Materials Discovery最新文献

This paper discusses, the nanometric size effects, including intrinsic factors such as structure, the nature of A-site ion substitution, B-site ions, on the redox properties of nanometric La_1−xK_xFeO₃, La_1−xK_xCoO_3, La_1−xNa_xMnO₃, La_1−xK_xMnO₃, perovskite-type oxide catalysts. The external factors of catalyst and soot particulate, the content of NO and O₂ and the ratio of catalyst and gas flow rate on the catalytic activity for the simultaneous removal of NO_X and soot particulates were systematically investigated. The catalysts were characterized by means of SEM, EDX, XRD and FT-IR and the catalytic potential for the simultaneous removal of nitrogen oxides (NOx) and diesel particulate matter (soot) were evaluated by temperature-programmed oxidation reactions. The entire catalyst samples obtained the perovskite structure, with high activities for the simultaneous elimination of soot and NO_X. Alternatively, the number of surface atoms is much higher than the normal bulk catalysts and the size of the nanoparticle is also smaller. These characteristics are beneficial for the adsorption and activation of reactant molecules including NO or O_2, or even soot particle.

The present work describes the fabrication of metal matrix composite (MMC) using the stir casting method with Aluminum as a base metal and-, silicon carbide and copper as the reinforcements. The wear behavior of Al-SiC-Cu MMCs for varying reinforcement contents, loads, sliding speeds, and distances were evaluated using a “pin on disk” apparatus, and using a L27 Taguchi orthogonal array. The optimal combination of reinforcement content, load, sliding speed, and distance was obtained using gray relation analysis (GRA) and Taguchi for minimum wear. It was concluded from scanning electron microscopy (SEM) that the nature of wear was mostly abrasive.

Chitin whiskers reinforced Poly(acrylicacid) films were prepared by casting. Films were characterised for mechanical and thermal properties. Raman and XRD spectrum and SEM morphology were examined. The tensile strength increased as chitin increases up to 11.39% and gradually decreases. The % strain gradually reduces as whiskers increases. Thermal stability of films improved from those of the pure PAA as the Tg increases at higher whiskers content. The strongest interaction between the carboxylic (CO) group of PAA and the amide (NH3+) of chitin at the amorphous phase occurs at 3.23% whiskers. The particle size of chitin was reduced as revealed by XRD.

We report the fabrication of multi-mineral (Mg, Sr, Zn = MM) substituted apatite (HA) (MMHA) nanoparticles with different morphologies, which were successfully synthesized by a method based on precipitation of MMHA precursor in different natural deep eutectic solvents (NADES). Chemical structures were identified by FTIR, XRD and the crystal morphology was analyzed by SEM and TEM. The results reveal that the morphology of MMHA can be effectively controlled by the viscosity of NADES solvents.

The effectiveness of expired Tramadol (ETr) as a corrosion inhibitor for mild steel in 1 M HCl solution was tested by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), surface analysis (SEM and AFM), and density functional theory (DFT) methods The data obtained from EIS and PDP curve indicated the inhibition efficiency is in direct relationship to Tramadol concentration. The Langmuir adsorption isotherm data confirms a physiochemical mechanism. The SEM and AFM analyses reveal a smoother surface of mild steel. The DFT calculations were used to evaluate the electronic parameters of the neutral and protonated forms of the drug.