scholarly journals Stabilising peroxyacids in niche microenvironments

2014 ◽  
Vol 70 (a1) ◽  
pp. C644-C644
Author(s):  
Dyanne Cruickshank ◽  
Chick Wilson
Keyword(s):  
Chemical Reactivity ◽  
Analytical Techniques ◽  
Direct Consequence ◽  
High Reactivity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Wide Range ◽  
Chemically Reactive Species ◽  
Household Cleaning Products

There has been dramatic evolution in the formulation of household cleaning products over the last decade, this is mainly due to the influence of social change, regulatory pressure and the need for new less toxic, safer formulations with increased performance. Due to their high chemical reactivity, peroxides are found in a wide range of bleaching agents, they are known for their instability which is a direct consequence of their high reactivity (in turn essential for function). Stabilising such materials for implementation in a range of product types is a significant target within the domestic products industry. Supramolecular approaches are already being explored to try stabilise other chemically reactive species such as explosives [1,2] thus illustrating the feasibility of this research. The work to be presented will deal with peroxyacids that include small model compounds such as m-chloroperbenzoic acid as well as a commericially relevant bleaching agent and their inclusion in both crystalline and amorphous hosting systems. Single crystal X-ray diffraction methods are used to elucidate the ordered crystalline structures and to confirm whether or not the peroxo group is still intact within the crystalline host environments. Simple reactivity tests are used to demonstrate whether or not the amorphous host-guest complexes contain the active peroxy acid within their host cavity. Other complementary analytical techniques such as powder X-ray diffraction, differential scanning calorimetry and thermogravimetry have also been used to characterise the newly-hosted peroxyacid materials. By hosting these molecules in microenvironments it is possible to prepare formulations that are less pH sensitive, thus making their storage safer while allowing their reactivity to be controlled and tuned.

scholarly journals High Throughput Screening and Characterization Methods of Jordanian Oil Shale as a Case Study

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3148 ◽  
Author(s):  
Ziad Abu El-Rub ◽  
Joanna Kujawa ◽  
Esra’a Albarahmieh ◽  
Nafisah Al-Rifai ◽  
Fathieh Qaimari ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Oil Shale ◽  
Analytical Techniques ◽  
Economic Feasibility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Characterization Methods ◽  
X Ray ◽  
Hydrogen Mass

Oil shale is an important possible solution to the problem of energy in Jordan. To explore the technical and the economic feasibility of oil shale deposits, numerous samples are analyzed using the standard Fischer Assay (FA) method. However, it would be useful to develop faster, cheaper, and reliable methods for determining the oil content of oil shale. Therefore, the aim of this work was to propose and investigate rapid analytical techniques for the screening of oil shale deposits and to correlate them with the FA method. The Omari deposit located east of Jordan was selected as a case study for analysis using thermogravimetric analysis (TGA) coupled with Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), elemental analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. Results obtained from the TGA method were linearly correlated with FA with high regression factor (R2 = 0.99); a quadratic correlation (R2 = 0.98) was maintained between the FA and the elemental hydrogen mass content, and a quadratic correlation (R2 = 0.97) was found between the FA and the aliphatic hydrocarbons (FTIR peak at 2927 cm−1) produced in the pyrolysis zone. Although other techniques were less correlated, further investigation might lead to better results. Subsequently, these correlated techniques can be a practical alternative to the conventional FA method when, in particular, specific correlation is made for each deposit.

Investigation of (micro-)meteoritic materials at the new hard X-ray imaging PUMA beamline for heritage sciences

2019 ◽  
Vol 26 (6) ◽  
pp. 2033-2039 ◽  
Author(s):  
Pieter Tack ◽  
Benjamin Bazi ◽  
Bart Vekemans ◽  
Tulin Okbinoglu ◽  
Flore Van Maldeghem ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Contrast Imaging ◽  
X Ray ◽  
High Profile ◽  
Imaging Tool ◽  
X Ray Imaging ◽  
Synchrotron Facility ◽  
Wide Range ◽  
New Instrument

At the French synchrotron facility SOLEIL, a new X-ray imaging facility PUMA (Photons Utilisés pour les Matériaux Anciens) has been made available to scientific communities studying materials from cultural heritage. This new instrument aims to achieve 2D and 3D imaging with microscopic resolution, applying different analytical techniques including X-ray fluorescence spectroscopy (XRF), X-ray absorption spectroscopy (XAS), X-ray diffraction and phase-contrast imaging. In order to discover its capabilities a detailed analytical characterization of this beamline as an analytical and imaging tool is deemed necessary. In this work, (confocal) XRF and XAS analyses are demonstrated using the Seymchan pallasite meteorite and an Antarctic unmelted micrometeorite as case studies. The obtained spatial resolution (2 µm × 3 µm) and sensitivity (detection limits <10 p.p.m. for 1 s acquisition at 18 keV) show that PUMA is a competitive state-of-the-art beamline, providing several high-profile and high-in-demand analytical methods while maintaining applicability towards a wide range of heritage-oriented sciences.

Characterization of the Aurivillius Type PbBi4Ti4O15 Piezoelectric Ceramic Doped with Eu3+

2006 ◽  
Vol 45 ◽  
pp. 2483-2488
Author(s):  
L. Pablos ◽  
Maria Elena Villafuerte-Castrejón ◽  
A. Ibarra-Palos ◽  
J. Ocotlán-Flores ◽  
R. Sato ◽  
...  
Keyword(s):  
Piezoelectric Ceramic ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
Layered Oxides ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Density Measurements ◽  
X Ray ◽  
Wide Range

PbBi4Ti4O15 belongs to the bismuth oxide layers family discovered by Aurivillius more than 50 years ago. In the last few years, there has been considerable interest in layered oxides exhibiting ferroelectric, piezoelectric and other related properties due to their wide range of application in technical devices. In the present work the PbBi4Ti4O15 solid solution formed with Eu3+ was synthesized by coprecipitation method and solubility limit was found. All compounds were characterized by scanning electron microscopy, density measurements and X-ray diffraction. The variation of lattice parameter with the Eu3+ concentration was obtained. Raman spectroscopy was carried out in order to determine the Eu3+ site in the lattice. Thermal analysis (thermogravimetry and differencial scanning calorimetry) results are also presented.

scholarly journals Toward an Understanding of the Formation and Desolvation of Methanol Solvate, and Structure of Methanolysis Product: A Case Study of Nicosulfuron

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 157
Author(s):  
Huaxiang Zhu ◽  
Bei Zhang ◽  
Di Wu ◽  
Xiaowei Cheng ◽  
Guiping Li ◽  
...  
Keyword(s):  
Solid Phase ◽  
Great Influence ◽  
Acid Methyl Ester ◽  
Analytical Techniques ◽  
Systematic Investigation ◽  
Herbicidal Activity ◽  
Carbamic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Nicosulfuron (NS) is a widely used sulfonylurea herbicide because of its high selectivity, broad spectrum of herbicide activity, and excellent performance. In this work, nicosulfuron methanol solvate (NS-MeOH) and [[3-[(Dimethylamino)carbonyl]-2-pyridinyl]sulfonyl]carbamic acid methyl ester (PCM) as a product of methanolysis of NS were obtained. Both of their structures were determined by a single crystal X-ray diffraction. A broad range of analytical techniques was applied to characterize the NS-MeOH, such as Powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and hot stage microscopy (HSM). Combined with the analysis of the Independent gradient model (IGM), Atom-in-molecules (AIM), and Hirshfeld surface (HS), direct insights into the role of solvent played in the formation of NS-MeOH and the mechanism of solid-to-solid phase transformation of NS-MeOH could be obtained. In addition, the aqueous solubility of NS was improved through the formation of NS-MeOH. A systematic investigation of herbicidal activity of NS and PCM was carried out. It was found that NS and NS-MeOH had similar herbicidal activities at the experimental concentrations while PCM exhibited significantly lower activity. It was suggested that methanolysis of the sulfonylurea bridge in the NS molecule exerted a great influence on the herbicidal activity.

scholarly journals Structural studies of crystalline forms of triamterene with carboxylic acid, GRAS and API molecules

IUCrJ ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 309-324 ◽  
Author(s):  
Abida Rehman ◽  
Amit Delori ◽  
David S. Hughes ◽  
William Jones
Keyword(s):  
Analytical Techniques ◽  
Gravimetric Analysis ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Evaporative Crystallization ◽  
Structural Database ◽  
Crystalline Forms ◽  
Good Agreement

Pharmaceutical salt solvates (dimethyl sulfoxide, DMSO) of the drug triamterene with the coformers acetic, succinic, adipic, pimelic, azelaic and nicotinic acid and ibuprofen are prepared by liquid-assisted grinding and solvent-evaporative crystallization. The modified ΔpK a rule as proposed by Cruz-Cabeza [(2012). CrystEngComm, 14, 6362–6365] is in close agreement with the results of this study. All adducts were characterized by X-ray diffraction and thermal analytical techniques, including single-crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry and thermal gravimetric analysis. Hydrogen-bonded motifs combined to form a variety of extended tapes and sheets. Analysis of the crystal structures showed that all adducts existed as salt solvates and contained the aminopyridinium–carboxylate heterodimer, except for the solvate containing triamterene, ibuprofen and DMSO, as a result of the presence of a strong and stable hemitriamterenium duplex. A search of the Cambridge Structural Database (CSD 5.36, Version 1.18) to determine the frequency of occurrence of the putative supramolecular synthons found in this study showed good agreement with previous work.

scholarly journals Synthesis of Polytetrahydrofuran Using Protonated Kaolin as A Solid Acid Catalyst

2019 ◽  
Vol 14 (2) ◽  
pp. 294
Author(s):  
Abdelhak Moumen ◽  
Zhour Hattab ◽  
Youghourta Belhocine ◽  
Kamel Guerfi ◽  
Nacer Rebbani
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Analytical Techniques ◽  
Acid Catalyst ◽  
Crystalline Substance ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

In this work, a non-toxic protonated kaolin clay exchanged with protons, was successfully applied as a solid acid catalyst for the polymerization of tetrahydrofuran (poly(THF)) at room temperature in the presence of acetic anhydride. Prior to using the kaolin as a catalyst, it was treated with HCl (0.1 M) and characterized using various analytical techniques. The amounts of catalyst and reaction time on the conversion of THF were investigated. Characterizations of nuclear magnetic Resonance of proton (1H-NMR), Fourier Transform Infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), Optical Microscopy (OM), and Differential Scanning Calorimetry (DSC) techniques were used to examine the resulting polymer. X-ray characterization and DSC data indicated that the obtained poly(THF) is a highly crystalline substance. The results showed that protonated kaolin (kaolin–H+) has a high catalytic activity for the polymerization of THF with a conversion rate of 50.02% after 20 hours. Copyright © 2019 BCREC Group. All rights reserved. 

scholarly journals Structural, Morphological and thermal properties of Nano filler Produced from Date Palm-based Micro Fibers (Phoenix Dactylifera L.)

2021 ◽  
Author(s):  
Othman Y Alothman ◽  
H.M. Shaikh ◽  
Basheer A. Alshammari ◽  
Mohammad Jawaid
Keyword(s):  
Electron Microscopy ◽  
Date Palm ◽  
Low Cost ◽  
Analytical Techniques ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Green Composite ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Wide Range

Abstract In this century, the development of nano-sized filler from biomass material has become the main focus of industries in achieving their final green composite product for wide range of applications. From commercial and environmental point of view, fragmentation and downsizing of waste lignocellulosic fibers without chemical treatments into small size particles is a viable option. In this study, an attempt was made to produce nano-sized lignocellulosic fillers from date palm micro fibers via simple mechanical ball milling process. The resultant nanofillers as well as the microfibers were characterized in details by various analytical techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), particle size analysis (PSA), Energy Dispersive X-Ray (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to assess their structure­—property relationship. From microscopy examination, the nanofillers showed a heterogeneous mix of irregular shaped particles, and while having a size ranging of 30-110 nm in width and 1-10 mm length dimensions. Also, the crystallography analysis revealed the crystallinity had mildly declined from microfibers (71.8%) to nanofiller (68.9%) due to amorphization effect. As for thermal analysis, the nanofillers exhibited relatively stable in both heat resistance and thermos changing behavior, suggesting its suitability for composite fabrication process at high temperature. Thus, the produced nanofillers can be used as a low cost reinforcing agent in the future for versatile polymer-based composite systems.

Structure of lithium tellurite and vanadium lithium tellurite glasses by high-energy X-ray and neutron diffraction

2021 ◽  
Vol 77 (2) ◽  
Author(s):  
Hirdesh ◽  
Atul Khanna ◽  
Margit Fábián ◽  
Ann-Christin Dippel ◽  
Olof Gotowski
Keyword(s):  
Neutron Diffraction ◽  
Glass Network ◽  
High Energy ◽  
Coordination Shell ◽  
Tellurite Glasses ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Factors ◽  
Wide Range

xLi2O–(100 − x)TeO2 (x = 20 and 25 mol%) and xV2O5–(25 − x)Li2O–75TeO2 (x = 1, 2, 3, 4 and 5 mol%) glasses were prepared by melt-quenching and their thermal and structural properties were characterized by differential scanning calorimetry, Raman spectroscopy, high-energy X-ray diffraction and neutron diffraction and reverse Monte Carlo (RMC) simulations. The glass transition temperature increases steadily with an increase in V2O5 mol% in lithium tellurite glasses due to an increase in the average single bond energy of the glass network. The X-ray and neutron diffraction structure factors were modelled by RMC technique and the Te–O distributions show the first peak in the range 1.85–1.90 Å, with V–O = 1.75–1.95 Å, Li–O = 1.85–2.15 Å and O–O = 2.70–2.80 Å. The average Te–O coordination number decreases with an increase in Li2O mol% in lithium tellurite glasses, and the V—O coordination decreases from 5.12 to 3.81 with an increase in V2O5 concentration in vanadium lithium tellurite glasses. The O–Te–O, O–V–O, O–Li–O and O–O–O linkages have maxima in the ranges 86°–89°, 82°–87°, 80°–85° and at 59o, respectively. The structural analysis of tellurite glasses reveal significant short-range and medium-range disorder due to the existence of a wide range of Te–O and Te–Te distances in the first coordination shell.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

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