Design of Zn1-xCuxO Nanocomposite Ag-doped As An Efficient Antibacterial Agent

This study aims at the preparation of antimicrobial nanoparticles hybrid based on silver (Ag) doped Zn1-xCuxO. Zn1-xCuxO nanocomposite Ag-doped prepared via wet chemical route, co-precipitation, and impregnation method, respectively. The inclusion of silver in the nanocomposite did not change its structure. However, the insertion of CuO into the ZnO structure has no impact due to the similarity of Cu ion radius with Zn ion radius (0.74 toward 0.73 Å). Hybrid nanomaterials characterized by XRD, FT-IR, and FESEM technique. The effect of loading of CuO nanoparticles into ZnO nanomaterials investigated on their antimicrobial behavior. For this purpose, CuO with a variety ratio doped on the ZnO nanoparticles, and then Ag entrapped by impregnation methods. Minimum inhibitory concentration (MIC) measurements were carried out to measure the antimicrobial behavior of ZnO(Ag) and mixed hybrid Zn1-xCuxO(Ag) towards gram-negative and gram-positive bacteria and fungus. gram-positive and gram-negative bacteria were generally more sensitive to ZnO and CuO nanoparticles, respectively. Then, these hybrid nanomaterials can be an excellent candidate for both gram-positive and gram-negative bacteria.

Effect of Transition Metal Substitution on the Charge-Transfer Phase Transition and Ferromagnetism of Dithiooxalato-Bridged Hetero Metal Complexes, (n-C3H7)4N[FeII1−xMnIIxFeIII(dto)3]

The dithiooxalato-bridged iron mixed-valence complex (n-C3H7)4N[FeIIFeIII(dto)3] (dto = dithiooxalato) undergoes a novel charge-transfer phase transition (CTPT) accompanied by electron transfer between adjacent FeII and FeIII sites. The CTPT influences the ferromagnetic transition temperature according to the change of spin configuration on the iron sites. To reveal the mechanism of the CTPT, we have synthesized the series of metal-substituted complexes (n-C3H7)4N[FeII1-xMnIIxFeIII(dto)3] (x = 0–1) and investigated their physical properties by means of magnetic susceptibility and dielectric constant measurements. With increasing MnII concentration, x, MnII-substituted complexes show the disappearance of CTPT above x = 0.04, while the ferromagnetic phase remains in the whole range of x. These results are quite different from the physical properties of the ZnII-substituted complex, (n-C3H7)4N[FeII1-xZnIIxFeIII(dto)3], which is attributed to the difference of ion radius as well as the spin states of MnII and ZnII.

Synthesis, Short-Range Structure and Hydration Processes of Oxyhalides Ba2InO3X (X = F, Cl, Br) with Ruddlesden-Popper Structure

The oxyhalides Ba2InO3F, Ba2InO3Cl, and Ba2InO3Br were synthesized using the solid state method. It was found that the increasing of halide ion radius leads to the increase of lattice parameters and also caused to redistribution of indium-oxygen bond lengths. The possibility of water uptake was proved by thermogravimetry measurements. The presence of different forms of oxygen-hydrogen groups in the structure of hydrated oxyhalides was indicated by infrared spectroscopy.

Tuning phase transitions of aqueous protein solutions by multivalent cations

Cation-specific characteristics such as ion radius and hydration effects strongly influence the phase behaviour of protein-salt solutions.

Influence of Ti addition on thermophyscial properties of Sm2Ce2O7 oxides

Sm2(Ce1-xTix)2O7 (where x = 0, 0.1,0.3, 0.5) solid solutions were synthesized by conventional solid state reaction method using Sm2O3, CeO2 and TiO2 as raw reactants. The synthesized powders were pressed into pellets by cold isostatic pressing and pressure-less sintered at 1600 ?C for ten hours. Their phase-structure and thermophysical properties were studied. The synthesized samples exhibit single defect fluorite-type structure. Due to the phonon scattering by substitutional atoms, the thermal conductivities of the Sm2(Ce1-xTix)2O7 solid solutions decrease with the increasing Ti4+ content over the entire temperature range, which are significantly lower than that of yttrium stabilized zirconia (YSZ). The thermal expansion coefficients of the prepared Sm2(Ce1-xTix)2O7 solid solutions also decrease with the increasing Ti4+ fraction, which can be attributed to the lower titanium ion radius.

The size-responsive phase transition mechanism and upconversion/downshifting luminescence properties of KLu2F7:Yb3+/Er3+ nanocrystals

With the decrease of grain size, high surface tension triggers anisotropic KLu2F7:Yb3+/Er3+ to phase transition to isotropic KLu3F10:Yb3+/Er3+ ignoring the doping ion radius.

Comparison of CNT-Papers and CNT-Arrays Regarding Their Active Behavior

This paper focuses on the actuation mechanisms of CNT-papers and CNT-arrays. CNT-papers represent architectures of CNTs which are connected by van der Waals forces or structural entanglement. In contrast CNT-arrays are vertically aligned CNTs. Single CNTs are favored for investigation of the active behavior of the hexagonal carbon structure formed by covalent C-bonds. CNT-arrays feature contiuous tubes of 3 mm length which allows the test the tubes themselves. Thus they are clamped at each end they represent samples for testing covalent bonds. Both sample types are tested within an actuated tensile test set-up under different conditions to identify the specific influence. Furthermore different electrolytes are used to investigate the influence of the ion-radius on the CNT-paper. CNT-papers are tested in water-based electrolytes CNT-arrays are tested in an ionic liquid. It was found that the performance of CNT-papers strongly depends on the conditions which indicates ion-diffusion as actuation mechanism. However, CNT-arrays are almost unaffected by the conditions, considering their active response and sample composition quantum mechanical reasons seem to be the most appropriate explanation for the array actuation.

XRD, DTA AND TGA INVESTIGATIONS OF THE BaFe12-xAlxO19 SOLID SOLITIONS

By X-ray diffraction, differential thermal analysis (DTA) and thermo-gravimetric analysis (TGA) were investigated BaFe12-xAlxO19 hexaferrites with various concentrations of Al (x = 0.3, 0.9 and 1.2). Crystal structure of compounds was determined, and it determined that under normal condition (P = 0 GPa, T = 300 K) they possess structure is hexagonal symmetry with the space group P63/mmc. Replacing Fe3+ ions Al3+ with ions, on account of reducing ion radius, decrease of indices of parameters was occurred. This crystal structure is saved in a temperature range 30 - 950 ºC and structural phase transition do not occur. Energy supplied to a system is fully swallowed by a system, monotonic decrease is occurred in TGA curve and in DTA curve endo and exo effects do not occur.