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The phase transition temperatures for amorphous metals based on aluminum Al87(Ni,Fe)8(REM)5 system were determined by differential scanning calorimetry (DSC). The mechanisms of formation and growth of nanocrystals in an amorphous matrix were predicted using kinetic models (Matusita model). It was found that after annealing at the temperature of stable nanocrystalline growth, an X-ray amorphous structure with a volume fraction of disordered nanocrystalline phases of solid state of Al(X), GdFe2, AlFe2Ni, GdFe2 for the amorphous metal alloy (AMA) Al87Y4Gd1Ni4Fe4 alloy and microcrystalline phases of solid state of Al(X), GdFe2 AlFe2Ni for the Al87Gd5Ni4Fe4 alloy are formed, which significantly affects the mechanical properties of the Al87(Ni,Fe)8(REM)5 system. The effect of annealing on the mechanical properties of amorphous aluminum-based alloys was investigated using Oliver-Pharr and Young's modulus methods it was found that thermal modification of AMAs: Al87Gd5Ni4Fe4 as a result of heat treatment of AMAs from 5 to 15 min., the microhardness increases from 0.20 GPa to 2.75 GPa, and when heat treated for 60 min at a temperatures of T3 = 645±5 K, 647±5 K, it decreases to 0.35 GPa and 0.45 GPa, respectively.

Background: Intercomponent drug interactions could play important role for drug release, membrane permeability and membranotropic action. Therefore, newly developed drugs need for checking their biopharmaceutical characteristics. A new analgetic drug based on paracetamol (Actimask® Acetaminoprofen) and a hepatoprotector N-acetyl-D-glucosamine has been developed, with increased safety and potentiation of the analgesic effect (Ruban O., 2022). Multibilayer lipid membranes were chosen as promising testing medium due to their proved appropriation and sensitivity for study multi-compound drug-membrane interactions. It is the basis for a kinetic approach allowing elucidation of biopharmaceutical interactions in model membrane medium. Objectives: Revealing changes of paracetamol release and membrane penetration in the new paracetamol-glucosamine analgetic drug as well as estimation the rationale of the approach developed to trace biopharmaceutical interactions in model membrane medium. Materials and Methods: L-a-dimyristoyl phosphatidylcholine (DMPC) multibilayer membrane was used as a model biomimetic testing medium. Differential scanning calorimetry (DSC) was applicated to trace kinetics of drug-membrane interactions. Results: Gelatin as a part of Actimask® increased the characteristic time of paracetamol diffusion about threefold, but it had no pronounced effect on the equilibrium paracetamol penetration into the membrane. Sole glucosamine manifested no membranotropic effect under the experimental conditions, however, in combination with gelatin, it sufficiently reduced equilibrium paracetamol penetration while paracetamol diffusion remained within the experimental error. The full drug formulation increased membrantoropic effect by 34 % in compared with sole paracetamol. Conclusions: Glucosamine and gelatin can affect both kinetic and equilibrium parameters of paracetamol-membrane interactions, while the full set of the drug components is able to increase the effect which correlates well with the previously established enhancement of analgetic effect of the drugs. The approach developed allows accurate tracing of drug release and membrane penetration depending on a set of drug components. Generally, the results obtained prove the rationale of applying the approach to pre-clinical drug examination.

Organic–inorganic hybrid materials are synthesized on the base of anhydride-cured epoxyurethane polymer matrix with an ultra-low content of poly(titanium oxide) nanoparticles (0.005 and 0.020 wt.% for TiO2) obtained in situ by the sol–gel method in polyoxypropylene glycol medium. The structure of the formed optically transparent samples was confirmed by the methods of optical microscopy and wide-angle x-ray scattering. As shown, TiO2 reveals itself as an amorphous phase and does not form aggregates of large size (>200 nm). The behaviour of the neat epoxyurethane and of titanium-containing ones is studied under artificially accelerated weathering conditions in a climate chamber. The changes in the properties of films after exposure to UV radiation, elevated temperature and relative humidity are investigated by the methods of IR spectroscopy, hydrostatic weighting, differential scanning calorimetry, thermogravimetric analysis, and spectrophotometry. As found, under the influence of such climatic factors, the chemical structure of the samples changes insignificantly that proves their atmospheric stability. The increase in density and initial temperatures of thermal decomposition as well as the decrease in the increment of heat capacity (ΔCp ) of epoxyurethanes indicate the proceeding of cross-linking reactions via condensation of hydroxyl groups in the conditions of the climate chamber, which lead to the formation of a denser structure. After accelerated weathering test, the optical transmission coefficient of all the samples diminishes slightly, but the loss of transparency decreases with increasing content of poly(titanium oxide) (18.2% for the neat epoxyurethane polymer and 11.6% for the sample with 0.020 wt.% TiO2). In general, modified epoxyurethanes have a higher resistance to degradation compared to the unmodified ones that is an evidence of the exhibiting of the UV-shielding properties of TiO2 and the simultaneous absence of its photocatalytic activity, which, on the contrary, would provoke the destruction of the polymer matrix under UVirradiation. [ABSTRACT FROM AUTHOR]

We have synthesized large scale, thin, transparent graphene oxide (GO) flakes by Hummer’s method and investigated their suitability for fabrication of transparent nanocomposites. The GO flakes were comprehensively characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), Raman spectroscopy and Differential Scanning Calorimetry (DSC). X-ray diffraction displayed the peak of graphene oxide at 9°degree, which is characteristic peak of GO in agreement with the literature results. Scanning Electron Microscopy images revealed that thin, transparent, flake form GO with 14,8 µm lateral size and 0,31µm thickness were synthesized. The comparison with literature results show that for the first time, our group could synthesize large scale, thin and more transparent GO flakes by simple Hummer’s method using simple dispersed graphite. EDX measurements indicate the formation of layered structure with oxygen containing functional groups. The intensity ratio between D and G peaks in the Raman spectra proves that less defective GO flakes have been synthesized. The solution ability of the synthesized material indicate that high quality GO flakes were synthesized, which make them effective soluble material due to oxygen containing groups formed on the graphene plane during synthesis process.DSC results shows that these flakes are thermally stable till 200°C. Due to high solubility properties, large scale and transparency they can be very useful in fabrication of high optical transparent nanocompoties for replacement indium tin oxide transparent conductors in solar panels, biomedical applications and microwave absorbers for electromagnetic interference (EMI) environmental protection.

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