Consequences of Fluoride Incorporation on Properties of Apatites

2006 ◽  
Vol 309-311 ◽  
pp. 697-700 ◽  
Author(s):  
Racquel Z. LeGeros ◽  
Dindo Q. Mijares ◽  
Fang Yao ◽  
John P. LeGeros ◽  
T. Bromage ◽  
...  
Keyword(s):  
Crystal Size ◽  
Chemical Properties ◽  
Calcium Deficiency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physico Chemical ◽  
Lower Solubility ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Ft Ir Spectroscopy

Fluoride, when incorporated in the apatite, stabilizes the structure. The purpose of this study was to determine the consequences of fluoride (F) substitution on the physico-chemical properties of apatites. F-containing apatites were prepared by precipitation or by hydrolysis of CaHPO4 in solutions containing different F concentrations and characterized using x-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, thermogravimetry and chemical analyses. Results showed that F incorporation have the following effects: (a) decrease in a-axis dimension, (b) increase in crystal size and thickness, (c) decrease in calcium deficiency, and (d) lower solubility.

scholarly journals Dihydrogen Bonds in Salts of Boron Cluster Anions [BnHn]2− with Protonated Heterocyclic Organic Bases

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 330 ◽  
Author(s):  
Varvara V. Avdeeva ◽  
Anna V. Vologzhanina ◽  
Elena A. Malinina ◽  
Nikolai T. Kuznetsov
Keyword(s):  
Cluster Anions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Boron Cluster ◽  
Organic Bases ◽  
Dihydrogen Bonds ◽  
Reaction Solution ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Ft Ir Spectroscopy

Dihydrogen bonds attract much attention as unconventional hydrogen bonds between strong donors of H-bonding and polyhedral (car)borane cages with delocalized charge density. Salts of closo-borate anions [B10H10]2− and [B12H12]2− with protonated organic ligands 2,2’-dipyridylamine (BPA), 1,10-phenanthroline (Phen), and rhodamine 6G (Rh6G) were selectively synthesized to investigate N−H...H−B intermolecular bonding. It was found that the salts contain monoprotonated and/or diprotonated N-containing cations at different ratios. Protonation of the ligands can be implemented in an acidic medium or in water because of hydrolysis of metal cations resulting in the release of H3O+ cations into the reaction solution. Six novel compounds were characterized by X-ray diffraction and FT-IR spectroscopy. It was found that strong dihydrogen bonds manifest themselves in FT-IR spectra that allows one to use this technique even in the absence of crystallographic data.

scholarly journals Multidimensional Ln-Aminophthalate Photoluminescent Coordination Polymers

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  
Keyword(s):  
Water Content ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Low Cost ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.

Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  
Keyword(s):  
Surface Area ◽  
Sulphuric Acid ◽  
Enzyme Immobilization ◽  
Morphological Changes ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Mineral Oxides ◽  
Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

Hydrothermal synthesis, crystal structure and properties of a two-dimensional uranyl coordination polymer based on a flexible zwitterionic ligand

2018 ◽  
Vol 74 (3) ◽  
pp. 366-371 ◽  
Author(s):  
Wen Cui ◽  
Ruyu Wang ◽  
Xi Shu ◽  
Yu Fan ◽  
Yang Liu ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Hydrothermal Reaction ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Uranyl Compounds ◽  
X Ray ◽  
Potential Applications ◽  
Ft Ir ◽  
Fuel Reprocessing ◽  
Ft Ir Spectroscopy

The interaction between the uranyl cation, (UO2)2+, and organic species is of interest due to the potential applications of the resulting compounds with regard to nuclear waste disposal and nuclear fuel reprocessing. The hydrothermal reaction of various uranyl compounds with flexible zwitterionic 1,1′-[1,4-phenylenebis(methylene)]bis(pyridin-1-ium-4-carboxylate) dihydrochloride (Bpmb·2HCl) in deionized water containing drops of H2SO4resulted in the formation of a novel two-dimensional uranyl coordination polymer, namely poly[tetraoxido{μ2-1,1′-[1,4-phenylenebis(methylene)]bis(pyridin-1-ium-4-carboxylate)}di-μ3-sulfato-diuranium(VI)], [(UO2)2(SO4)2(C20H16N2O4)]n, (1). Single-crystal X-ray diffraction reveals that this coordination polymer exhibits a layered arrangement and the (UO2)2+centre is coordinated by five equatorial O atoms. The structure was further characterized by FT–IR spectroscopy, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). The polymer shows high thermal stability up to 696 K. Furthermore, the photoluminescence properties of (1) has also been studied, showing it to exhibit a typical uranyl fluorescence.

scholarly journals The Bio-fabrication of Gold Nanoparticles (AuNPs) by Green Method and Study of its Electrochemical Applications

2020 ◽  
Vol 1 (4) ◽  
pp. 22-25
Author(s):  
Azwan Morni
Keyword(s):  
Gold Nanoparticles ◽  
Ir Spectroscopy ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Green Method ◽  
Oh Groups ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

This study reports a green method for the synthesis of gold nanoparticles (AuNPs) using the aqueous extract of Salix aegyptiaca extract. The effects of gold salt concentration, extract concentration and extract quantity were investigated on nanoparticles synthesis. Novel methods of ideally synthesizing AuNPs are thus thought that are formed at ambient temperatures, neutral pH, low costs and environmentally friendly fashion. AuNPs were characterized with different techniques such as UV–vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and TEM. FT-IR spectroscopy revealed that gold nanoparticles were functionalized with biomolecules that have primary carbonyl group, -OH groups and other stabilizing functional groups. TEM experiments showed that these nanoparticles are formed with various shapes and X-ray diffraction pattern showed high purity and face centered cubic structure of AuNPs. For electrochemical properties of AuNPs, a modified glassy carbon electrode using AuNPs (AuNPs/GCE) was investigated. The results show that electronic transmission rate between the modified electrode and [Fe (CN)6]3-/4- increased.

Ball-Milling Stimulated Mechanochemical Processes in the System “Titanium-Toluene”

2019 ◽  
Vol 946 ◽  
pp. 351-356 ◽  
Author(s):  
Olga M. Kanunnikova ◽  
V.V. Aksenova ◽  
G.A. Dorofeev
Keyword(s):  
Ball Milling ◽  
Mechanical Energy ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Liquid Phases ◽  
Ft Ir ◽  
Titanium Powders ◽  
Solid Phases ◽  
Ft Ir Spectroscopy

The present work deals with the investigation of the transformations of the solid and liquid phases at high energy planetary ball milling of toluene together with titanium powder. The sequence of structural toluene transformations using FT-IR spectroscopy was investigated. Phase constitutions and morphology of ball milled titanium powders were studied by X-ray diffraction and scanning electron microscopy. It is shown that mechanically induced destruction of toluene occurs by the mechanism of catalytic cracking. During ball milling, concentration of aromatic hydrocarbons in the liquid phase decreases, at the same time the content of alkenes, cycloalkanes, and isoalkanes increases. The main solid products of the mechanosynthesis were cubic and hexagonal titanium carbo-hydrides.Evolution of lattice parameters, crystallites sizes, and micro-stresses of the solid phases during ball milling as a function of the mechanical energy dose have been discussed.

scholarly journals Two-Step Separation of Chitin from Shrimp Shells Using Citric Acid and Deep Eutectic Solvents with the Assistance of Microwave

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 409 ◽  
Author(s):  
Dandan Zhao ◽  
Wen-Can Huang ◽  
Na Guo ◽  
Shuye Zhang ◽  
Changhu Xue ◽  
...  
Keyword(s):  
Citric Acid ◽  
Deep Eutectic Solvents ◽  
Second Step ◽  
X Ray Diffraction ◽  
X Ray ◽  
Shrimp Shells ◽  
Ft Ir ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

In this research, a two-step extraction approach was developed for chitin preparation from shrimp shells by utilizing citric acids and deep eutectic solvents (DESs), which effectively removed minerals and proteins. In the first step, minerals of shrimp shells were removed by citric acid, and the demineralization efficiency reached more than 98%. In the second step, the removal of protein was carried out using deep eutectic solvents with the assistance of microwave, and the deproteinization efficiency was more than 88%. The results of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), and thermogravimetric analysis (TGA) showed that the quality of DES-prepared chitin was comparable to that of traditional acid/alkali-prepared chitin. These results were realized without utilizing hazardous chemicals, which are detrimental to the environment. This research indicates that a DES-based preparation approach has the potential for application in the recovery of biopolymers from natural resources.

scholarly journals Effect of TiO2 Addition on Mortars: Characterization and Photoactivity

2019 ◽  
Vol 9 (13) ◽  
pp. 2598 ◽  
Author(s):  
M. J. Hernández-Rodríguez ◽  
R. Santana Rodríguez ◽  
R. Darias ◽  
O. González Díaz ◽  
J. M. Pérez Luzardo ◽  
...  
Keyword(s):  
Mercury Porosimetry ◽  
Setting Time ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physico Chemical ◽  
Setting Process ◽  
Flow Table ◽  
Negative Effect ◽  
Important Activity

In this study, mortar specimens were prepared with a cement:sand:water ratio of 1:3:0.5, in accordance with standard EN196-1. Portland CEM I 52.5 R grey (G) and white (W) cements were used, together with normalised sand and distilled water. Different amounts of TiO2 photocatalyst were incorporated in the preparation of the mortar samples. The effect of the addition of TiO2 was studied on mechanical properties of the mortar and cement including compressive and flexural strength, consistency (the flow table test), setting time and carbonation. Characterization techniques, including thermogravimetry, mercury porosimetry and X-ray diffraction spectroscopy (XRD), were applied to study the physico-chemical properties of the mortars. It was shown that adding the photocatalyst to the mortar had no negative effect on its properties and could be used to accelerate the setting process. Specimen photoactivity with the incorporated photocatalyst was tested for NOx oxidation in different conditions of humidity (0% RH and 65% RH) and illumination (Vis or Vis/UV), with the results showing an important activity even under Vis radiation.

Two novel organic–inorganic hybrid materials from tetrachloridometallate(II) salts and 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium

2015 ◽  
Vol 71 (1) ◽  
pp. 48-52 ◽  
Author(s):  
José J. Campos-Gaxiola ◽  
Susana P. Arredondo Rea ◽  
Ramón Corral Higuera ◽  
Herbert Höpfl ◽  
Adriana Cruz Enríquez
Keyword(s):  
Three Dimensional ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Pyridinium Cation ◽  
Hydrogen Bonding Interactions ◽  
Dimensional Network ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Two organic–inorganic hybrid compounds have been prepared by the combination of the 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium cation with perhalometallate anions to give 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridocobaltate(II), (C12H12N2)[CoCl4], (I), and 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridozincate(II), (C12H12N2)[ZnCl4], (II). The compounds have been structurally characterized by single-crystal X-ray diffraction analysis, showing the formation of a three-dimensional network throughX—H...ClnM−(X= C, N+;n= 1, 2;M= CoII, ZnII) hydrogen-bonding interactions and π–π stacking interactions. The title compounds were also characterized by FT–IR spectroscopy and thermogravimetric analysis (TGA).

Structure–property relationships in hybrid (C3H5N2)3[Sb2I9] and (C3H5N2)3[Bi2I9] isomorphs

2016 ◽  
Vol 3 (10) ◽  
pp. 1306-1316 ◽  
Author(s):  
M. Węcławik ◽  
A. Gągor ◽  
R. Jakubas ◽  
A. Piecha-Bisiorek ◽  
W. Medycki ◽  
...  
Keyword(s):  
Proton Magnetic Resonance ◽  
Optical Observations ◽  
Structure Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Property Relationships ◽  
Hybrid Crystals ◽  
Ft Ir ◽  
Two Hybrid ◽  
Ft Ir Spectroscopy

Two hybrid crystals imidazolium iodoantimonate(iii) and iodobismuthate(iii) have been synthesized and characterized in a wide temperature range (100–350 K) by means of X-ray diffraction, dielectric spectroscopy, proton magnetic resonance, FT-IR spectroscopy and optical observations.

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