Preparation of novel 2-(2-oxo-2H-chromen-4-yl)-3- arylthiazolidin-4-one derivatives using an efficient ionic liquid catalyst

An eco-friendly procedure for synthesis of 2-(2-oxo-2H-chromen-4-yl)-3-arylthiazolidin-4-one derivatives by three-component reaction of 2-oxo-2H-chromene-4-carbaldehydes, aromatic amines and thioglycolic acid, with tetramethylbutane-1,4-diammonium acetate as a low-cost ionic liquid catalyst under reflux condition is described. The use of an ionic liquid as a catalyst has the advantages of high yields, short reaction time and environmentally friendly reaction media.     

Green chemistry preparation of MgO nanopowders: efficient catalyst for the synthesis of thiochromeno[4,3-b]pyran and thiopyrano[4,3-b]pyran derivatives

A mild and efficient method for the synthesis of thiochro meno[4,3-b]pyran and thiopyrano[4,3-b]pyran derivatives using MgO nanopowders as a catalyst is described. The MgO nanopowders were prepared via a green biosynthesis method using an extract of Rosmarinus officinalis leaves and were characterized by Field Emission Scanning Electron Microscopy and X-ray diffraction analyses.     

MnO2/Cr2O3/PANI nanocomposites prepared by in situ oxidation polymerization method: Optical and electrical behaviors

Metal oxide–polyaniline (PANI) nanocomposite with spherical morphologies were prepared in a one-pot oxidation–reduction method via various salts as reactive oxidants. Aniline monomers polymerize as a shell on the surface of one-pot prepared metal oxides, when the aqueous solutions of aniline, a free-radical oxidant, and/or a metallic salt were exposed together. The particle size and morphology of as-prepared narrowly dispersed PANI nanocomposites were revealed by field emission scanning electron microscope images. Fourier transform infrared spectra of nanocomposites indicate that the PANI exists in the emeraldine form. The ultraviolet–visible analysis not only shows PANI is in the emeraldine form, but also indicates modified optical properties of PANI in the composite form. The hypsochromic shift of the n–π* and polaron transitions of PANI reveals the incorporation of PANI by metal oxides. The direct current (dc) electrical conductivity (σ) of as-prepared nanocomposites was measured by a four-probe method in the room temperature. Compared to PANI nanoparticles, the electrical conductivity of the composites increased with the presence of metal oxides in the nanocomposites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47219.     

MgO-CeO2 nanocomposite: efficient catalyst for the preparation of 2-aminothiophenes and thieno[2,3-d]pyrimidin-4(3H)-one derivatives

MgO-CeO₂ nanocomposite was prepared by a co-precipitation method and characterized by X-ray diffraction (XRD), FE-SEM, and particle size distribution analysis. The XRD pattern shows the cubic phase of cerium oxide as the dominate phase. FE-SEM images show the homogeneity distribution of magnesium and cerium oxides in the sample. The mean particle size of nanocomposite determined by the dynamic light scattering technique is 66?nm. The catalytic activity of MgO-CeO₂ nanocomposite was examined on the synthesis of 2-aminothiophenes and thieno[2,3-d]pyrimidin-4(3H)-one derivatives. In all cases, products were obtained in good to excellent yields.     

The Effect of NaY nano-Zeolite on the Mechanical Properties of Silicon Insoles

Silicon - The chemical composition of the insoles inbounded materials influences some of the mechanical properties of silicon insoles including; tensile strain and modules and moisture adsorption...