Wet ball milling of niobium by using ethanol, determination of the crystallite size and microstructures

This study investigates the effect of using ethanol as the process control agent during the wet ball milling of niobium (Nb). Dried nanocrystal Nb powders, of high purity, with particle sizes, ranging from 8.5 to 14.3 nm, were synthesized by ball milling. Commercial Nb powder of particle sizes of − 44 µm was employed by using the planetary ball mill equipped with stainless still vials with still balls in ethanol. A ball-to-powder mass ratio of 10:1 was used at a rotation speed of 400 rpm, an interval of 15 min with an interval break of 5 s, and a milling time of 10 h. The powder was dried in vacutec at a temperature of 100 °C, using a speed of 15 rpm in the vacuum of 250 mbar at a time of approximately 653 min. The crystal phase of the dried powders was analyzed using X-ray diffraction (XRD) with CuKɑ radiation, and by modification of the Scherrer equation, a single crystallite size of 11.85 nm was obtained. The morphology of the particles was observed using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). The XRD results show that the pure crystal sizes in nanometre (nm), which decreases as the 2θ and the full width at half maximum (FWHM) increases.

CHCl3-Dependent Emission Color and Jumping Behavior of Cyclic Chalcone Single Crystals: The Halogen Bond Network Effect

As a conventional strategy to modulate the structure and properties of inorganic single crystals, hydration/solvation is rarely found to function in pure organic single crystal. Herein, we report chalcone single crystals with CHCl3-dependent emission color and jumping behavior. Two crystals: a pure crystal phase (1) with green-yellow emission and a CHCl3-containing co-crystal phase (1•2CHCl3) with orange-red emission were constructed by fine-controlling the crystallization conditions. The special halogen bond network in the crystal packing structure effectively narrows the bandgap and thereby redshift the emission of 1•2CHCl3. 1•2CHCl3 would revert to 1 together with emission color change when losing CHCl3. These findings are similar to the effect of H2O in hydrated inorganic crystals. Notably, owing to a special pre-organized “molecular pair” structure for [2 + 2] cycloaddition, the pure crystal phase 1 exhibits violently photo-induced jumping phenomenon, indicating large potentials in intelligent devices. This work would overturn the previous perception that the structurally simple solvent molecules without conjugation cannot greatly affect the structure and properties of pure organic single crystals and provide a new strategy to construct multi-colored organic fluorescent crystals.

Об изотропных точках в примесных кристаллах K-=SUB=-2-=/SUB=-SO-=SUB=-4-=/SUB=-

The temperature, spectral and pressure dependences of the birefringence Δni of potassium sulfate crystals doped with 1.7% of copper have been studied. The introduction of the impurity is found to change the absolute value of Δni and lead to an increase in the temperature dependence of Δnі(Т). It is shown that the isotropic points appear in the doped crystal of potassium sulfate, and are shifted, compared with a pure crystal, towards low temperatures by 5 K and 11 K, respectively. It was established, that uniaxial stresses change the magnitude of the Δni absolute values, as well as the region of existence of the isotropic state. Generalized temperature-spectral-baric diagrams of the isotropic state of doped potassium sulfate crystal are constructed, making it possible to use them as a crystal-optical sensor.

Purification of Amoxicillin Trihydrate in the Presence of Degradation Products by Washing Method

Repeated crystallization or the use of different chemicals to obtain a pure crystal can cause yield/purity issues. Therefore, impurity penetrating the crystalline mesh should be removed as much as possible...

Microwave Assisted Synthesis of BenzilideneBenzylamine and Its Acetylcholinesterase and Butyrylcholinesterase Activity

BenzilideneBenzylamine the derivative of Schiff bases contain azomethine group already used widely for industrial purposes and have wide range of biological activities. Benzilidene Benzylamine were synthesized by microwave irradiation reacting different aromatic and aniline purified pure crystal, 85% yield obtained reaction monitor by TLC. The Anticholinesterase activity utilized spectrophotometric Ellman assay for determination of butyrylcholinesterase and acetylcholinesterase. The synthesis compound 1 – 6 showed a wide range of inhibitory activity the compound 3((E)-N-(4-fluorobenzylidene)aniline) at 1000µg/mL, 71.62±0.74 percent inhibitory acetylcholinesterase potential while compound 6 ((E)-4 ((phenylimino)methyl) benzaldehyde) at 500 and 1000 µg/mL at IC50 show 71.68±0.22, 77.84±0.32 percent inhibitory potential comparatively greater than standard Galanthamine at 62.5µg/mL, 74.10±0.90 at IC50. The butyrylcholinesterase activity of compound 6 ((E)-4 ((phenylimino)methyl)benzaldehyde) at 1000 µg/mL, show 75.83±1.07 percent inhibitory potential which is similar to standard compound at 62.5µg/mL concentration of 75.45±0.90 percent butyrylcholinesterase inhibitory activity.

Tight binding model of induced band shift in CoO nanoparticles

Recently researchers have shown that water splitting occurs in 6 nm particles of Co-O, an effect not seen in the pure crystal, indicating that the band shift in these particles is probably due in part to surface modification. Others have shown that band edges in metal oxide crystals can be shifted up by induced dipoles on the surface. These are created by attaching polar molecules or passive ligands. Here we present a tight binding model that predicts that the observed band shift in Co-O is caused by the formation of local dipole moments, which result from dangling bonds on a distorted surface coupled to attached water molecules. Holding the bond distances fixed, we show that this effect occurs at a variety of bond angles. We show that the most probable angle is [Formula: see text], implying that this technique can be applied to the study of amorphous surfaces.

The introduction of a perovskite seed layer for high performance perovskite solar cells

A compact seed perovskite layer (CSPL) with a p–i–n planar heterojunction structure for perovskite solar cells achieved a 19.24% power conversion efficiency with a record open circuit voltage of 1.16 V and 20.37% PCE was achieved with a CSPL assisted n–i–p structure in a pure crystal perovskite film. The CSPL assists vertical growth of the perovskite crystal to enhance device performance.