Realization of structural transformation for the enhancement of magnetic and magneto capacitance effect in BiFeO3-CoFe2O4 ceramics for energy storage application.

In this study, (1 - x) BFO-xCFO (CFO, x = 0.00, 0.05, 0.10 and 0.30) ceramics were synthesized by a solid-state reaction method; their compositions were driven by structural, microstructural, vibrational, electrical, magnetic properties; their enhanced magneto capacitance (MC) effect have also been carried out. Reitveld refinement studies of X-ray diffraction data shows composition-driven structural phase transformation from rhombohedral (R3c) to tetragonal (P4mm). Two phonon scattering Raman modes were observed for the higher wavenumber which supports the crystal structural transition in the BFO-CFO. Ferroelectric polarization shows that the polarization increased with increasing CFO concentration, which describes the changes of the polar symmetry of the crystal structure from rhombohedral (R3c) to tetragonal (P4mm). In Further, the maximum efficiency of energy density (η = 68.65%), reversible energy density of 0.138 J/cm3 and the strong magneto capacitance was observed in 0.9BFO-0.1CFO, which belongs to the morphotropic phase boundary (MPB) region near to the BiFeO3-rich region. The magnetic response analysis has shown, the saturation magnetization (Ms) values of 83 emu/gm and 139 emu/gm for pure CFO and 0.7BFO-0.3CFO composite, respectively, and their magnetic behaviours were also confirmed with Arrott-Belov-Kouvel (ABK) plot.

Biomolecule chitosan, curcumin and ZnO-based antibacterial nanomaterial, via a one-pot process.

As a result of the existence of drug-resistant bacteria and the attendant deficiency of innovative antibiotics, the therapeutic and the clinical sectors are, continually, in search of appropriate multifunctional nanomedicines. Herein, curcumin-chitosan-zinc oxide (CCZ) was successfully synthesized by a one-pot method. Transmission electron micrograph reveals that curcumin and chitosan were layered on a hexagonal ZnO and the particles are sized to ∼48 ±2nm. X-ray diffractogram confirmed the formation of CCZ crystal structure. The photoluminescence spectra of CCZ, shows blue and green emissions at 499 nm and 519 nm, respectively, due to the active radicals generated in the nanomaterial, which are responsible for the associated antimicrobial and anticancer activities. The antibacterial activity of the CCZ, performed against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), showed a greater antibacterial effect than the commercial amoxicillin. The cytotoxic effect of the CCZ nanomaterial was examined in cultured (MCF-7) human breast cancer cells. An IC50 concentration value of 43.53 µg/mL, was recorded when evaluated after 24 h of CCZ with the MCF-7 cell line. From this study, it is believed that CCZ is a highly promising nanomaterial, which will be suitable for advanced clinical applications.

Facile synthesized novel hybrid graphene oxide/cobalt ferrite magnetic nanoparticles based surface coating material inhibit bacterial secretion pathway for antibacterial effect.

Nanomaterial based paints are in current demand in the area of surface protective coatings due to the significant advances made to improve their antibacterial and anticorrosion characteristics. In this work, we have developed magnetic graphene oxide (MGO) paint with the incorporation of cobalt ferrite (CF) and graphene oxide (GO) along with paint materials by using high energy ball milling (HEBM). Morphological, elemental and functional analysis of the MGO paint is studied with ESEM, AFM, Raman, FTIR spectroscopy. EDS and PIXE methods are used for elemental analysis. Thermal analysis shows that the MGO film was stable up to 100 °C. The saturation magnetization of CF MNP is observed as 76 emu/g and it is reduced to 12 emu/g for MGP paint. The detailed antibacterial study of the prepared MGO paint has performed with S. typhimurium and E. coli. The dead-live assessment shows the dead population for S. typhimurium is superior up to 82% whereas it is 20% for E. coli. The morphological damage of bacterial cells is studied using SEM technique. Flow cytometry analysis of reactive oxygen species (ROS) generation experiments and computational analysis supported the proposed mechanism of induced ROS for the damage of bacterial membrane via interaction of GO and CF with bacterial proteins leading to alteration in their functionality. The observed results indicate that the prepared MGO paint could be a better candidate in the area of nano paint for surface protective coatings.