STUDY OF THE INFLUENCE BETWEEN BARIUM IONS AND CALCIUM IONS ON MORPHOLOGY AND SIZE OF COPRECIPITATION IN MICROEMULSION

2015 ◽  
Vol 22 (03) ◽  
pp. 1550036 ◽  
Author(s):  
NONG WANG ◽  
QING LUO MENG
Keyword(s):  
Calcium Carbonate ◽  
Barium Carbonate ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Barium Ions ◽  
Molar Ratios ◽  
Measurement Results ◽  
Inverse Microemulsion ◽  
Barium Ion ◽  
System Phase

In this paper, we systematically drew a series of inverse-microemulsion quasi-ternary system phase diagrams of OP -10+ C 8 H 17 OH + C 6 H 12+ brine  ( CaCl 2/ BaCl 2) by adjusting the ratio of CaCl 2 and BaCl 2. On this basis, microemulsions have been prepared with seven different molar ratios of Ca 2+/ Ba 2+, and calcium carbonate and barium carbonate coprecipitation products were obtained by reaction with an equimolar amount of sodium carbonate. The influence of barium ion to morphology and composition of nanometer calcium carbonate were studied. These samples were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The SEM photographs indicated that when the content of Ca 2+ was higher, some incomplete large cube of coprecipitation particles were formed in solution, but with the content of Ba 2+ increased gradually, they formed a large number of small spherical particles, with the further increase of Ba 2+ concentration, the particles mainly had structures of irregular polyhedron eventually. The measurement results of FTIR and XRD indicated that CaCO 3 coprecipitation products gradually changed from calcite to the vaterite, eventually turned into being aragonite with the further increase of Ba 2+ concentration.

scholarly journals Incorporation of Incompatible Strontium and Barium Ions into Calcite (CaCO3) through Amorphous Calcium Carbonate

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 270 ◽  
Author(s):  
Ayaka Saito ◽  
Hiroyuki Kagi ◽  
Shiho Marugata ◽  
Kazuki Komatsu ◽  
Daisuke Enomoto ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Room Temperature ◽  
Barium Carbonate ◽  
X Ray Diffraction ◽  
Amorphous Calcium Carbonate ◽  
Static Disorder ◽  
Ionic Radii ◽  
Barium Ions ◽  
Alkaline Earth Elements ◽  
Xrd Patterns

Calcite is a ubiquitous mineral in nature. Heavy alkaline-earth elements with large ionic radii such as Sr2+ and Ba2+ are highly incompatible to calcite. Our previous study clarified that incompatible Sr2+ ions can be structurally incorporated into calcite through crystallization from amorphous calcium carbonate (ACC). In this study, we synthesized Sr-doped calcite with Sr/(Sr + Ca) up to 30.7 ± 0.6 mol% and Ba-doped calcite with Ba/(Ba + Ca) up to 68.6 ± 1.8 mol%. The obtained Ba-doped calcite samples with Ba concentration higher than Ca can be interpreted as Ca-containing barium carbonates with the calcite structure which have not existed so far because barium carbonate takes the aragonite structure. X-ray diffraction (XRD) patterns of the Sr-doped and Ba-doped calcite samples obtained at room temperature showed that reflection 113 gradually weakened with increasing Sr/(Sr + Ca) or Ba/(Ba + Ca) ratios. The reflection 113 disappeared at Ba/(Ba + Ca) higher than 26.8 ± 1.6 mol%. Extinction of reflection 113 was reported for pure calcite at temperatures higher than 1240 K, which was attributed to the rotational (dynamic) disorder of CO32− in calcite. Our Molecular Dynamics (MD) simulation on Ba-doped calcite clarified that the CO32− ions in Ba-doped calcites are in the static disorder at room temperature. The CO32− ions are notable tilted and displaced from the equilibrium position of pure calcite.

scholarly journals Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Oxidation Potential ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Optimum Parameters ◽  
Reduction Of Co2 ◽  
Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

scholarly journals Preliminary Study of the Targeted Cleaning of an Artificial Gypsum Layer on White Marble

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Yan Liu ◽  
Taoling Dong ◽  
Kun Zhang ◽  
Fuwei Yang ◽  
Liqin Wang
Keyword(s):  
Electron Microscopy ◽  
Barium Carbonate ◽  
Color Difference ◽  
X Ray Diffraction ◽  
White Marble ◽  
Capillary Suction ◽  
Sulfate Ions ◽  
X Ray ◽  
Preliminary Study ◽  
Scanning Electron

Targeting cleaning of the artificial gypsum layer on white marble was studied. It was conducted by means of the specific depletion of the calcium and sulfate ions by the barium carbonate scavenger, which led to the continuous dissolution and clearance of gypsum layer. The cleaning effect was evaluated by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD), capillary suction, and color difference measurement. By this method, only the gypsum layer was cleared away and the carbonate substrate of marble was left intact at the same time. This method will be highly useful for the conservation of marble relics from surface weathering.

scholarly journals Synthesis, Characterization, Antibacterial Properties, and In Vitro Studies of Selenium and Strontium Co-Substituted Hydroxyapatite

2021 ◽  
Vol 22 (8) ◽  
pp. 4246
Author(s):  
Muhammad Maqbool ◽  
Qaisar Nawaz ◽  
Muhammad Atiq Ur Atiq Ur Rehman ◽  
Mark Cresswell ◽  
Phil Jackson ◽  
...  
Keyword(s):  
Negative Impact ◽  
Antibacterial Properties ◽  
Biological Properties ◽  
Ion Concentration ◽  
Charge Composition ◽  
Bacterial Strains ◽  
X Ray Diffraction ◽  
Molar Ratios ◽  
Human Osteosarcoma Cells

In this study, as a measure to enhance the antimicrobial activity of biomaterials, the selenium ions have been substituted into hydroxyapatite (HA) at different concentration levels. To balance the potential cytotoxic effects of selenite ions (SeO32−) in HA, strontium (Sr2+) was co-substituted at the same concentration. Selenium and strontium-substituted hydroxyapatites (Se-Sr-HA) at equal molar ratios of x Se/(Se + P) and x Sr/(Sr + Ca) at (x = 0, 0.01, 0.03, 0.05, 0.1, and 0.2) were synthesized via the wet precipitation route and sintered at 900 °C. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and cell viability were studied. X-ray diffraction verified the phase purity and confirmed the substitution of selenium and strontium ions. Acellular in vitro bioactivity tests revealed that Se-Sr-HA was highly bioactive compared to pure HA. Se-Sr-HA samples showed excellent antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus carnosus) bacterial strains. In vitro cell–material interaction, using human osteosarcoma cells MG-63 studied by WST-8 assay, showed that Se-HA has a cytotoxic effect; however, the co-substitution of strontium in Se-HA offsets the negative impact of selenium and enhanced the biological properties of HA. Hence, the prepared samples are a suitable choice for antibacterial coatings and bone filler applications.

Structure-Property Relationship of Dodecylbenzenesulfonic Acid Doped Polyaniline

2013 ◽  
Vol 721 ◽  
pp. 199-205 ◽  
Author(s):  
Ying Liu ◽  
Qi Wen ◽  
Jia Li Guan ◽  
Shi Jie Zhao ◽  
Qi Xing Hu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ammonium Persulfate ◽  
Degree Of Crystallinity ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Dodecylbenzenesulfonic Acid ◽  
Molar Ratios ◽  
Liquid Crystal Property ◽  
Relationship Of

Dodecylbenzenesulfonic acid (DBSA) doped polypanilines (PANIs) were chemically synthesized in different molar ratios of aniline (An) to ammonium persulfate (APS) and An to DBSA. The microstructures of these PANIs were investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR). UV-Vis spectrometer, semiconductor parameter analyzer, ubbelohde viscometer and electrospinning technique were used to characterize the optical, electrical properties, viscosity and solubility of these PANIs. The results show that the molar rations of An to APS and An to DBSA had strong effect on the microstructure, molecular weight, degree of crystallinity, optical property, solubility and conductivity of obtained DBSA doped PANI. With the increase of the molar ratios of An to APS and An to DBSA, the conductivities and molecular weight of DBSA doped PANIs decreased, while the degree of crystallinity and solubility of DBSA doped PANIs increased. The DBSA doped PANI could dissolve in dichloromethane or HFIP and could be fabricated short fibers by electrospinning. Moreover, the solution of DBSA doped PANIs in concentrated sulphuric acid showed liquid crystal property.

scholarly journals The Variation Effect of Mg-doped NPs Prepared by Sol-Gel Method on its Structural Properties and Biological Activities

2021 ◽  
Vol 2114 (1) ◽  
pp. 012004
Author(s):  
Duha S. Ahmed ◽  
Noor Q. Ali ◽  
Ali A. Taha
Keyword(s):  
Biological Activities ◽  
Sol Gel ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Nio Nps ◽  
Dopant Element ◽  
Mg Doped

Abstract In this paper, we reported the synthesis of NiO NPs and Mg doped-NiO NPs using the facile sol-gel method. Besides, the influence of the variation of Mg dopant on the structural, morphological and optical properties of the prepared Mg-NiO NPs was studied. The synthesized Mg-NiO NPs nanoparticles were characterized by X-Ray Diffraction Analysis (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), and UV-Vis spectrophotometer. The X-ray diffraction confirmed the formation of the cubic structure of Mg doped-NiO NPs after doping with the magnesium. The increase in the crystal size was observed with the increase in the concentration of the Mg dopant element. The FESEM images reveal the formation of nickel oxide through the appearance of spherical clusters, while the hybrids appear as wrinkled surface covered with spherical particles of magnesium. The UV-Vis spectrum showed a shift towards shorter wavelengths with an increase in the concentration of the Mg dopant element due to the quantum confinement effect. The hemolysis activity study showed that NiO NPs had a low hemolysis percentage of 1.47% and increased with increasing concentration. While, increasing of the RBC hemolysis (5.9%) after NiO doped with Mg. The antibacterial activity was studied against S. aureus and P. aeruginosa bacteria, and indicated the highest growth inhibition zones of Mg-doped NiO NPs as compared with NiO NPs against of Staphylococcus aureus and Pseudomonas aeruginosa, respectively.

scholarly journals Electrochemical synthesis and characterization of BaB6 from molten melt

2009 ◽  
Vol 45 (1) ◽  
pp. 101-109 ◽  
Author(s):  
T.P. Jose ◽  
L. Sundar ◽  
L.J. Berchmans ◽  
A. Visuvasam ◽  
S. Angappan
Keyword(s):  
Molten Salt ◽  
Lithium Fluoride ◽  
Barium Carbonate ◽  
Supporting Electrolyte ◽  
Eutectic Point ◽  
Graphite Crucible ◽  
Electrolytic Cell ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Micron Size

Barium hexaboride (BaB6) crystals were electrochemically synthesized using molten salt technique. Barium carbonate (BaCO3) and boron trioxide (B2O3) was used as reactants. Lithium fluoride (LiF) was used as the supporting electrolyte. The molten electrolyte consisted of 50 wt % BaCO3 and B2O3 with different stiochiometric ratios of Ba and B and 50 wt % lithium fluoride. DTA/TGA studies were made to determine the eutectic point of the melt and it was found to be around 821oC. The electrolytic cell had a high purity graphite crucible, which served as the electrolyte holding vessel and also as the anode for the electrolysis. An electro-polished molybdenum rod was employed as the cathode. The electrolysis was performed at 870?C under argon atmosphere, at current densities ranging from 0.2-0.5 A/cm2. The electrodeposited crystals were examined for the phase identification using X-ray diffraction technique. The AAS and the chemical analysis were made for the determination of chemical composition of the synthesized crystals. The purity of the crystals was also assessed using ICP-MS, XRF and EDX, which reveal that the crystals were associated with trace amount of impurities like oxygen, carbon and iron. The compound is found to be more than 99 % pure. The morphology of the crystals was examined using Scanning Electron Microscopy (SEM). From the above studies, it is concluded that the molten salt process is a simple preparative procedure for the synthesis of sub-micron size barium hexaboride crystals.

The Evaporative Decomposition of Solutions Method (Eds) for the Production of Ultrafine Y1Ba2Cu3O7 from Nitrate and Mixed Anion Precursor Solutions

1989 ◽  
Vol 169 ◽  
Author(s):  
Rollin E. Lakis ◽  
Sidney R. Butler
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Barium Carbonate ◽  
Hollow Spheres ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

AbstractY1Ba2Cu3O7 has been prepared by the evaporative decomposition of solutions method. Nitrate and mixed anion solutions were atomized and decomposed at temperatures ranging from 300°C to 950°C. The resulting materials have been characterized using x-ray powder diffraction, Thermal Gravimetric Analysis (TGA), particle size analysis, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The powder consists of 0.3 micron agglomerated hollow spheres with a primary particle size of 0.06 micron. TGA and x-ray diffraction indicate the presence of barium nitrate and barium carbonate due to incomplete decomposition and/or product contamination by the process environment.

Effects of Rotation Speeds and Media Density on Ground Calcium Carbonate during Ultrafine Grinding Process in Planetary Mill

2014 ◽  
Vol 997 ◽  
pp. 542-545
Author(s):  
Yan Ru Chen ◽  
Yi Chen Lu ◽  
Xiao Min Lian ◽  
Chao Yang Li ◽  
Shui Lin Zheng
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Rotational Speed ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Grinding ◽  
Ultrafine Grinding ◽  
Effects Of Rotation ◽  
Ground Calcium Carbonate

Superfine ground calcium carbonate (GCC) produced by carbonate minerals is a widely used inorganic powder material. In order to get a finer GCC powder with narrow distribution span, the effect of rotational speed and media density on ground GCC were studied by dry grinding GCC in a planetary ball mill under different rotational speed and various media density. The grinding limit-particle size and distribution of grinding calcium carbonate were measured by centrifugal sedimentation granulometer. The structure of GCC was measured by X-ray diffraction. The result shows that low rotational speed and high-density media is conducive to get a product with smaller particle size and narrow size distribution; crystal plane (012) and (122) are more stable than (018) and (116).

Electrochemical Synthesis and Photocatalytic Activity of Differently Shaped CuOx Particles

2017 ◽  
Vol 13 ◽  
pp. 330-333
Author(s):  
Anna Ulyankina ◽  
Igor Leontyev ◽  
Nina Smirnova
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Electrochemical Method ◽  
Spherical Particles ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polyhedral Particles ◽  
Copper Electrodes ◽  
Scanning Electron

CuOx powders with diff erently shaped particles were firstly prepared via an electrochemical method by oxidation and dispersion of copper electrodes in an electrolyte solution under pulse alternating current (PAC). By means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) the current density is found to have an influence on the morphology and composition of CuOx particles. Photocatalytic efficiency of CuOx towards methyl orange (MO) degradation under visible light was investigated. The prepared polyhedral particles show the best photocatalytic activity of 81 % towards MO comparing to octahedral and spherical particles with 70 and 61 %, respectively.

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