International Journal of Nano and Biomaterials (21 papers in press)
Silver Nanoparticles from Methanolic Stem Extract of Gymnema Sylvestre and its Characterization Studies
by Sathyaa R, Subha V, Ernest Ravindran R S, Renganathan S
Abstract: In this approach silver nanoparticles (AgNPs) were synthesized from Gymnema sylvestre stem extract. Gymnema sylvestre herb exhibits wide range of therapeutic properties. Phytochemical studies of this plant extract revealed the presence of alkaloids, flavonoids, tannins and glycosides. These phyto constituents were responsible for the reduction of silver ions to silver nanoparticles. The bioreduced silver nanoparticles were characterized by UV-visible spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), X-Ray powder Diffraction (XRD) and High Resolution Transmission Electron microscopy (HR-TEM). The free radical scavenging activity of stem extract of Gymnema sylvestre was also evaluated using DPPH assay. DPPH radical scavenging ability of Gymnema sylvestre stem extract was found to be 56.25 %. Antimicrobial activity of these silver nanoparticles was examined through disc diffusion method. Zone of inhibition formed against silver nanoparticles at different concentrations 30, 60, 100
Keywords: Phytochemical; Antimicrobial activity; Gymnema sylvestre; Silver Nanoparticles.
Analytical modelling of sensing performance of carbon nanotubes for gas sensing
by Geoffrey Ijeomah, Fahmi Samsuri, Mohamad Adzhar Md Zawawi
Abstract: Carbon nanotubes as a new variety of quasi one-dimensional (1D) materials belong to the family of carbon-based nanostructures, which have recently ignited tremendous research interest. The latest discoveries of the outstanding properties of carbon nanotubes (CNTs) in terms of their electronic and structural behaviours such as, large surface-to-volume ratio, tunable band gap, high mechanical strength, high mobility and extreme sensing capability make them a great candidate for nanoelectronic devices of the future. Due to the importance of nanoscale sensors and biosensors in various areas of our lives, using promising materials such as carbon nanotubes has widely captured the attention of researchers to achieve better sensitivity and accuracy in these devices. Up until now, the majority of investigations have focused on experimental studies for sensors. Therefore, there is a lack of analytical models in comparison to experimental investigations. In order to model the transport parameters of a CNT-based gas sensor, the field effect transistor (FET)-based structure has been employed as a primary model for a gas detection sensor. The conductance of the carbon nanotube has been affected under exposure to the target analyte NH3 gas molecules. The absorption of NH3 gas concentration on the CNT surface follows a chemical reaction between CNTs and the NH3 gas. Therefore, it modulates the current-voltage (I-V) characteristics and conductance of the proposed CNT-based gas sensor. The I-V characteristics of the CNT-based sensors have been proposed as a criterion to detect the effect of gas absorption. Finally, the accuracy of the proposed models were validated by benchmarking them on existing experimental works.
Keywords: carbon nanotubes; sensors; I-V characteristics; conductance.
Modifications of optical properties in doped germanene nanosheet
by Namrata Dhar, Debnarayan Jana
Abstract: Optical properties, like complex dielectric constant, absorption
coefficient, refractive index and reflectivity have been analyzed via density
functional theory (DFT) of As and Ga doped free standing (FS) germanium (Ge)
nanosheet. Position dependent (same or different sub-lattice positions) doping
mechanism of foreign elements along with concentration variation upto 6.25%,
in pristine germanene layer has been adopted for the whole work. Interesting
modifications in optical anisotropy than pristine layer have been observed as
a consequence of doping. Such modifications, like enhancement or reduction
of peak intensity or shifting of peak positions may be useful to design smart
germanene based opto-electronics devices in upcoming future.
Keywords: Germanene; Density functional theory; Optical properties.
Thin film of Yttria stabilized Zirconia on NiO using vacuum cold spraying process for solid oxide fuel cell
by Debabrata Pradhan, Lala Behari Sukla
Abstract: Yttria stabilized zirconia (YSZ) was fabricated on a glass and NiO-YSZ anode support substrate using the vacuum cold spraying (VCS) technique at room temperature. The field emission scanning electrode microscope (FESEM) analysis revealed a dense microstructure and several vertical cracks within 0.1 μm width of the YSZ film. The transmission electron microscopy (TEM) was used to analyze the grain size and it was found to be 20 nm which was finer size compared to the average particle size of the starting YSZ powder. The x-ray diffraction (XRD) analysis showed lacking of phase transformation during the VCS process. The YSZ film fabricated by VCS technique showed better gas tightness compared to that fabricated by atmospheric plasma spray process. The Youngs modulus of the YSZ film was found to be 172 GPa.
Keywords: Yttria stabilized zirconia; vacuum cold spraying; solid oxide fuel cell; thin film; gas permeability; conductivity; mechanical properties.
Synthesis and Characterization of Lanthanum Complex Bis (5-Choloro-8hydroxy quinoline)(2-2bipyridine) Lanthanum La(Bpy)(5-Clq)2
by Rahul Kumar, Ankur Soam, Parag Bhargava
Abstract: Lanthanum complex Bis (5-Choloro-8hydroxyquinoline) (2-2bipyridine) lanthanum La(Bpy) (5-Clq)2 has been synthesised and characterized for its structural, thermal and photoluminescence analysis. Structure analysis of the complex was performed by Fourier transformed infrared spectroscopy (FTIR). Thermal analysis of the lanthanum complex was done by thermal gravimetric analysis (TGA) and complex is stable up to 370 oC. Absorption and emission spectra of the complex was measured by UV-visible spectroscopy and photoluminescence spectroscopy, respectively. Solution of this complex in ethanol showed two absorption peaks at 402 and 334 nm, which may be attributed due to (π π*) transitions. The photoluminescence spectra of La(Bpy)(5-Clq)2 in ethanol solution showed intense peak at 510 nm.
Keywords: Organometallic compounds; Lanthanum complex; Chemical Synthesis; Thermal stability; Photoluminescence.
Effect of annealing on the physical properties of WO3 thin films
by Madhuri Kalapala
Abstract: Tungsten trioxide (WO3) thin films have considerable interest due to its wide variety of properties, and extensively studied for various applications such as chromogenic devices, switching mirrors, optoelectronic devices and gas sensors. In this view, our present investigations are aimed at electron beam evaporated thin films of WO3. The films were deposited at an oxygen partial pressure of 2x10-4 mbar and at different substrate temperatures ranging from room temperature (RT) to 4500C. The films were annealed at 4000C about 2 hours and the properties were studied systematically. The X-ray Diffraction studies show the diffraction peak of (320) at 2θ = 44.070 which indicate the Orthorhombic phase of WO3 and also the other peaks represent the hexagonal phase of WO3. Due to annealing of the films, the monoclinic phase is also observed. The surface morphology of WO3 thin films was investigated by using Atomic Force Microscopy and Scanning Electron Microscopy, which supports the above data. The Energy Dispersive X-ray (EDX) compositional analysis confirmed the presence of W and O. The optical properties were studied by UV-VIS Spectrophotometry and hence the bandgap values are calculated.
Keywords: Tungsten trioxide thin films; annealed; structural; morphological; optical and compositional.
ALTERNATING CURRENT CONDUCTION STUDIES OF HYBRID NANOCOMPOSITE AT ROOM TEMPERATURE
by T. Chandrasekhar, Y.T. Ravi Kiran, C.H. V. V. Ramana, D.K. Mishra
Abstract: Polyaniline (PANI) and Polyaniline-Yttrium oxide (PANI-Y2O3) hybrid nanocomposite were synthesized separately by simple chemical polymerisation method and then they were structurally characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) techniques. The alternate current (AC) conduction parameters of PANI and the composite were comparatively studied in the frequency range 100Hz-1MHz at room temperature. The AC conduction results were interpreted as power law of frequency and the frequency exponent s and was found to lie in the range 0
Keywords: Polyaniline; Yttrium oxide; Polymer composites; AC conductivity; Correlated barrier hopping;.
Adsorption of Ni(II) ions from waste water by -MnO2-MCM-41: Isotherm, kinetics and thermodynamics
by Suresh Kumar Dash
Abstract: δ-MnO2 modified MCM-41 adsorbent was prepared by loading different amounts of δ-MnO2 (5, 10, 15 and 20 weight %) onto MCM-41 by direct-synthesis or in situ method. The synthesized materials were characterized by UV-vis diffused reflectance spectra, Fourier Transform Infrared spectra and BET surface area. The adsorbent (δ-MnO2-MCM-41) showed very high efficiency and sensitivity for removing Ni(II). By varying different parameters like initial Ni(II) concentration, pH of solution and temperature, it was concluded that highest adsorption took place for (5) δ-MnO2-MCM-41 at 323 K, and at a pH 3.0. The equilibrium isotherms fitted well to Langmuir and Freundlich models explaining modest adsorbate-adsorbent interactions. From kinetic studies the adsorption was found to follow the pseudo-second-order kinetics. The thermodynamic studies indicated endothermic nature with chemisorption mode.
Keywords: δ-MnO2-MCM-41; adsorption of Ni(II); Equilibrium isotherms; kinetic and thermodynamic studies.
Development of Defects in Nanocrystalline Zirconia: Studied through Photoluminescence Spectroscopy
by Shreenu Pattanaik, Sushanta Kamilla, Dilip Mishra
Abstract: Zirconium dioxide (zirconia) nanoparticle with monoclinic structure is successfully synthesized by chemical route i.e. pyrophoric method from aqueous solution of ZrOCl2.8H2O and triethanol amine. The structural and optical properties of the annealed samples have been investigated by using X-ray diffractometer, photoluminescence spectroscopy and UV-visible spectrometer. It is observed that the variations of annealing temperature from 650
Keywords: Zirconia; X-ray diffraction; Photoluminescence; Defects.
Preparation and Characterization of graphene Oxide Nanofluid and its Electrical conductivity
by Md. Zaved Hossain Khan, M. Abu Naser Shatez, K.Y. N. Ritee
Abstract: Recently, two dimensional honeycomb lattice structural graphene grants unique properties that are currently being pursued for conductive composites, advanced electronics, membranes etc. In this work, we report the preparation of graphene oxides (GO) nanofluids by dispersion of GO nanosheets in base fluid. Firstly, GO sheets were synthesized in controlled size using improved Hummer method by simply oxidation and facile exfoliation procedure. As prepared samples are characterized by UV-vis spectrometer, Fourier transform infrared spectroscopy (FTIR) spectrometer, scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). The XRD pattern revels that GO were form in nanoscale with crystalline structure. SEM image confirmed that GO were form in ultra small sheet state with smooth surface. UV-vis absorption spectrum reveals that GO nanosheets disperse well in the base fluid. FTIR result reveals the presence of functional group in the lattice which helps the graphene sheets to interact with water molecules and good dispersion. In terminology of electrical conductivity, the result suggests that the samples with 0.1% volume of GO had the highest conductivity with the value of 5310
Keywords: Graphene oxide; nonofluids; electrical conductivity; crystalline structure; nanosheets.
Assessing the potential of mesoporous MCM-41 nanoparticles for treatment of phenolic wastewater
by Dhananjay Naidu, Namita Panigrahi, Jyoti Mishra, Naresh Sahoo
Abstract: In the present study MCM-41 nano-particle was synthesized, characterized and applied for treatment of phenolic wastewater. In order to enhance the phenol adsorption efficiency adsorption parameters, such as pH, MCM-41 dosage and initial phenol concentration was optimized by employing statistical design of experiments using central composite design and response surface methodology. Result revealed that pH and adsorbent dose were found to have significant influence on phenol adsorption on to MCM-41. Further, among these significant factors adsorbent dose showed a large positive effect on the phenol removal. On the other hand, while pH showed strong negative interaction effect on phenol removal from synthetic wastewater. Further, it was observed that interaction between pH and phenol dose had significant effects on phenol removal from the synthetic wastewater. It was found that more than 99% phenol adsorption along with 96% of toxicity removal was achieved at an optimum combination of pH 5.2, phenol 132 mgl-1 and 2.6 gl-1 of MCM-41.
Keywords: Adsorption; MCM-41; Phenol; Response surface methodology; Interaction effect; Optimization.
Structural, optical and dielectric study of Cu doped ZnO nanoparticles synthesized by High Energy Ball Milling
by Bikram K. Das, Tanushree Das, Kajal Parashar, S.K.S. Parashar
Abstract: Cu doped ZnO nanoparticles abbreviated as Zn1-xCuxO (x=0, 0.01and 0.03) were synthesized by High Energy Ball Milling (HEBM) technique. The structural, morphological, optical and dielectric properties of the synthesized nanoparticles were carried out by XRD, FTIR, UV-Vis and impedance analyzer respectively. The incorporation of the dopant Cu into ZnO hexagonal wurtzite structure has been verified by X-ray diffraction (XRD). The effect of Cu doping on the structural bonding of ZnO has been verified by Fourier Transformation Infrared spectra (FTIR).The XRD spectra show that all the synthesized nanoparticles are single phase, hexagonal wurtzite structure and belong to the space group of p63mc. Compare to pure ZnO (18nm) the crystallite size of Cu doped ZnO (15nm) is smaller and peak broadening exists in the system. A similar feature of FTIR spectra has been observed for all samples, which supports the hexagonal wurtzite structure of ZnO even after Cu doping. The band gap (Eg) of ZnO decreases with Cu doping which can be attributed to sp-d exchange interaction between the ZnO band electrons and localized d electrons of Cu2+ ions. The dielectric constant of ZnO decreases with Cu doping.
Keywords: Ball Milling; XRD; FTIR; UV-Vis; Dielectric Constant.
Size controlled nanocrystalline TiO2 supported on mesostructured SBA-15 for better photocatalytic performance
by DIPTI R. SAHU, Sheng-Chang Wang, L.Y. Hong, Jow-Lay Huang
Abstract: Nanocrystalline TiO2 was prepared using sol gel hydrolysis and silica SBA-15 using organic solvent method. The synthesized SBA-15 served as the TiO2 support to reduce the TiO2 grain size and well-dispersed TiO2 for enhancement of photocatalytic activity. The synthesized titania/silica composites were characterized by X-ray diffraction, FTIR, TEM, UV-Visible spectroscopy, etc. TEM micrographs showed that the organic solute template method could prepare the titania-silica composite, and successfully embedded titania in SBA-15 channel. The mesoporous structure restrained the titania grain size within 5-7 nm which caused blue shift identified by UV-Vis spectra. The photo catalytic test of this material has been studied using methylene blue which shows improved performance than TiO2. Titania loading on the silica matrix decreases the surface area of the support and there is systematic decrease in their pore volume values, as titania content increases.
Keywords: Mesoporous; Titania; SBA-15; Nanoparticle; pore size.
Effect of Gamma Irradiation on Electrical and Magnetic Properties of Bismuth Doped Cobalt Ferrite Nanoparticles
by KRUTIKA ROUTRAY, DIRTHA SANYAL, Pratip Kumar Mukhopadhyay, DHRUBANANDA BEHERA
Abstract: Bismuth doped Cobalt ferrite nanoparticles has been prepared by sol-gel auto combustion method. An attempt has been made to study the electrical and magnetic transport properties of CoBixFe2-xO4 nanoparticles. The phase identification and morphological studies have been carried out by X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM). Obtained results confirm the presence of single phase spinal structure having space group Fd3m. In addition, FESEM micrographs reveal presence of spherical grains having diameters ranging from 20-130 nm. Further, dielectric studies of the prepared nanoparticles have been performed which suggests different types of conduction mechanism of the charge carriers. Results demonstrates the presence of dielectric relaxation, which is found to be of non-Debye type. Apart from these, Mossbauer study is conducted to observe the distribution of the cobalt and bismuth in the spinel ferrite. Moreover, in this study, effect of gamma irradiation on structural, dielectric and Mossbauer properties for various concentration of Bi have been discussed in detail.
Keywords: Nanoparticles; sol-gel auto combustion; X-ray diffraction (XRD); dielectric; Mossbauer spectra.
Performance Analysis of ZnO based Ultrasonic MEMS Transducer used for Blind Person Navigation
by Hara Prasada Tripathy, Priyabrata Pattanaik, Sashanta Kumar Kamilla
Abstract: Navigation is not an easy task especially without using eye. Creatures like bats and dolphins are navigated by creating ultrasonic wave. The sensory organs help them to create and sense the path without visualizing it. This paper imitates these creatures to propose an ultrasonic based MEMS transducer for blind person navigation. MEMS based acoustic transducers commonly employ the piezoelectric material. This model has been designed by using non-toxic and low cost compound like zinc oxide (ZnO) using COMSOL multiphysics. 2D axis-symmetrical model geometry is designed to imitate like sensory organ to sense the obstacle present 2 meters away from it. An optimized voltage of 5 volt and frequency of 20.103 KHz is applied to the proposed model to create ultrasonic wave. Further, the wave propagation in the air medium is analyzed by using 3D partial differential equation. The pressure waves are studied during transmitting and receiving time. The rebounded wave from the obstacle to the transducer is converted to 30.2mV by the proposed model. The von-misses stress is carried out to study the pressure on transducer surface.
Keywords: Navigation; Ultrasonic Wave; MEMS Transducer; Zinc Oxide (ZnO); COMSOL multiphysics; Von-misses Stress.
Comparison of magnetization and transport properties of processed La0.67Ca0.33MnO3 manganites for technological application
by DIPTI R. SAHU, D.K. Mishra
Abstract: A lot of efforts are being made to look for suitable types of colossal magnetoresistance (CMR) materials with specific composition for technological applications. We have synthesized and performed the magnetization and transport studies on La0.67Ca0.33Mn03 CMR polycrystalline materials prepared using melt and sintering technique. It is observed that the magnetoresistance is enhanced in partially melted sample with increase in insulator-to-metal transition temperature enabling its possible applications at room temperature. This indicates the high degree of spin polarization of the conduction electrons in partially melted sample. It has been observed that grain boundaries disrupt the local magnetic order and alter the electrical conduction of polarized electrons whereas the magnetization behaviour is not significantly affected except the magnitude of the magnetization. This suggests that the magnetic spin alignment in the weak link region of the sintered sample increases the absolute magnetization. The melt processed method is the ideal method to achieve superior magnetic and transport properties for possible major technological application of colossal magnetoreistive devices.
Keywords: CMR; Magnetization; Magnetoresistance; Transport.
Synthesis of Magnesium Oxide Nanopowder via Plasma Processing route
by Sanghamitra Dash, Rakesh K. Sahoo, Saroj K. Singh, Dinesh Singh Chauhan
Abstract: We describe a less time consuming and scalable thermal plasma process for the synthesis of magnesium oxide (MgO) nanoparticles. In this process, argon is used as the plasmagen gas to form argon plasma. In presence of argon plasma magnesite powder was decomposed to form nano magnesia within 10 minutes. This as-synthesized magnesia has been analysed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectrum (FT-IR) for phase, morphology and presence of surface functional groups, respectively. The phase and average crystallite size of the as-synthesized powder was determined from XRD pattern. Further, Raman spectroscopy was used to observe the phase and phase purity. Finally, the spherical shape of the as-formed magnesia powder was observed using TEM.
Keywords: Magnesium oxide; thermal plasma; structure; morphology; spherical particle.
Preparation and characterization of smart polymer-metal nanocomposite: Optical and morphological study
by Binay Bhushan
Abstract: The paper reports a novel polymer-metal nanocomposite. The composite structure is in the form of annular polydiacetylene (PDA) nanovesicles surrounded by silver nanoparticles both on the outer as well as inner surfaces of the vesicle structure. The synthesis route has been described in detail and the rationale behind the synthesis procedure has been discussed. The composite structure has been characterized by UV-Vis spectroscopy while its morphology has been studied based on the result of transmission electron microscopy and electron diffraction pattern. Our synthesis procedure does not require any catalyst, contrary to what has been reported in the literature. The coupling between electrons of PDA and free electrons of silver nanoparticles in the composite system is particularly useful for nonlinear optical applications. We have also outlined some of the strategies that could be explored in future so that such composite system could be a better potential candidate for photonic devices.
Keywords: Polydiacetylene; Silver; Nanoparticles; Nanocomposite.
Effect of Annealing Temperature On Super capacitive Behavior Of Hydrothermally Synthesized ZnO Nano-platelets
by Arya Das, Rakesh K. Sahoo, Saroj K. Singh
Abstract: ZnO nano-platelets have been prepared using a high pressure reactor via hydrothermal route and calcinated at different temperatures. The structure and morphology of the grown Zinc oxide (ZnO) nano-platelets (NP) at different temperatures has thus been reported. Raman spectroscopy and X-ray diffraction (XRD) confirmed ZnO formation. The nano-platelets morphology was confirmed by Scanning Electron Microscopy (SEM). The change in morphology and its adverse effect on the capacitive behavior of the as-synthesized nano-platelets with change in calcination temperature has also been discussed. The potential of these nano-platelets for possible applications in energy storing devices has been established.
Keywords: ZnO Nano-platelets; Cyclic voltammetry; Supercapacitor.
Aesthetic Improvement Of Transparent Natural Quartz By Heat Treatment At Different Temperature
by Rakesh K. Sahoo, Saroj K. Singh, B.K. Mishra, Biswa Bhusan Dhal
Abstract: Attempt has been made by us to improve the aesthetic value of natural gem variety transparent quartz from of Odisha through heat treatment with cobalt oxide powder and the results are reported. Natural occurring quartz stones were surface cleaned and heat treated at different temperatures with cobalt oxide to alter the color and clarity. A series of experiments by adding cobalt oxide additive at different temperature were carried out to study the alteration of aesthetic values. The change in color and chemistry on the surface of the treated stones with respect to the untreated one were compared. Moreover, in this work improvement in aesthetic value of the quartz stone and its consequent change in surface chemical and physical characteristics before and after heat treatment at different temperatures have been compared and described.
Keywords: Quartz; heat-treatment; Cobalt oxide; surface analysis; Odisha.
Special Issue on: ICONAN 2016 Recent Advances in Nanomedicine Delivery, Diagnosis and Therapy
Collagen/Chitosan Hybrid 3D-Scaffolds as Potential Biomaterials for Tissue Engineering
by Hilary Urena-Saborio, Emilia Alfaro-Viquez, Daniel Esquivel-Alvarado, Marianelly Esquivel, Sergio Madrigal-Carballo
Abstract: Chitosan (CHT) has been reported to be biocompatible, bio-absorbable and particularly, is considered a good wound-healing accelerator. On the other hand, collagen (CGN) is one of the most widely used matrix biomaterial in tissue engineering. Highly porous CGN single 3D-scaffolds have been used to support in vitro growth of many types of tissues. We fabricated hybrid 3D-scaffold biomaterials by mixing CHT from native shrimp waste streams and CGN from tilapia aquaculture waste by-products, applying previously developed methodologies involving solvent casting and freeze-drying. CGN/CHT hybrid 3D-scaffolds were characterized according to its water uptake capacity, mechanical properties, thermal behavior (TGA), and morphology (SEM). Hybrid 3D-scaffolds showed improved stability, greater porosity, increased thermal stability, and mechanical properties, as well higher biodegradation as compared to single 3D-scaffolds. Cell culture incubation with adipose tissue-derived stem cell (ADSC) and SEM imaging showed that CGN/CHT hybrid 3D-scaffolds allowed ADSC adhering, spreading, and growing in vitro.
Keywords: Collagen; chitosan; scaffolds; tissue engineering.