Amorphous titanium oxide/plasmonic gold nanoparticle composite powders were synthesized by a combination of the sol–gel process and ultraviolet light irradiation using light-emitting diode at room temperature. The resultant composite powders were dried at ~50 °C. These amorphous titanium oxide/gold nanoparticle composite powders were heated to 450 °C to obtain crystalline titanium oxide/gold nanoparticles. The formation and microstructure of the titanium oxide/gold nanoparticle composite powders were confirmed by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermo gravimetry–differential thermal analysis, and optical absorption measurements. A clear plasmonic absorption band due to typical plasmonic gold nanoparticle was observed in both composite powders.

Addition of tetraethylthiuram disulfide to antimony(III) iodide; synthesis, characterization and biological activity

Three new antimony(III) iodide complexes with the N,N-diethylcarbamodithioic acid of formulae {[(SbI(Et2DTC)2)(I2)]n} (1), {[(Sb(Et2DTC)2)4 (SbI6) (I3)]n} (2) and {[SbI(Et2DTC)2]2} (3), (Et2DTCH: N,N-diethylcarbamodithioic acid, C5H11NS2) were synthesized from the reaction of antimony(III) iodide with tetraethylthiuram disulfide in 1:1 stoichiometry. The complexes 1–3 were characterized by melting point, elemental analysis, FT-IR spectroscopy, Raman spectroscopy, 1H, 13C NMR spectroscopy and Thermal Gravimetry–Differential Thermal Analysis (TG–DTA). Moreover, crystal structures of complexes 1–3 were determinated with single crystal X-ray diffraction analysis. Complexes 1–3 derived from ligand reduction with concomitant degradation of the tetraethylthiuram disulfide to dithiocarbamates. Complexes 1 and 2 are polymer but complex 3 is dimmer. Complex 1 consists of two residues, [SbI(Et2DTC)2] and [I2], while 2 consists of three residues, four cationic [Sb(Et2dtc)2]+, one [SbI6]3− and one [I3]− counter anion.Complexes 1–3 were evaluated for their in vitro cytotoxic activity against human breast adenocarcinoma (MCF-7) and human cervix adenocarcinoma (HeLa) cells. Structure Activity Relationship (SAR) studies reveal that the high activity of the complexes is positively correlated with the low H-all atoms intermolecular contacts.

Phase stability and electric conductivity of Eu2O3–Tb4O7 co-doped Bi2O3 electrolyte

In this study, eight different samples of Tb4O7 and Eu2O3 co-doped Bi2O3 were prepared by solid-state synthesis techniques. (Bi2O3)1−x−y(Tb4O7)x(Eu2O3)y (x = 5,10; y = 5, 10, 15, 20 mol%) ternary systems were investigated by using X-ray powder diffraction (XRD), differential thermal analysis/thermal gravimetry (DTA/TG), and four-point probe techniques (4PPT). Effect of concentration of doping elements on the temperature and electrical conductivity was investigated. All samples were evaluated by calculating activation energies and average crystal sizes. XRD measurements show that five samples have a single phase (δ-phase) structure. According to electrical conductivity measurements, the conductivity increases with increasing temperature but decreases with increasing amount of Eu2O3. The highest ionic conductivity was measured as 7.28 × 10−1 (ohm.cm)−1 for the (Bi2O3)0.90(Tb4O7)0.05 (Eu2O3)0.05 sample at 850 °C and the lowest activation energy was measured as 0.64 eV for (Bi2O3)0.90(Tb4O7)0.05 (Eu2O3)0.05.

The Production and Characterization of Ytterbium‐Stabilized Zirconia Films for SOFC Applications

(ZrO2)1–x(Yb2O3)x binary systems were investigated in the doping range of 0.02 ≤ x ≤ 0.12. Ytterbium‐doped zirconia powders were synthesized using the Pechini method. X‐ray diffraction (XRD) measurements showed that fcc ZrO2 was stabilized for 8–12 mol% Yb‐doping rate. The produced Yb‐stabilized Zr (YbSZ) films were characterized; their thickness and homogeneity properties depended on the nature of the YbSZ slurry. All coating parameters were optimized and determined with precoating treatments. The samples were characterized by differential thermal analysis/thermal gravimetry (DTA/TG), scanning electron microscopy (SEM) and ac impedance measurements.