Enhanced electrical and magnetic functionality of Ni-Zn-co-doped CoFe2O4 rGO nanocomposites.

Enhancement in electrical and magnetic functionalities of rGO CoFe2O4 and Co0.7Zn0.3Fe1.7Ni0.3O4 nanocomposites was identified compared to their spinel-type metal oxides. Moreover, changes in morphology that occurred during the formation of the composites were fabricated via a simple in situ hydrothermal route. Electron microscopic investigations confirmed that the microspheres of the metal oxides were constructed by porous nanolamellae comprising nanoparticles interconnected to form highly stable porous microspheres. Conversely, in rGO-CoFe2O4 and rGO-Co0.7Zn0.3Fe1.7Ni0.3O4 composites, distorted spinel-type metal oxide spheres on rGO sheets were observed. Frequency-dependent conductivity increased with an increase in temperature, obeying Jonscher's power law and Koop's phenomenological theory. The resistance of ferrites decreased from ∼1.4 MΩ to 30 KΩ for their respective rGO-based nanocomposites. The hysteresis curves of all the compounds showed them to be isotropic, soft ferrimagnetic in nature. Furthermore, a 30-50% enhancement in the values of magnetic parameters of the ferrites occurred when they were interfaced with rGO sheets. This enhancement was probably due to the interfacial interaction of rGO with ferrites. Such enhancement may afford an advancement in the potential applications of these nanocomposites.

Regulation of Nitric Oxide (NO) Release by Membrane Fluidity in Ruthenium Nitrosyl Complex-Embedded Phospholipid Vesicles.

Incorporating water-insoluble nitric oxide (NO)-releasing molecules into biocompatible vesicles may allow for the tunable control of NO release on a specific target site. In vesicles, membrane fluidity plays an important role and influences the final therapeutic efficiency of drugs loaded into the vesicles. Hence, we aimed to investigate the effect of lipid fluidity on the NO release behavior of the photo-controllable ruthenium nitrosyl (Ru-NO) complex. In this regard, a new photoactive ruthenium nitrosyl complex (L.Ru-NO) with amphiphilic terpyridine ligand was synthesized and characterized in detail. L.Ru-NO was incorporated with commercial phospholipids to form nanoscale vesicles L.Ru-NO@Lip. The photoactive {Ru-NO}6 type complex released NO in the organic solvent CH3CN and aqueous liposome solution by irradiating under low-intensity blue light (λ = 410 nm, 3 W). To demonstrate the effect of lipid structure and fluidity on NO release, four different liposome systems L.Ru-NO@Lip1-4 were prepared by using phospholipids such as DOPC, DSPC, DPPC, and DMPC having different chain lengths and saturation. The NO-releasing abilities of these liposomes in aqueous medium were studied by UV-vis spectrum, colorimetric Greiss, and fluorescent DAF assay. The results show that the rate of NO release could be easily tuned by varying the lipid fluidity. The effect of temperature and pH on NO release was also studied. Further, the complex L.Ru-NO and liposomes L.Ru-NO@Lip1 were assayed as an antibacterial agent against the strains of bacteria Escherichia coli and Staphylococcus aureus.

Multifunctionality exploration of NiCo2O4-rGO nanocomposites: photochemical water oxidation, methanol electro-oxidation and asymmetric supercapacitor applications.

Different weight percentages of NiCo2O4-rGO nanocomposites were prepared via a facile hydrothermal method. The prepared nanocomposites were structurally and morphologically characterized by X-ray diffraction, Raman spectroscopy, and electron microscopy. The structural studies show the formation of rGO-NiCo2O4 nanocomposites by embedment of porous NiCo2O4 rods on rGO sheets. The effect of the NiCo2O4 content on photochemical water oxidation was investigated. It revealed that the catalysts NiCo2O4-rGO with 1 : 26 ratio (NCO26) and 1 : 13 ratio (NCO13) are efficient in generating oxygen under light illumination. It proves that NCO26 works far more effectively as a photocatalyst compared to NCO13. Methanol electro-oxidation of the NCO26 nanocomposite shows a current density of 24 mA cm-2 at a potential of 0.45 V in cyclic voltammetry and maintains the current for 3600 s at 0.45 V in chronoamperometry. An onset potential of 0.344 V was observed for 0.5 M methanol oxidation. The specific capacitance values were found to be 354.75 F g-1 and 375.32 F g-1 at 1 mV s-1 and 1 A g-1, respectively, for NCO26 in supercapacitor studies. The charge stored via capacitive and diffusion-controlled processes was determined using Power's law and Trasatti plot. An asymmetric supercapacitor device shows a specific capacitance of 122.2 F g-1 at a current density of 1 A g-1 and exhibits a retention of 74.3% after 5000 cycles. An energy density of 67.89 W h kg-1 and a power density of 1 kW kg-1 at a current density of 1 A g-1 are observed.

In-Vitro Study of Sol Gel Synthesized Bioactive Glass Ceramics for Anti-Microbial Properties.

In this research work new type of bioglass ceramics successfully synthesized the bioglass composition: 50SiO2-30CaO-10P2O5-10MgO by sol-gel technique which was further heated up to 600 °C. Different characterization techniques were applied on the prepared bioglass powder to obtain the structural information. X-ray powder diffraction (XRD) and fourier-transform infrared spectroscopy (FTIR) analysis confirms the amorphous nature and apatite formation on surface of the sample. The time dependent biological activity was tested on immersed samples with simulated body fluid (SBF). Structural configuration of the hydroxyapatite layer along with nano-size as well as texture properties of the samples were confirmed using field emission scanning electron microscope (FE-SEM), high-resolution transmission electron microscopy (HR-TEM) and Brunauer-Emmett-Teller (BET) techniques, respectively. It was found that magnesium performs a pivotal role in bone proliferation and improves the thermophysical properties of the synthesized bioglass ceramics. The antibacterial effects were studied by two well-known pathogen Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

Inorganic frameworks from selenidotetrelate anions [T2Se6]4- (T = Ge, Sn): synthesis, structures, and ionic conductivity of [K2(H2O)3][MnGe4Se10] and (NMe4)2[MSn4Se10] (M = Mn, Fe).

Syntheses, structures, and physical properties of three inorganic framework compounds [K(2)(H(2)O)(3)][MnGe(4)Se(10)] (1), (NMe(4))(2)[MnSn(4)Se(10)] (2), and (NMe(4))(2)[FeSn(4)Se(10)] (3) are presented. The title compounds are based on a prominent open framework anionic structure; in these cases, however, they contain K(+), the smallest type of counterion to be included so far (1), or represent Sn analogues (2, 3). Both changes with respect to related compounds are reflected in peculiar physical properties, such as ion conductivity or relatively small band gaps.

Bioactivity of electro-thermally poled bioactive silicate glass.

A 45S5 bioactive glass (nominal composition: 46.1 mol.% SiO2, 2.6 mol.% P2O5, 26.9 mol.% CaO, 24.4 mol.% Na2O) was electrothermally poled by applying voltages up to 750 V for 45 min at 200 degrees C, and the thermally stimulated depolarization currents (TSDCs) were recorded. Changes in chemical composition and electrical properties after poling were investigated by TSDC measurements, impedance spectroscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). The poling led to the formation of interfacial layers underneath the surface in contact with the electrodes. Under the positive electrode, the layer was characterized by Na+ ion depletion and by a negative charge density, and the layer was more resistive than the bulk. The influence of poling on the bioactivity was studied by immersion of samples in simulated body fluid (SBF) with subsequent cross-sectional SEM/EDX and X-ray diffraction analysis. It was found that poling leads to morphological changes in the silica-rich layer and to changes in the growth rate of amorphous calcium phosphate and bone-like apatite on the glass surface. The bone-like apatite layer under the positive electrode was slightly thicker than that under the negative electrode.