scholarly journals A Comprehensive Study of a New 1.75 Hydrate of Ciprofloxacin Salicylate: SCXRD Structure Determination, Solid Characterization, Water Stability, Solubility, and Dissolution Study

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 349 ◽  
Author(s):  
Ilma Nugrahani ◽  
Billgerd Tjengal ◽  
Tutus Gusdinar ◽  
Ayano Horikawa ◽  
Hidehiro Uekusa
Keyword(s):  
Thermal Analysis ◽  
Raman Spectroscopy ◽  
Salicylic Acid ◽  
Solid Phase ◽  
Linear Regression Method ◽  
X Ray ◽  
Dissolution Tests ◽  
Hydrate Crystal ◽  
Uv Visible ◽  
Comprehensive Study

One problem that often arises during the formulation of a dosage form is the solubility and dissolution of the active ingredients. This problem arises in ciprofloxacin, which is a BCS class IV fluoroquinolone antibiotic. A pseudopolymorph is a kind of polymorph in which the number of hydrates is different. In this study, a new pseudopolymorph comprised of ciprofloxacin and salicylic acid was found, namely the salt ciprofloxacin salicylate 1.75 hydrate form. This new solid phase was analyzed by Fourier-transform infrared spectroscope (FTIR), Raman spectroscopy, and thermal analysis and proven by Powder X-ray Diffractometry (PXRD) analysis. The crystal structure was successfully determined by Single Crystal X-ray Diffractometry (SCXRD) analysis. It was found that the piperazinyl group of ciprofloxacin is protonated by H+ from the carboxylic group of salicylic acid. In the unit cell, two ciprofloxacin and two salicylic acid molecules were independent with four water molecules, in which one water molecule had 0.5 occupancy due to inversion symmetry. Interestingly, this hydrate crystal dehydrated by grinding for 105 minutes forms an anhydrous crystalline phase, which was analyzed with FTIR, Raman spectroscopy, thermal analysis, and PXRD. The solubility and dissolution tests were carried out using UV-Visible spectrophotometry and a multiple linear regression method. This new hydrate solid phase has a better profile than the original ciprofloxacin crystal, according to the solubility and dissolution tests.

TiO2 nanofibers fabricated by electrospinning technique and degradation of MO dye under UV light

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Naveen Thakur ◽  
Nikesh Thakur ◽  
Viplove Bhullar ◽  
Saurabh Sharma ◽  
Aman Mahajan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fiber Diameter ◽  
Uv Light ◽  
Rutile Phase ◽  
Powder Form ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Tio2 Nanofibers ◽  
X Ray ◽  
Uv Visible

Abstract Titanium dioxide (TiO2) nanofibers were synthesized by electrospinning to optimize the photocatalytic action efficiency. The synthesis of the fibers was carried out at four different wt% concentrations: 8, 9, 10 & 11% of polymer polyvinylpyrrolidone (PVP). The TiO2 fibers were further calcined at 700 °C to get powder form. The uncalcinated and calcined TiO2 nanofibers were characterized by using X-Ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) and UV-Visible spectroscopy. Raman spectroscopy confirmed the rutile phase of the calcined TiO2nanofibers in powder form with a crystallite size of 34–38 nm. The surface morphology of the uncalcinated and calcined TiO2 nanofibers was examined by SEM and the fiber diameter found to be 360–540 nm. The optical bandgap of the calcined TiO2 nanofibers was found in the range of 3.29–3.24 eV. The photocatalytic activity of the TiO2 nanofibers as examined for uncalcinated and calcined nanofibers, methyl orange (MO) dye degraded up to 98 and 78%, respectively in 180 min under the exposure of UV light. Uncalcinated TiO2 nanofibers were found more suitable for degradation of MO dye as compared to calcined nanofibers.

scholarly journals Effect of Mg/Al molar ratio on the basicity of Mg-Al mixed oxide derived from Mg-Al hydrotalcite

2020 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Said Arhzaf ◽  
Mohammed Naciri Bennani ◽  
Sadik Abouarnadasse ◽  
Hamid Ziyat ◽  
Omar Qabaqous
Keyword(s):  
Thermal Analysis ◽  
Mixed Oxide ◽  
Mixed Oxides ◽  
Molar Ratio ◽  
Acid Molecule ◽  
X Ray Diffraction ◽  
Phenol Adsorption ◽  
X Ray ◽  
Maximum Quantity ◽  
Uv Visible

<p>The fundamental character of the Mg-Al mixed oxide (Mg<sub>n</sub>(Al)O), derived from the Mg-Al hydrotalcite (Mg<sub>n</sub>Al-CO<sub>3</sub>-HT), where n corresponds to the Mg/Al molar ratio (n: 2, 2.5, 3, 3.5 and 4), was studied by using the adsorption of phenol as a probe acid molecule. The hydrotalcite precursors were prepared by the coprecipitation method. Their derived mixed oxides were obtained by thermal treatment at 450°C in a flow of air. The resulting solids were characterized by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric and differential thermal analysis             (TG-DTA), nitrogen physisorption (BET) and phenol chemisorption. The phenol adsorption followed by UV-Visible spectrophotometry shows that the basicity increases with the Mg/Al molar ratio, such that maximum quantity of phenol adsorbed (Q<sub>ads</sub> = 0.54 mmol/g <sub>cat</sub>) was obtained with the mixed oxide derived from the Mg-Al hydrotalcite of Mg/Al molar ratio equal to 3.5.</p>

Study on integration of aluminum-doped zinc oxide (AZO) thin films with graphene oxide (GO)

2018 ◽  
Vol 32 (19) ◽  
pp. 1840044
Author(s):  
Aditya Dalal ◽  
Animesh Mandal ◽  
Shubhada Adhi ◽  
Kiran Adhi
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Aluminum Doped Zinc Oxide ◽  
Uv Visible

Aluminum (0.5 at.%)-doped ZnO (AZO) thin films were deposited by pulsed laser deposition technique (PLD) in oxygen ambient of 10[Formula: see text] Torr. The deposited thin films were characterized by x-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy and uv–visible spectroscopy (UV–vis). Next, graphene oxide (GO) was synthesized by Hummers method and was characterized by XRD, UV–vis spectroscopy, Raman spectroscopy and transmission electron microscopy (TEM). Thereafter, GO solution was drop-casted on AZO thin films. These films were then characterized by Raman Spectroscopy, UV–vis spectroscopy and PL. Attempt is being made to comprehend the modifications in properties brought about by integration.

Solid phase precipitates in (Zr,Th)-OH-(oxalate, malonate) ternary aqueous system

2009 ◽  
Vol 97 (4-5) ◽  
Author(s):  
Taishi Kobayashi ◽  
Takayuki Sasaki ◽  
I. Takagi ◽  
Hirotake Moriyama
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Solid Phase ◽  
Aqueous System ◽  
Carboxylate Ligand ◽  
X Ray Diffraction ◽  
Large Excess ◽  
X Ray ◽  
Acidic Conditions ◽  
Solid Phases

AbstractThe solubility-limiting solid phases in the ternary aqueous systems of Zr(IV)/OH/oxalate, Zr(IV)/OH/malonate, Th(IV)/OH/oxalate and Th(IV)/OH/malonate were characterized by elemental analysis, X-ray diffraction, thermogravimetric analysis and differential thermal analysis. The ternary solid phase of M(IV)/OH/carboxylate was observed to form, even under acidic conditions, depending on the pH and the concentration of carboxylate ligand. In the presence of a large excess of carboxylic acid, however; the binary M(IV)-carboxylate solid phase formed.

Analysis of the Crystallization Kinetics and Microstructure of Polycrystalline Sige Films by Optical Techniques

1999 ◽  
Vol 588 ◽  
Author(s):  
J. Olivares ◽  
P. Martín ◽  
A. Rodríguez ◽  
J. Sangrador ◽  
O. Martínez ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Crystallization Kinetics ◽  
Solid Phase ◽  
Grain Morphology ◽  
Optical Techniques ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Reflectance ◽  
The One ◽  
Means Of Transmission

AbstractIn this work, two optical techniques, Raman spectroscopy and ultraviolet reflectance, have been used to characterize the solid phase crystallization kinetics and the microstructure of SiGe films deposited by LPCVD on oxidized Si wafers. The results have been compared to those obtained by X-ray diffractometry. The Ge fraction of the films (x) was in the 0−0.38 interval. The samples were crystallized at temperatures ranging from 525 to 600 °C. The crystallization kinetics follows Avrami's model. Two different behaviours have been observed depending on the Ge fraction of the films and the crystallization temperature: a) Either the three experimental techniques yield similar results, or b) the crystallization process, as monitored by UV reflectance and Raman spectroscopy, exhibits a greater incubation time than the one obtained if X-ray diffractometry is used. The results are discussed in terms of the identification of the nucleation sites, taking into account the probe depth of the different techniques and the preferred orientations of the grains. These techniques have also been used to characterize the presence of defects, the overall crystallinity and the surface roughness of the fully crystallized films. The results are correlated to the grain morphology and grain size, obtained by means of transmission electron microscopy.

scholarly journals Thermal Annealing and Phase Transformation of Serpentine-Like Garnierite

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 188
Author(s):  
Arun Kumar ◽  
Michele Cassetta ◽  
Marco Giarola ◽  
Marco Zanatta ◽  
Monique Le Guen ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Raman Spectroscopy ◽  
Phase Transformation ◽  
Differential Thermal Analysis ◽  
Thermal Treatment ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Micro Raman Spectroscopy

This study is focused on the vibrational and microstructural aspects of the thermally induced transformation of serpentine-like garnierite into quartz, forsterite, and enstatite occurring at about 620 °C. Powder specimens of garnierite were annealed in static air between room temperature and 1000 °C. The kinetic of the transformation was investigated by means of thermogravimetric and differential thermal analysis, and the final product was extensively characterized via micro-Raman spectroscopy and X-ray diffraction. Our study shows that serpentine-like garnierite consists of a mixture of different mineral species. Furthermore, these garnierites and their composition can provide details based on the mineralogy and the crystalline phases resulting from the thermal treatment.

Dehydration processes in borate minerals: pentahydroborite and nifontovite from Fuka Mine, Okayama Prefecture, Japan

2010 ◽  
Vol 74 (6) ◽  
pp. 1013-1025 ◽  
Author(s):  
V. Bermanec ◽  
N. Tomašić ◽  
Ž. Žigovečki Gobac ◽  
M. Rajić Linarić ◽  
K. Furić
Keyword(s):  
Thermal Analysis ◽  
Raman Spectroscopy ◽  
Differential Thermal Analysis ◽  
Calcium Borate ◽  
X Ray Diffraction ◽  
Critical Temperatures ◽  
X Ray ◽  
Borate Minerals ◽  
Dehydration Processes ◽  
Okayama Prefecture

AbstractData on the dehydration of pentahydroborite, CaB2O(OH)6·2H2O and nifontovite, Ca3B6O6(OH)12·2H2O from the Fuka mine, Japan are presented. Critical temperatures of the dehydration of the borates were determined by thermogravimetric analysis/differential thermal analysis measurements. The untreated mineral samples and their heating products were investigated by X-ray diffraction and Raman spectroscopy. Upon dehydration, both minerals decompose and undergo amorphization, and at greater temperatures crystallize as an orthorhombic calcium borate, CaB2O4 (Pnca). The dehydration paths of the two minerals are different, with nifontovite showing a greater resistance to decomposition and amorphization than pentahydroborite. Differences in the dehydration processes are related to the residuals of the water content and structural accommodation of the borate polyanion.

scholarly journals Metamorphic graphite from Szendrőlád (Szendrő Mts., NE-Hungary) detected by simultaneous DTA-TG

2021 ◽  
Author(s):  
Lívia Majoros ◽  
Krisztián Fintor ◽  
Tamás Koós ◽  
Sándor Szakáll ◽  
Ferenc Kristály
Keyword(s):  
Thermal Analysis ◽  
Raman Spectroscopy ◽  
Powder Diffraction ◽  
Automobile Industry ◽  
Raw Materials ◽  
Regional Metamorphism ◽  
High Tech ◽  
Raman Spectrometry ◽  
X Ray ◽  
Forms Of Carbon

AbstractGraphite, one of the polymorphic forms of carbon, has become a versatile industrial material of nowadays due to its particular attributes. It is used mainly in the automobile industry, metal extractive industry and in the high-tech industry. Moreover, it is also included in the list of critical raw materials for the EU. Our aim was to prove the presence of graphite by thermal analysis beyond X-ray powder diffraction (XRD) and Raman spectroscopy. Thermogravimetry yields comparable results with quantitative XRD. The formation conditions are described by Raman spectrometry and microscopy examinations of drill core samples from Szendrőlád (Szendrő Mts, NE-Hungary; (Szendrőlád Limestone Formation, middle-late Devonian, shelf-basin facies). Polished rock slabs were made for optical microscopy, scanning electron microscopy with energy dispersive spectrometry (SEM–EDS) and Raman spectroscopy. X-ray powder diffraction (XRD) and thermal analysis (DTA-TG) measurements were made on powders. Based on our results, the graphite is epigenetic; its quantity varies between 1.5–3 mass% in the samples. It was developed in 20–50 μm sized flakes, which are often arranged in > 300 μm sized aggregates. Graphite was formed during regional metamorphism from the organic matter-rich shales. The average formation temperature, calculated from the results of Raman spectroscopy, is around 410 °C (± 30 °C). The Raman measurements also indicated the presence of a partially graphitized (disordered graphite) material beside graphite.

Cyanoplatinate Halides – Synthesis, Crystal Structure Analyses and Vibrational Spectroscopy of Compounds A2[Pt(CN)4X2] (A = Rb, Cs; X = Cl, Br, I)

2010 ◽  
Vol 65 (9) ◽  
pp. 1066-1072 ◽  
Author(s):  
Claus Mühle ◽  
Jürgen Nuss ◽  
Robert E. Dinnebier ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Raman Spectroscopy ◽  
Differential Thermal Analysis ◽  
Alkali Metal ◽  
X Ray ◽  
Infrared And Raman Spectroscopy ◽  
In Trans ◽  
Cyanide Ligands ◽  
Single Crystal Analysis

Crystal structures of the cyanoplatinates A2[Pt(CN)4X2] (A = Rb, Cs; X = Cl, Br, I) have been determined by single-crystal analysis and X-ray powder diffraction. The compounds were synthesized by metathesis from Ba[Pt(CN)4] ·4 H2O and alkali metal sulfates, and by subsequent oxidation with the respective halogens. The crystals were grown by slowly concentrating respective aqueous solutions. The PtIV cations are octahedrally coordinated by four cyanide ligands and two halogen atoms, the latter being located in trans positions. Rb2[Pt(CN)4Cl2]: triclinic, P¯1 (Z = 2), a = 6.7779(2), b = 9.3149(3), c = 9.6707(3) Å , α = 89.37(0), β = 76.05(0), γ = 72.98(0)◦, V = 565.42(2) Å3, N` hkl= 5616, R(F)N` = 0.0273; Rb2[Pt(CN)4I2]: monoclinic, P21/c (Z = 2), a = 7.4239(2), b = 9.2486(2), c = 9.1189(2) Å , β = 107.22(3)◦, V = 598.04(6) Å3, N` hkl = 2917, R(F)N` = 0.0295; Cs2[Pt(CN)4I2]: monoclinic, P21/c (Z = 2), a = 7.6740(4), b = 9.5397(5), c = 9.3474(5) Å , β = 106.46(0)◦, V = 656.3(2) Å3, Z = 2, N` hkl = 2738, R(F)N` = 0.0283; Cs2[Pt(CN)4Cl2]: monoclinic, C2/c (Z = 4), a = 17.947(4), b = 7.395(2), c = 12.031(3) Å , β = 131.904(1)◦, V = 1188.4(5) Å3, R-wp = 2.77; Cs2[Pt(CN)4Br2]: monoclinic, C2/c (Z = 4), a = 18.404(1), b = 7.2819(5), c = 12.4156(8) Å , β = 132.156(1)◦, V = 1233.5(1) Å3, N` hkl = 2566, R(F)N` = 0.0268. All compounds were characterized by differential thermal analysis, thermogravimetry, and infrared and Raman spectroscopy.

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