scholarly journals Calcium Sulfate Hemihydrate (Bassanite) Crystals in the Wood of the Tamarix Tree

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 289
Author(s):  
Steve Weiner ◽  
Iddo Pinkas ◽  
Anna Kossoy ◽  
Yishai (Isai) Feldman
Keyword(s):  
Fourier Transform ◽  
Calcium Sulfate ◽  
Calcium Oxalate Monohydrate ◽  
Mineral Phase ◽  
Sem Images ◽  
X Ray ◽  
Elemental Analyses ◽  
Ray Cells ◽  
Sodium And Potassium ◽  
Calcium Sulfate Hemihydrate

The most abundant mineral produced in the wood and leaves of trees is calcium oxalate monohydrate (whewellite), and after burning the wood the ash obtained is calcite. In the case of the Tamarix sp. tree, the freshly prepared ash is calcium sulfate (anhydrite). The aim of this study is to determine the calcium sulfate mineral phase in the fresh wood of Tamarix aphylla prior to burning. SEM images of the crystals show that they express smooth faces, are about 5–15 microns in their longest dimensions and are located in the ray cells. Fourier transform infrared spectroscopy (FTIR) and Raman microspectroscopy of the crystals in the wood and after extraction, both showed that the crystals are composed of calcium sulfate hemihydrate (bassanite). As elemental analyses of the crystals showed that in addition to calcium and sulfur, around 20 atom percent of the cations are sodium and potassium, we also obtained an X-ray powder diffraction pattern. This pattern excluded the possibility that the crystals are composed of another related mineral, and confirmed that, indeed, the crystals in the T. aphylla wood are composed of calcium sulfate hemihydrate (bassanite).

Synthesis and Structural Characterization of a Series of Group 11 2,2-Dialkyl-1,3-dicyclohexylguanidinate Complexes

2014 ◽  
Vol 67 (7) ◽  
pp. 1021 ◽  
Author(s):  
Sonya K. Adas ◽  
Jesus A. Ocana ◽  
Scott D. Bunge
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
7Li Nmr ◽  
Elemental Analyses ◽  
Lithium Diethylamide ◽  
Structural Aspects

The addition of either lithium dimethylamide or lithium diethylamide to a tetrahydrofuran (THF) solution of 1,3-dicyclohexylcarbodiimide yielded THF adducts of lithium 2,2-dimethyl-1,3-dicyclohexylguandidinate (1) and lithium 2,2-diethyl-1,3-dicyclohexylguandidinate (2), respectively. One equivalent of either 1 or 2 was subsequently reacted with one equivalent of Group 11 halide (CuCl, AgBr, and AuCl) to generate oligonuclear complexes with the general formula {M[CyNC(NR2)NCy]}n where M, R, and n are respectively Cu, CH3, 2 (3); Cu, CH2CH3, 2 (4); Ag, CH3, 3 (5); Ag, CH2CH3, 3 (6); Au, CH3, 2 (7); and Au, CH2CH3, 2 (8). Compounds 1–8 were characterized by single-crystal X-ray diffraction. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, Fourier transform infrared spectroscopy, and 1H, 13C, and 7Li NMR studies. The unique structural aspects of this family of Group 11 complexes are highlighted.

scholarly journals Determination of Calcium Sulfate Hemihydrate Modification by X-ray Diffraction Analysis

2016 ◽  
Vol 165 ◽  
pp. 1343-1347 ◽  
Author(s):  
Aleksey Eremin ◽  
Andrey Pustovgar ◽  
Stanislav Pashkevich ◽  
Irina Ivanova ◽  
Anastasiya Golotina
Keyword(s):  
Diffraction Analysis ◽  
Calcium Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Sulfate Hemihydrate

Preparation and Characterization of HAp/TiO2 Nanocomposite for Photocatalytic Degradation of Methyl Orange under UV-Irradiation

2013 ◽  
Vol 829 ◽  
pp. 594-599 ◽  
Author(s):  
Saham Sharifat ◽  
Hossein Zolgharnein ◽  
Abdolghader Hamidifalahi ◽  
Mahnaz Enayati-Jazi ◽  
Entesar Hamid
Keyword(s):  
Fourier Transform ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Uv Irradiation ◽  
Methyl Orange Solution ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Electron Microscopes

A new in-situ precipitation technique is introduced in this study to prepare hydroxyapatite/titania nanocomposites. This technique provides a better control over the microstructures and phase compositions of nanocomposites. The structure and surface morphology of hydroxyapatite/titania nanocomposite were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy and scanning electron microscopes. The photocatalytic activity of hydroxyapatite/titania nanocomposite was evaluated by photocatalytic decolorization of methyl orange in aqueous solution as a model pollutant under UV-irradiation. X-ray diffraction and Fourier transform infrared results indicated that hydroxyapatite and anatase (TiO2) were the major crystalline phases. There had been no reaction between hydroxyapatite and titania compounds. Based on the SEM images, the overall morphology of the samples indicates that there exists a distribution of small particles and large agglomerates.The hydroxyapatite/titania nanocomposite exhibited high photocatalytic activity hydroxyapatite/titania nanocomposite under UV-irradiation. After 8 h of irradiation by UV-irradiation, over 80% of methyl orange solution (5 mg L-1) was decolorized with 1 gL-1 of the photocatalyst. Since this process does not require the addition of hydrogen peroxide and uses UV-irradiation in this study are environmentally friendly method to decolorize azo dye.

Preparation of anhydrite from eggshell via pyrolysis

2018 ◽  
Vol 7 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Nuchnapa Tangboriboon ◽  
Wanitcha Unjan ◽  
Watchara Sangwan ◽  
Anuvat Sirivat
Keyword(s):  
Calcium Sulfate ◽  
Pore Diameter ◽  
Raw Materials ◽  
Raw Material ◽  
X Ray ◽  
Anhydrous Calcium Sulfate ◽  
Calcium Sulfate Dihydrate ◽  
Thermal Analyzer ◽  
Infrared Spectrometer ◽  
Calcium Sulfate Hemihydrate

AbstractCalcium sulfate dihydrate (CaSO4·2H2O) was prepared from the chemical reaction between calcium carbonate from duck eggshell and sulfuric acid at 25°C. The CaSO4·2H2O was dried in an oven at 110°C and transformed into calcium sulfate hemihydrate or plaster of Paris (CaSO4·0.5H2O). The CaSO4·0.5H2O was calcined at 700, 800 and 900°C and transformed into anhydrite or anhydrous calcium sulfate (CaSO4). The raw material used in this research was the duck eggshell, the waste eggshell generated from food processing industries. The obtained anhydrous calcium sulfate or anhydrite has true density, color, specific surface area, pore diameter and particle size equal to 2.95 g/cm3, white powder, 3.57 m2/g, 96.98 Å and 3.983 μm, respectively. In addition, other characteristics, microstructures, phase transformation and physical properties of raw materials and calcium sulfates were investigated and reported here using X-ray fluorescencemeter, Fourier transform infrared spectrometer, differential thermal analyzer, thermogravimetric analysis, scanning electron microscope, X-ray diffractometer, pycnometer method and Brunauer-Emmett-Teller.

scholarly journals A Comparative Performance Evaluation of Some Novel “Green” and Traditional Antiscalants in Calcium Sulfate Scaling

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Konstantin Popov ◽  
Galina Rudakova ◽  
Vladimir Larchenko ◽  
Mariya Tusheva ◽  
Semen Kamagurov ◽  
...  
Keyword(s):  
Calcium Sulfate ◽  
Colloidal Stability ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Comparative Performance ◽  
X Ray ◽  
Acid Sodium Salt ◽  
Blank Experiment ◽  
Efficiency Ranking ◽  
Industrial Samples

A relative ability of industrial samples of four phosphorus-free polymers (polyaspartate (PASP); polyepoxysuccinate (PESA); polyacrylic acid sodium salt (PAAS); copolymer of maleic and acrylic acid (MA-AA)) and of three phosphonates (aminotris(methylenephosphonic acid), ATMP; 1-hydroxyethane-1,1-bis(phosphonic acid), HEDP; phosphonobutane-1,2,4-tricarboxylic acid, PBTC) to inhibit calcium sulfate precipitation is studied following the NACE Standard along with dynamic light scattering (DLS), scanning electron microscopy (SEM), and X-ray diffraction (XRD) technique. For the 0.5 mg·dm−3dosage, the following efficiency ranking was found:MA-AA~ATMP>PESA (400–1500 Da)>PASP (1000–5000 Da)≫PAAS (3000–5000 Da)~PBTC~HEDP. The isolated crystals are identified as gypsum. SEM images for PESA, PASP, PAAS, and HEDP and for a blank sample indicated the needle-like crystal morphology. Surprisingly, the least effective reagent PBTC revealed quite a different behavior, changing the morphology of gypsum crystals to an irregular shape. The DLS experiments exhibited a formation of 300 to 700 nm diameter particles with negativeζ-potential around −2 mV for all reagents.Although suchζ-potential values are not capable of providing colloidal stability, all three phosphonates demonstrate significant gypsum particles stabilization relative to a blank experiment.

scholarly journals Effect of additives on hydration and hardening of magnesia compositions

2018 ◽  
Vol 251 ◽  
pp. 01020
Author(s):  
Olga Miryuk
Keyword(s):  
Calcium Sulfate ◽  
Liquid Density ◽  
Electronic Microscopy ◽  
Dense Structure ◽  
Thermal Methods ◽  
X Ray ◽  
Effect Of Additives ◽  
Magnesium Binding ◽  
Binder Composition ◽  
Calcium Sulfate Hemihydrate

The article is devoted to the investigation of the influence of technological factors on the hydration and hardening of magnesia compositions. The objective – is investigation magnesia compositions with different additives. Factors which impact activity of magnesium oxide in compositions of different structure are investigated. Influence of liquid density on hardening of magnesium bindings is defined. Processes of hydration and hardening of magnesium bindings with participation of minerals – silicates are investigated. It is revealed that the addition of semi-aquatic calcium sulfate contributes to the hardening of magnesia binders. Defined effect of concentration calcium sulfate hemihydrate to the hardening of caustic magnesite. Here are proposed structures of sulphomagnesium compositions containing technogenic components. It revealed a beneficial effect on the hardening of ferrous component of the mixed magnesia binder. Composition of hydration products of magnesium binding with participation of ferriferous minerals is presented. Transformations of phases at hydration of magnesium binding are revealed. Influence of structure of bindings on transformations of hydrates is established. Results of research of magnesia bindings of long hardening are given. It is shown that the durability of stone of bindings is provided with dense structure of hydrates. In researches are used X – Ray and thermal methods, electronic microscopy.

Characterization of Gypsum Waste from Civil Construction to Obtain Polymer Composites

2019 ◽  
Vol 958 ◽  
pp. 47-51
Author(s):  
Suellen Signer Bartolomei ◽  
Helio Wiebeck
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Polymer Composites ◽  
Ball Mill ◽  
Calcium Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Hydrated Calcium

This work aims to characterize the post-consumption plaster and compare it with virgin plaster. Burrs from plaster frames manufacturing were collected at the manufacturer. These samples were dried in a drying oven. Then, they were milled in a ball mill, until forming a fine and homogeneous powder. The samples were returned to the drying oven at three different temperatures, 100, 150 and 200°C, to define the best drying temperature, because the water removed in this process changes the structure of the semi-hydrated calcium sulfate gypsum into bihydrated. Then, vibrational Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were performed to characterize the virgin plaster and the reused plaster, making it possible to know the structure and the groups present in the components.

scholarly journals Chromium (III) Oxide Nanostructures Synthesized from Vernonia Amygdalina Leaves Extract

2020 ◽  
Vol 10 (1) ◽  
pp. 1856-1861
Keyword(s):  
Fourier Transform ◽  
Average Crystallite Size ◽  
Fourier Transform Infrared ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Vernonia Amygdalina ◽  
Sem Images ◽  
X Ray ◽  
Chloride Hexahydrate ◽  
Diffraction Patterns

This contribution reports first time synthesis of Cr2O3 nanostructures from chromium (III) chloride hexahydrate precursor using Vernonia amygdalina leaves extract as a reducing and stabilizing agent. Powder X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy techniques were used to study the structural and morphological properties of the as-synthesized Cr2O3 nanostructures. Powder X-ray diffraction patterns spectral analysis showed that hexagonal Cr2O3 nanostructures with an average crystallite size of 23.4 nm were synthesized with the minor appearance of CrO2. SEM images showed that the synthesized nanomaterials are granules. Fourier-transform infrared spectra represent a sharp absorption band at 552 cm-1, which indicates Cr-O-Cr vibrational and stretching modes.

Nanofiber Polyaniline and Polyaniline-Clay Nanocomposite Prepared via Sonochemical and Sol-Gel Techniques

2016 ◽  
Vol 860 ◽  
pp. 12-16 ◽  
Author(s):  
Amira Abdelraheem ◽  
Ahmed H. El-Shazly ◽  
M.F. El-Kady
Keyword(s):  
Molecular Structure ◽  
Fourier Transform ◽  
Sol Gel ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Gel Preparation ◽  
Preparation Techniques ◽  
Composite Samples

Polyaniline (PANI) and polyaniline-clay (PANI-clay) composite nanostructured materials were prepared via both ultrasonic irradiation and sol-gel preparation techniques. The molecular structure of prepared PANI and PANI-clay composite samples were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The characterization results confirm the nanostructure of prepared samples. BET surface area results were obtained for the prepared matrices. TEM and SEM images showed the morphology of the fabricated nanomaterials.

Accelerated and Retarded Dental Plaster Setting Investigated by X-Ray Diffraction

1970 ◽  
Vol 49 (3) ◽  
pp. 502-507 ◽  
Author(s):  
J.K. Harcourt ◽  
E.P. Lautenschlager
Keyword(s):  
Calcium Sulfate ◽  
Continuous Monitoring ◽  
Product Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Setting Times ◽  
Diffraction Peaks ◽  
Dental Plaster ◽  
Kinetics Of ◽  
Calcium Sulfate Hemihydrate

Continuous monitoring of calcium sulfate hemihydrate and dihydrate X-ray diffraction peaks was done to determine the kinetics of gypsum-product formation during the setting of plaster mixtures containing various concentrations of accelerators and retarders. Amounts of product formation were then correlated to Gillmore setting times and to compressive strengths.

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