scholarly journals Induced Smectic Phases from Supramolecular H-Bonded Complexes Based on Non-Mesomorphic Components

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 940
Author(s):  
Fowzia S. Alamro ◽  
Hoda A. Ahmed ◽  
Magdi M. Naoum ◽  
Ayman M. Mostafa ◽  
Asmaa A. Alserehi
Keyword(s):  
Fatty Acids ◽  
Differential Scanning Calorimetry ◽  
Scanning Calorimetry ◽  
Acid Component ◽  
Smectic Phases ◽  
Ft Ir ◽  
The Stability ◽  
Oleic And Linoleic Acids ◽  
Ft Ir Spectroscopy ◽  
Induced Smectic Phases

New non-symmetrical 1:1 supramolecular H-bonded (SMHB) interactions, Ix/II, were designed between the non-mesomorphic fatty acids (palmitic, oleic and linoleic acids) and 4-tetradecyloxyphenylazo pyridine. Mesophase behaviors of the formed complexes were examined via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). In order to confirm the H-bond interaction formations within the prepared SMHB complexes, FT-IR spectroscopy was established whereby Fermi bands confirm these interactions. Mesomorphic investigations for all complexes indicated that, independent of the terminal alkenyl chains of the natural acids, induced dimorphic smectic phases were observed. The stability of formed mesophases was found to depend on the degree of un-saturation of the terminal alkenyl group of acid component.

GROWTH AND STUDIES OF PROPERTIES OF COPPER SUCCINATE DIHYDRATE SINGLE CRYSTALS

2013 ◽  
Vol 27 (11) ◽  
pp. 1350073
Author(s):  
M. P. BINITHA ◽  
P. P. PRADYUMNAN
Keyword(s):  
Differential Scanning Calorimetry ◽  
Dielectric Constant ◽  
Single Crystals ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Different Temperatures ◽  
Triclinic Structure ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Single crystals of copper succinate dihydrate (CSD) with triclinic structure were grown in silica gel medium. The functional groups in the crystal were analyzed by FT-IR Spectroscopy. Atomic Force Microscopy (AFM) revealed the striations on the surface of grown crystals, which were incorporated during its time of growth. Thermal degradation studies have been carried out by Differential Scanning Calorimetry (DSC). Dielectric constant and AC conductivity have been estimated as a function of frequency at different temperatures.

Synthesis and Characterization of Triethanolamine Borate

2013 ◽  
Vol 709 ◽  
pp. 28-31
Author(s):  
Cheng Xue Wang ◽  
Tian Tian Liang ◽  
Chun Qiao Wei
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Synthesis And Characterization ◽  
Spectroscopy Analysis ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Different Types ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Starting with boric acid and triethanolamine , the effect of the different types of the water-carrying agent on the yield was invested, and influences of dosage of water-carrying agent ,the mole ratio of reactants, reaction time on yield were discussed, the optimized reaction conditions were confirmed. The structure of the product was described by Fourier transform-infrared (FT-IR) spectroscopy, NMR Spectroscopy analysis, mass spectrometry (MS) and thermodynamic properties was analyzed by differential scanning calorimetry (DSC) and thermogravimetry (TG).

Mechanochemical synthesis insights and solid-state characterization of quininium aspirinate, a glass-forming drug–drug salt

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Nehemiah Harris ◽  
Jubilee Benedict ◽  
Diane A. Dickie ◽  
Silvina Pagola
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Ir Spectroscopy ◽  
Mechanochemical Synthesis ◽  
Mechanochemical Reaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Quinine (an antimalarial) and aspirin (a nonsteroidal anti-inflammatory drug) were combined into a new drug–drug salt, quininium aspirinate, C20H25N2O2 +·C9H7O4 −, by liquid-assisted grinding using stoichiometric amounts of the reactants in a 1:1 molar ratio, and water, EtOH, toluene, or heptane as additives. A tetrahydrofuran (THF) solution of the mechanochemical product prepared using EtOH as additive led to a single crystal of the same material obtained by mechanochemistry, which was used for crystal structure determination at 100 K. Powder X-ray diffraction ruled out crystallographic phase transitions in the 100–295 K interval. Neat mechanical treatment (in a mortar and pestle, or in a ball mill at 20 or 30 Hz milling frequencies) gave rise to an amorphous phase, as shown by powder X-ray diffraction; however, FT–IR spectroscopy unambiguously indicates that a mechanochemical reaction has occurred. Neat milling the reactants at 10 and 15 Hz led to incomplete reactions. Thermogravimetry and differential scanning calorimetry indicate that the amorphous and crystalline mechanochemical products form glasses/supercooled liquids before melting, and do not recrystallize upon cooling. However, the amorphous material obtained by neat grinding crystallizes upon storage into the salt reported. The mechanochemical synthesis, crystal structure analysis, Hirshfeld surfaces, powder X-ray diffraction, thermogravimetry, differential scanning calorimetry, FT–IR spectroscopy, and aqueous solubility of quininium aspirinate are herein reported.

scholarly journals Star-Shaped Polydimethylsiloxanes with Organocyclotetrasilsesquioxane Branching-Out Centers: Synthesis and Properties

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 285
Author(s):  
Yulia S. Dyuzhikova ◽  
Anton A. Anisimov ◽  
Alexander S. Peregudov ◽  
Mikhail I. Buzin ◽  
Galina G. Nikiforova ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Physicochemical Analysis ◽  
Langmuir Trough ◽  
Scanning Calorimetry ◽  
Gel Permeation ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

New non-crystallizable low-dispersity star-shaped polydimethylsiloxanes (PDMS) containing stereoregular cis-tetra(organo)(dimethylsiloxy)cyclotetrasiloxanes containing methyl-, tolyl- and phenyl-substituents at silicon atoms and the mixture of four stereoisomers of tetra[phenyl(dimethylsiloxy)]cyclotetrasiloxane as the cores were synthesized. Their thermal and viscous properties were studied. All synthesized compounds were characterized by a complex of physicochemical analysis methods: nuclear magnetic resonance (NMR), FT-IR spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), viscometry in solution, rheometry, and Langmuir trough study.

scholarly journals Swelling properties of chitosan hydrogels

2004 ◽  
Vol 22 (1) ◽  
pp. 32 ◽  
Author(s):  
David R Rohindra ◽  
Ashveen V Nand ◽  
Jagjit R Khurma
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Glass Transition ◽  
Free Water ◽  
Scanning Calorimetry ◽  
Swelling Behaviour ◽  
Swelling Properties ◽  
Different Temperatures ◽  
Ft Ir ◽  
Chitosan Hydrogels

Chitosan hydrogels were prepared by crosslinking chitosan with glutaraldehyde. The swelling behaviour of the crosslinked and uncross-linked hydrogels was measured by swelling the gels in media of different pH and at different temperatures. The swelling behavior was observed to be dependent on pH, temperature and the degree of crosslinking. The gel films were characterized by Fourier transform Infrared spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC). The glass transition temperature (Tg) and the amount of free water in the hydrogels decreased with increasing crosslinking in the hydrogels.

Solid-liquid phase equilibrium diagrams of binary mixtures containing fatty acids, fatty alcohol compounds and tripalmitin using differential scanning calorimetry

2019 ◽  
Vol 497 ◽  
pp. 19-32 ◽  
Author(s):  
Fernanda Paludetto Pelaquim ◽  
Flávio Cardoso de Matos ◽  
Lisandro Pavie Cardoso ◽  
Eduardo Augusto Caldas Batista ◽  
Antonio José de Almeida Meirelles ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Differential Scanning Calorimetry ◽  
Phase Equilibrium ◽  
Liquid Phase ◽  
Binary Mixtures ◽  
Fatty Alcohol ◽  
Scanning Calorimetry ◽  
Solid Liquid

Compatibility between Magnesium Stearate and Pharmaceutical Acidic Active Compounds/Excipients with DSC

2020 ◽  
Vol 856 ◽  
pp. 190-197
Author(s):  
Pornsit Chaiya ◽  
Thawatchai Phaechamud
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnesium Stearate ◽  
X Ray Diffraction ◽  
Salt Form ◽  
Scanning Calorimetry ◽  
Powder Mixtures ◽  
X Ray ◽  
Pharmaceutical Excipients ◽  
Drug Compounds ◽  
Ft Ir

Compatibility investigation was performed between magnesium stearate and acidic drug compounds (ibuprofen, indomethacin and valproic acid) and acidic pharmaceutical excipients (lactic acid and citric acid) using differential scanning calorimetry (DSC). DSC study indicated the possible incompatibility for the mixture between magnesium stearate and any compounds. Alteration in DSC thermogram was found in all mixtures. The eutectic phenomenon was found in the powder mixture of magnesium stearate and ibuprofen. In addition, the presence of melting endothermic peak of stearic acid in other powder mixtures except the mixture of magnesium stearate and indomethacin indicating breakage of salt form of magnesium stearate. This alteration could relate to the influence on physicochemical properties of drug compounds and pharmaceutical excipients which powder x-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FT-IR) should be further analyzed to confirm the interactions between compounds.

Study on Host-Guest Inclusion Complexation of a Drug in Cucurbit [6]uril

2018 ◽  
Vol 232 (2) ◽  
pp. 281-293 ◽  
Author(s):  
Kanak Roy ◽  
Subhadeep Saha ◽  
Biswajit Datta ◽  
Lovely Sarkar ◽  
Mahendra Nath Roy
Keyword(s):  
Surface Tension ◽  
Specific Conductivity ◽  
Inclusion Complexation ◽  
Conductivity Measurements ◽  
Saline Environment ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
The Stability ◽  
Ft Ir Spectroscopy

AbstractAssembly of pyridine-2-aldoxime drug with cucurbit [6]uril (CB[6]) has been investigated by1H-NMR and 2D-ROESY NMR, UV-Vis spectroscopy, FT-IR spectroscopy, surface tension and conductivity measurements in aqueous saline environment. The distinct cationic receptor feature and the cavity dimension of the CB[6] emphasize that the macro-cyclic host molecule remain as complex with the nerve stimulus drug molecule. The results obtained from surface tension and specific conductivity measurements suggest 1:1 inclusion complex formation between drug and CB[6]. The stability constant evaluated by UV-Vis spectroscopic approach is 2.21×105M−1at 298.15 K, which indicates that the complex is sufficiently stable at physiological temperature.

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