scholarly journals Hydrogel networks by aliphatic dithiol Michael addition to glycidylmethacrylated gelatin

MRS Advances ◽  
2021 ◽  
Author(s):  
Axel T. Neffe ◽  
Candy Löwenberg ◽  
Andreas Lendlein
Keyword(s):  
Network Formation ◽  
Molar Ratio ◽  
Elongation At Break ◽  
X Ray ◽  
H Nmr ◽  
X Ray Scattering ◽  
Ft Ir ◽  
Triple Helices ◽  
Hydrogel Swelling ◽  
Ft Ir Spectroscopy

AbstractFunctionalization of gelatin with glycidylmethacrylate (GMA-gelatin) enables network formation employing the double bond, so that the reaction is orthogonal to the inherent functional groups in the biomacromolecule. Here, network formation by crosslinking of GMA-gelatin with hexane 1,6-dithiol or nonane 1,9-dithiol to tailor properties and enable a shape-memory effect is shown by 1H NMR and FT-IR spectroscopy. Hydrogel swelling (460–1900 vol%) and mechanical properties (Young’s modulus E = 59–512 kPa, elongation at break εb = 44–127%) depended on the molecular composition of the networks and temperature. Increased crosslinker length, thiol:methacrylate molar ratio, and precursor concentrations led to denser networks. Change of properties with temperature suggested adoption of triple helices by gelatin chains, forming physical netpoints at lower temperatures (< 20 °C). However, the limited freedom of the gelatin chains to move allowed only a minimal extent of triple helices formation, as it became apparent from the related signal in wide-angle X-ray scattering and the thermal transition associated to triple helices in some networks by DSC. The presented strategy is likely transferable to other biomacromolecules, and the results suggest that too short crosslinkers may result in a significant amount of grafting rather than network formation. Graphic abstract

Reaction of 2-[(2-aminoethyl)amino]ethanol with pyridine-2-carbaldehyde and complexation of the products with CuII and CdII along with docking studies

2019 ◽  
Vol 75 (7) ◽  
pp. 951-959 ◽  
Author(s):  
Zahra Mardani ◽  
Mohammad Hakimi ◽  
Keyvan Moeini ◽  
Fabian Mohr
Keyword(s):  
Crystal Packing ◽  
Docking Studies ◽  
Molar Ratio ◽  
Distorted Octahedral Geometry ◽  
X Ray Diffraction ◽  
Donor Ligand ◽  
X Ray ◽  
H Nmr ◽  
Distorted Octahedral ◽  
Ft Ir

The reaction between 2-[2-(aminoethyl)amino]ethanol and pyridine-2-carbaldehyde in a 1:2 molar ratio affords a mixture containing 2-({2-[(pyridin-2-ylmethylidene)amino]ethyl}amino)ethanol (PMAE) and 2-[2-(pyridin-2-yl)oxazolidin-3-yl]-N-(pyridin-2-ylmethylidene)ethanamine (POPME). Treatment of this mixture with copper(II) chloride or cadmium(II) chloride gave trichlorido[(2-hydroxyethyl)({2-[(pyridin-2-ylmethylidene)amino]ethyl})azanium]copper(II) monohydrate, [Cu(C10H16N3O)Cl3]·H2O or [Cu(HPMAE)Cl3]·H2O, 1, and dichlorido{2-[2-(pyridin-2-yl)oxazolidin-3-yl]-N-(pyridin-2-ylmethylidene)ethanamine}cadmium(II), [CdCl2(C16H18N4O)] or [CdCl2(POPME)], 2, which were characterized by elemental analysis, FT–IR, Raman and 1H NMR spectroscopy and single-crystal X-ray diffraction. PMAE is potentially a tetradentate N3O-donor ligand but coordinates to copper here as an N2 donor. In the structure of 1, the geometry around the Cu atom is distorted square pyramidal. In 2, the Cd atom has a distorted octahedral geometry. In addition to the hydrogen bonds, there are π–π stacking interactions between the pyridine rings in the crystal packing of 1 and 2. The ability of PMAE, POPME and 1 to interact with ten selected biomolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B-DNA) was investigated by docking studies and compared with doxorubicin.

Synthesis of Posnjakite Nanoparticles in the Presence of a New Capping Agent

2016 ◽  
Vol 35 (5) ◽  
pp. 457-462 ◽  
Author(s):  
Mehdi Bazarganipour ◽  
Mahnaz Sahebi-Harandi ◽  
Masoud Salavati-Niasari
Keyword(s):  
Microwave Power ◽  
Irradiation Time ◽  
Heating Time ◽  
Molar Ratio ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Methylene Orange ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

AbstractPosnjakite nanoparticles, Cu4SO4(OH)6 · H2O, were synthesized by utilizing a new thio-Schiff base ligand as new capping agent via a microwave approach. The effects of molar ratio, surfactants, heating time and microwave power on morphology of the product were investigated. The as-synthesized posnjakite nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and energy dispersive X-ray analysis (EDAX). The effects of different parameters such as the molar ratio, surfactants, microwave power and irradiation time on the morphology of the products were investigated. Moreover, adsorption of methylene orange dye on posnjakite nanoparticles was considered and the uptake percent was determined to be >65% in 200 min.

A study of the effect of annealing on Fe-doped LiNbO3by HRXRD, XRT and FT–IR

2005 ◽  
Vol 38 (5) ◽  
pp. 768-771 ◽  
Author(s):  
G. Bhagavannarayana ◽  
R. V. Ananthamurthy ◽  
G. C. Budakoti ◽  
B. Kumar ◽  
K. S. Bartwal
Keyword(s):  
Fourier Transform ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Elevated Temperatures ◽  
Annealing Effect ◽  
Molar Ratio ◽  
Structural Perfection ◽  
X Ray ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The annealing effect on the structural perfection of Fe-doped LiNbO3single crystals has been studied by high-resolution X-ray diffractometry (HRXRD), X-ray topography (XRT) and Fourier transform infrared (FT–IR) spectroscopy. The single crystals, prepared by mixing Li2CO3and Nb2O5powders in the molar ratio 48.6:51.4 with 0.05 mol% of iron at 1415 (1) K, were grown by the Czochralski (CZ) method along the [001] direction in air and poled during crystal growth by the application of a DC field. Two low-angle (tilt angle ∼1 arc minute) structural grain boundaries were observed in as-grown specimens. FT–IR spectra revealed that these crystals contain OH−and CO32−ionic defects. Grain boundaries and CO32−ionic defects were successfully removed, while the concentration of OH−ions was considerably reduced by post-growth thermal annealing at elevated temperatures.

scholarly journals Multicomponent Materials to Improve Solubility: Eutectics of Drug Aminoglutethimide

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 40
Author(s):  
Basanta Saikia ◽  
Andreas Seidel-Morgenstern ◽  
Heike Lorenz
Keyword(s):  
Melting Point ◽  
Molar Ratio ◽  
Experimental Characterization ◽  
X Ray ◽  
Eutectic Mixtures ◽  
Ft Ir ◽  
Aqueous Solubilities ◽  
Ft Ir Spectroscopy

Here, we report the synthesis and experimental characterization of three drug-drug eutectic mixtures of drug aminoglutethimide (AMG) with caffeine (CAF), nicotinamide (NIC) and ethenzamide (ZMD). The eutectic mixtures i.e., AMG-CAF (1:0.4, molar ratio), AMG-NIC (1:1.9, molar ratio) and AMG-ZMD (1:1.4, molar ratio) demonstrate significant melting point depressions ranging from 99.2 to 127.2 °C compared to the melting point of the drug AMG (151 °C) and also show moderately higher aqueous solubilities than that of the AMG. The results presented include the determination of the binary melt phase diagrams and accompanying analytical characterization via X-ray powder diffraction, FT-IR spectroscopy and scanning electron microscopy.

scholarly journals Structure and excitation-dependent emission of novel zinc complexes with pyridyltriazoles

RSC Advances ◽  
2019 ◽  
Vol 9 (38) ◽  
pp. 22143-22152 ◽  
Author(s):  
Alexey Gusev ◽  
Elena Braga ◽  
Ekaterina Zamnius ◽  
Mikhail Kiskin ◽  
Mariya Kryukova ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Single Crystal ◽  
Zinc Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Esi Ms ◽  
H Nmr ◽  
Elemental Analyses ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A series of Zn(ii) complexes with 5-(4-R-phenyl)-3-(pyridin-2-yl)-1,2,4-triazoles have been synthesized and subsequently characterized by single crystal X-ray diffraction, 1H-NMR, FT-IR spectroscopy, elemental analyses, ESI-MS, and PXRD.

scholarly journals DINUCLEAR COPPER(II) ACETATE COMPLEX WITH CAFFEINE, A FAST MECHANOCHEMICAL SYNTHESIS

2018 ◽  
Vol 39 (2) ◽  
pp. 91
Author(s):  
Marina Tašner ◽  
Draginja Mrvoš-Sermek ◽  
Emina Hajdarpašić ◽  
Dubravka Matković-Čalogović
Keyword(s):  
Mechanochemical Synthesis ◽  
Complex Molecule ◽  
Diffraction Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acetate Complex ◽  
Reaction Proceeds ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A new dinuclear paddle-wheel copper(II) complex with caffeine was synthesized by the solvent-based and mechanochemical methods from copper(II) acetate and caffeine in a 1:1 molar ratio. Mechanochemical synthesis was found to be the fastest and easiest way to prepare the complex. The reaction proceeds with addition of small amounts of methanol or ethanol. The complex was characterized by FT-IR spectroscopy, elemental and thermoanalytical methods (TG and DSC) and X-ray diffraction methods. The molecular and crystal structure was determined by the single crystal X-ray diffraction method. The complex molecule consists of a centrosymmetric dinuclear unit, Cu2(-Ac)4(caf)2, with two copper(II) atoms bridged by four acetato groups, and N-coordinated caffeine (caf) molecules in the apical posi-tions.

scholarly journals Ethylene oxide sterilization of electrospun poly(l-lactide)/poly(d-lactide) core/shell nanofibers

MRS Advances ◽  
2021 ◽  
Author(s):  
Axel T. Neffe ◽  
Quanchao Zhang ◽  
Paul J. Hommes-Schattmann ◽  
Andreas Lendlein
Keyword(s):  
Ethylene Oxide ◽  
Molar Mass ◽  
Shell Morphology ◽  
Material Structure ◽  
Core Shell ◽  
Elongation At Break ◽  
X Ray ◽  
H Nmr ◽  
X Ray Scattering ◽  
Ethylene Oxide Sterilization

Abstract The application of polymers in medicine requires sterilization while retaining material structure and properties. This demands detailed analysis, which we show exemplarily for the sterilization of PLLA/PDLA core–shell nanofibers with ethylene oxide (EtO). The electrospun patch was exposed to EtO gas (6 vol% in CO2, 1.7 bar) for 3 h at 45 °C and 75% rel. humidity, followed by degassing under pressure/vacuum cycles for 12 h. GC–MS analysis showed that no residual EtO was retained. Fiber diameters (~ 520 ± 130 nm) of the patches remained constant as observed by electron microscopy. Young’s modulus slightly increased and the elongation at break slightly decreased, determined at 37 °C. No changes were detected in 1H-NMR spectra, in molar mass distribution (GPC) or in crystallinity measured for annealed samples with comparable thermal history (Wide Angle X-Ray Scattering). Altogether, EtO emerged as suitable sterilization method for polylactide nanofibers with core–shell morphology. Graphic abstract

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