Crystal structure, thermal crystal form transformation, desolvation process and desolvation kinetics of two novel solvates of ciclesonide

RSC Advances ◽  
2016 ◽  
Vol 6 (56) ◽  
pp. 51037-51045 ◽  
Author(s):  
Lina Zhou ◽  
Qiuxiang Yin ◽  
Shichao Du ◽  
Hongxun Hao ◽  
Yanfeng Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Analytical Techniques ◽  
Crystal Form ◽  
Form Transformation ◽  
Kinetics Of

Two novel solvates of ciclesonide were successfully obtained and characterized by various analytical techniques (XRPD, XRSD, DSC, TGA and HSM). Thermal crystal form transformation and desolvation process of the solvates were also studied.

Crystal structure and thermal decomposition kinetics of a 2D coordination polymer of cadmium(II)

2008 ◽  
Vol 61 (20) ◽  
pp. 3237-3244 ◽  
Author(s):  
Ying-Xia Zhou ◽  
Si-Yin Liu ◽  
Xiao-Qing Shen ◽  
Hong-Yun Zhang ◽  
Ya-Hui Yu
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Coordination Polymer ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Kinetics Of

scholarly journals Green Synthesis of Zinc Nanoparticles Using Aqueous Extract of Magnoliae officinalis and Assessment of its Bioactivity Potentials

2020 ◽  
Vol 11 (1) ◽  
pp. 7765-7774
Keyword(s):  
Antibacterial Activity ◽  
Zeta Potential ◽  
Aqueous Extract ◽  
Analytical Techniques ◽  
Crystal Form ◽  
Biological Properties ◽  
Synthesis Process ◽  
Diffusion Method ◽  
Zno Nps ◽  
Zinc Nanoparticles

Today, considerable attention has been drawn to the unique physicochemical and biological properties of zinc nanoparticles. In this study, ZnO-NPs were synthesized using Magnoliae officinalis (MO) aqueous extract as a reducing and capping agent. Characteristics of ZnO-NPs were analyzed using analytical techniques such as UV, FTIR, SEM, XRD, EDX, DLS, and zeta potential. After that, the antibacterial activity of ZnO-NPs against methicilin resistant Staphylococcus aureus (MRSA) was studied. The results of FTIR and UV-vis spectra showed successful biosynthesis of ZnO-NPs, because the absorption peaks and functional groups involved in the synthesis process were well developed. Additionally, the SEM micrograph and the DLS showed that the morphology and size distribution of the ZnO-NPs were spherical with a size of 150 nm. XRD, EDX, and zeta potential indicated crystal form of ZnO-NPs with zinc: oxygen ratio of 72.35:27 and a surface charge of +28 mv. The antibacterial activity of ZnO-NPs with the assessment of the well-diffusion method, MIC and MBC indicated the highest inhibitory effect at a concentration of 300 µg/ml, MIC 250 µg/ml and MBC 300 µg/ml. As regards the desirable antimicrobial activity of biosynthesized ZnO-NPs using MO extract, they may be used for medicinal purposes, in particular as antimicrobials and antiseptic agents.

scholarly journals Non-Isothermal Sublimation Kinetics of 2,4,6-Trinitrotoluene (TNT) Nanofilms

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1163 ◽  
Author(s):  
Walid Hikal ◽  
Brandon Weeks
Keyword(s):  
Activation Energy ◽  
Analytical Techniques ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Absorbance Spectroscopy ◽  
Calculated Activation Energy ◽  
Sublimation Kinetics ◽  
Sublimation Rates ◽  
First Time ◽  
Kinetics Of

Non-isothermal sublimation kinetics of low-volatile materials is more favorable over isothermal data when time is a crucial factor to be considered, especially in the subject of detecting explosives. In this article, we report on the in-situ measurements of the sublimation activation energy for 2,4,6-trinitrotoluene (TNT) continuous nanofilms in air using rising-temperature UV-Vis absorbance spectroscopy at different heating rates. The TNT films were prepared by the spin coating deposition technique. For the first time, the most widely used procedure to determine sublimation rates using thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) was followed in this work using UV-Vis absorbance spectroscopy. The sublimation kinetics were analyzed using three well-established calculating techniques. The non-isothermal based activation energy values using the Ozawa, Flynn–Wall, and Kissinger models were 105.9 ± 1.4 kJ mol−1, 102.1 ± 2.7 kJ mol−1, and 105.8 ± 1.6 kJ mol−1, respectively. The calculated activation energy agreed well with our previously reported isothermally-measured value for TNT nanofilms using UV-Vis absorbance spectroscopy. The results show that the well-established non-isothermal analytical techniques can be successfully applied at a nanoscale to determine sublimation kinetics using absorbance spectroscopy.

scholarly journals Effect of pressure on the crystal structure of L-serine-I and the crystal structure of L-serine-II at 5.4 GPa

2005 ◽  
Vol 61 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Stephen A. Moggach ◽  
David R. Allan ◽  
Carole A. Morrison ◽  
Simon Parsons ◽  
Lindsay Sawyer
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Ambient Pressure ◽  
Crystal Form ◽  
Hydroxyl Groups ◽  
Orthorhombic Space Group ◽  
Crystal Forms ◽  
Hydrogen Bonded

The crystal structure of L-serine has been determined at room temperature at pressures between 0.3 and 4.8 GPa. The structure of this phase (hereafter termed L-serine-I), which consists of the molecules in their zwitterionic tautomer, is orthorhombic, space group P212121. The least compressible cell dimension (c), corresponds to chains of head-to-tail NH...carboxylate hydrogen bonds. The most compressible direction is along b, and the pressure-induced distortion in this direction takes the form of closing up voids in the middle of R-type hydrogen-bonded ring motifs. This occurs by a change in the geometry of hydrogen-bonded chains connecting the hydroxyl groups of the —CH2OH side chains. These hydrogen bonds are the longest conventional hydrogen bonds in the system at ambient pressure, having an O...O separation of 2.918 (4) Å and an O...O...O angle of 148.5 (2)°; at 4.8 GPa these parameters are 2.781 (11) and 158.5 (7)°. Elsewhere in the structure one NH...O interaction reaches an N...O separation of 2.691 (13) Å at 4.8 GPa. This is amongst the shortest of this type of interaction to have been observed in an amino acid crystal structure. Above 4.8 GPa the structure undergoes a single-crystal-to-single-crystal phase transition to a hitherto uncharacterized polymorph, which we designate L-serine-II. The OH...OH hydrogen-bonded chains of L-serine-I are replaced in L-serine-II by shorter OH...carboxyl interactions, which have an O...O separation of 2.62 (2) Å. This phase transition occurs via a change from a gauche to an anti conformation of the OH group, and a change in the NCαCO torsion angle from −178.1 (2)° at 4.8 GPa to −156.3 (10)° at 5.4 GPa. Thus, the same topology appears in both crystal forms, which explains why it occurs from one single-crystal form to another. The transition to L-serine-II is also characterized by the closing-up of voids which occur in the centres of other R-type motifs elsewhere in the structure. There is a marked increase in CH...O hydrogen bonding in both phases relative to L-serine-I at ambient pressure.

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