ABSTRACT
Hierarchical nanostructures play an important role in environmental clean-up and sustainability applications. The magnetic and photocatalytic characteristics of flower-like Mn-doped α-Fe2O3 nanostructures were prepared by using a polyol-assisted hydrothermal method. Crystallite sizes are in the range of 35-42 nm, and the existence of 3D hierarchical nanostructures was observed in FESEM pictures. The optical band gap energy varies between 2.08 and 2.16 eV, while XPS examination exposes the ions' charge states and validates Mn3+ inclusion in the Fe3+ lattice. At room temperature, the addition of Mn to α-Fe2O3 results in a spin disorder ferromagnetism and coercivity of about 600 Oe was achieved. Methylene blue (MB) dye solution degraded by 92% when 2.5% Mn doped with α-Fe2O3 under visible conditions for 120 min irradiation time.
ABSTRACT
Vanadium-doped α-Fe2O3 nanoparticles (VFO nanoparticles) were prepared by polyol-assisted hydrothermal method. The impact on the structure, optical, magnetic and photocatalytic properties of α-Fe2O3 nanoparticles were studied by varying the vanadium concentration from 1 to 5%. XRD analysis confirms the presence of hematite phase with hexagonal structure and estimates the nanocrystals size as â¼26-38 nm. FESEM and TEM reveal the formation of 3D flower-like morphology bundled with 2D nanoflakes. The estimated band gap energy was in the range 2.01 eV-2.12 eV. XPS study shows the presence of vanadium in V4+ oxidation state in VFO nanoparticles. VSM study shows a non-saturated hysteresis loop with weak ferromagnetic behavior for all the VFO nanoparticles. 5% V doped α-Fe2O3 nanoparticles (5%VFO nanoparticles) exhibited superior visible light driven photocatalytic activity compared to other samples.
Subject(s)
Nanoparticles , Vanadium , Light , Nanoparticles/chemistry , Polymers , Vanadium/chemistryABSTRACT
The research on extracellular matrix (ECM) is new and developing area that covers cell proliferation and differentiation and ensures improved cell viability for different biomedical applications. Extracellular matrix not only maintains biological functions but also exhibits properties such as tuned or natural material degradation within a given time period, active cell binding and cellular uptake for tissue engineering applications. The principal objective of this study is classified into two categories. The first phase is optimization of various electrospinning parameters with different concentrations of HAP-HPC/PLA(hydroxyapatite-hydroxypropylcellulose/poly lactic acid). The second phase is in vitro biological evaluation of the optimized mat using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay for bone regeneration applications. Conductivity and dielectric constant were optimized for the production of thin fiber and bead free nanofibrous mat. With this optimization, the mechanical strength of all compositions was found to be enhanced, of which the ratio of 70:30 hit a maximum of 9.53 MPa (megapascal). Cytotoxicity analysis was completed for all the compositions on MG63 cell lines for various durations and showed maximum cell viability on 70:30 composition for more than 48 hrs. Hence, this investigation concludes that the optimized nanofibrous mat can be deployed as an ideal material for bone regenerative applications. In vivo study confirms the HAP-HPC-PLA sample shows more cells and bone formation at 8 weeks than 4 weeks.
