International Journal of Nanoparticles (8 papers in press)
- Role of amoxicillin functionalized Fe3O4 on the settling velocity of starch
by Shanmugam Palanikumar, Rajeshwaran Palanichamy, Balakrishnan Meenarathi, Hunghsia Chen, Pinghei Chen, R. Anbarasan
Abstract: Amoxicillin functionalized Ferrite nanoparticle was synthesized by co-precipitation method under nitrogen atmosphere. Thus obtained black colored product was characterized by fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, X-ray diffraction (XRD), particle size analysis (PSA), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and vibrating sample measurement (VSM) techniques. The sedimentation velocity of starch in the presence of Amoxicillin functionalized Ferrite was carried out at three different pH values 2.5, 7.1 and 12.0. The influence of Amoxicillin functionalized Ferrite on the sedimentation velocity of starch was evaluated with the help of FTIR, SEM, VSM, UV-visible, Fluorescence spectroscopy. We noted an important observation that Starch-Fe3O4-Amoxicillin system exhibited the lowest VSM value than the Fe3O4-Amoxicillin system.
Keywords: functionalization; ferrite; starch; amoxicillin; sedimentation.
- Non-Darcy Double Diffusive Mixed Convection for Nanofluid with Soret and Dufour Effects in a Lid-Driven cavity
by Rajarathinam Muthu
Abstract: Unsteady laminar double diffusive mixed convection in a two sided lid driven cavity filled by Cu-water nanofluid with Soret and Dufour effects have been investigated
numerically using the Darcy Brinkman Forchheimer model. Constant temperature and
concentrations are imposed at the vertical walls while the horizontal walls are perfectly insulated. The finite volume method over SIMPLE algorithm is used to solve the non-dimensional governing equations. The results are presented interms of streamlines, isotherms, isoconcentrations and heatline trajectories as well as the mid-height velocity profiles, average Nusselt number and Sherwood number graphs.
Keywords: double diffusive convection; porous medium; nanofluid; lid-driven cavity; Soret and Dufour effects.
- Electrothermo convection in a horizontal layer of rotating nanofluid
by Ramesh Chand
Abstract: Thermal instability in a horizontal layer of nanofluid with vertical AC electric field in the presence of rotation is investigated. The flux of volume fraction of a nanoparticle is taken to be zero on the isothermal boundaries and the eigenvalue problem is solved using the Galerkin method. The model used for nanofluid incorporates the effect of Brownian diffusion, thermophoresis and electrophoresis. Linear stability theory based upon the normal mode technique is employed to find expressions for Rayleigh number for stationary and oscillatory convection. The influence of rotation (Taylor number), Lewis number, modified diffusivity ratio, concentration Rayleigh number, AC electric Rayleigh number on the stationary convection have been investigated both analytically and graphically. The necessary condition for the occurrence oscillatory convection has also been obtained.
Keywords: Taylor number; Lewis number; AC electric field; Brownian motion; Prandtl number
- Biosynthesis of Nanosilver using Indian Medicinal Plants and Evaluation of their Antibacterial Activity
by Lakshmi Priya Thyagarajan, Meenambal T, Lavanyasri R, Nandhini S, Pavithra N, Swathi S, Sri Vani Uthra I
Abstract: Phytosynthesized silver nanoparticles (AgNPs) were developed from silver nitrate (AgNO3) through a simple and eco-friendly route using the aqueous extracts of Indian medicinal plants Acacia nilotica, Solanum trilobatum and Punica granatum. The AgNP formation were characterised by using UV-Visible spectroscopy, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Diffraction Analysis (XRD) and Energy dispersive X-ray spectroscopy (EDAX). The average particle size of the AgNPs synthesized from A. nilotica, S. trilobatum and P. granatum was determined to be 50, 110 and 60 nm respectively. Anti-bacterial activity studies revealed that AgNPs synthesized from P. granatum exerted maximum effect against the few pathogenic and non-pathogenic bacterial strains. Phytochemical screening of the crude extracts of the three chosen plants identified tannins to be the active component responsible for the reduction of silver ions to nanoparticles. This study also revealed that green procedure would be preferred for large scale operation with high biocompatibility.
Keywords: Silver nanoparticles; Anti-microbial activity; Atomic Force Microscopy; Scanning Electron Microscopy; X-ray Diffraction analysis; Energy Dispersive X-ray spectroscopy; AgNPs ;Tanins
- Investigations on Structural, Optical, Morphological and Electrical Properties of Nickel Oxide Nanoparticles
by sagadevan Suresh
Abstract: Nickel oxide (NiO) nanoparticles have been prepared by chemical co-precipitation method. The synthesized nanoparticles were investigated by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy and dielectric studies. The formation of NiO nanoparticles was confirmed by X-ray diffraction (XRD). The morphology and size of the NiO nanoparticles were characterized using scanning and transmission electron microscopy (SEM and TEM). The optical properties were studied by the UV-Visible absorption spectrum. The dielectric properties of NiO nanoparticles were studied in the frequency range of 50 Hz5 MHz at different temperatures. Further, electronic properties, such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the NiO nanoparticles were calculated. The AC conductivity of the NiO nanoparticles increases with increase in temperature and frequency. The activation energy was calculated from AC conductivity studies.
Keywords: NiO, XRD, SEM, TEM, UV analysis, Dielectric constant, Dielectric loss and AC conductivity studies
- Synthesis, characterization and in vitro toxicity assessment of nano iron
by Venkatachalam Deepa Parvathi, Kalyanaraman Rajagopal, Jalpan Pandya, Betty Lincoln, Ravindran Sumitha
Abstract: Metal nanoparticles have specific and dynamic applications in biomedical research and diagnosis apart from their existing application in electronics and other industries. Their novel properties make them convenient and a preferred choice for use in biomedical research. Their ability to bind to DNA strands and penetrate into vasculature /target organs specifically make them important in therapeutic applications apart from imaging and diagnosis. Clinical practice involves combination of nanotechnology, imaging techniques and biomedicine towards areas such as targeted drug delivery, tissue engineering, antimicrobial therapy, regenerative medicine and hyperthermia based treatment for neoplasia. A variety of nanoparticles which differ from each other in their physical properties( composition, coating, size, shape, surface charge and dispersion status) have been engineered and have entered production in pharmaceutical industries apart from cosmetic based and biomedical products. This generates view on risks for human health and environment and evaluation of the toxicity of such engineered nanoparticles is important. Many metal nanoparticles such as iron, iron oxide, gold, silver, nickel, copper, cobalt, magnesium etc., are gaining their thrust in biomedical research. To explore and understand the toxicity of such metal nanoparticles is essential in research. The present study includes a design to characterize nano iron synthesized by aqueous phase reduction method. Characterization tools include UV VIS spectroscopy, FTIR, SEM, SEM EDAX, TEM and XRD. The thus characterized nano iron was assessed by in vitro genotoxicity end points; namely hemolytic assay, micronucleus assay, chromosomal aberration assay and bacterial reverse mutation test. The results of these toxicity tests indicate for those concentrations employed(0.1mM, 1mM,5mM and 10mM ), did not demonstrate any mutagenic or genotoxic activity.
Keywords: Nano iron, Aqueous phase reduction method, Characterization, In vitro, Hemolytic assay, Chromosomal aberration assay, Micronucleus assay, Bacterial reverse mutation test(Ames test)
- Structural and Magnetic properties investigation of sintered MnxMg1-xFe2O4 ferrites from nanopowders prepared via co-precipitation method
by Sohrab Manouchehri, Seyed Taghi Mohammadi Benehi, Mohammad Hassan Yousefi, Javad Zahmatkesh, Mohsen Abdollahi
Abstract: Nanoferrite powders having composition MnxMg1-xFe2O4 (x= 0.0, 0.2, 0.4, 0.6, 0.8) were synthesized by the chemical co-precipitation method and then sintered as the pellets. The X-ray diffraction (XRD), Alternating Gradient Force Magnetometer (AGFM) techniques and Curie temperature measurement were used to carry out this study. The XRD patterns confirm the nanosized dimension of the samples and showed that the samples are single phase cubic spinel nanoferrites. From the analysis of XRD data using Scherrers formula, the average crystallite size (DXRD) of the particles was found to decrease from 81 to 55 nm with increasing manganese substitution. Substitution of Mn2+ in MgFe2O4 causes an increase in the lattice constant (a) from 8.35 to 8.43
Keywords: Nanoferrite powders; Co-precipitation method; Sintering; Spinels; Magnetic properties
- Synthesis and Microstructure of Gallium Substituted Cobalt Ferrite Nanoparticles by Hydrothermal Method
by Gayathri Sivaraman, Kalainathan sivaperuman
Abstract: Magnetic CoFe2-xGaxO4 nanoparticles were successfully synthesized via hydrothermal method. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM).The experimental results showed that the CoFe2-xGaxO4 were composed of single phase spinel structure and the average crystallite size is between 42 and 57nm.The saturation magnetization (Ms) of the CoFe2-xGaxO4 nanoparticles decreased linearly as the contents of Ga increased for x = 0.2 -0.8 which can be used in sensor applications.
Keywords: Magnetic Nanoparticles;Hydrothermal method;FESEM;HRTEM;VSM magnetic studies.