Editorial
Hisatoshi Kobayashi; Mikael Syväjärvi
Abstract
All of us are in different stages of our careers. Like materials, time is needed to develop the foundation of a career or technology platform. We will enter challenges, and sometimes very much energy is needed. In our research, we find our special place in a research arena. Like successful business approaches, ...
Read More
All of us are in different stages of our careers. Like materials, time is needed to develop the foundation of a career or technology platform. We will enter challenges, and sometimes very much energy is needed. In our research, we find our special place in a research arena. Like successful business approaches, we find niches where we have an advantageous edge. At such times, we can use our inspiration and learn from each other.
Research Article
Ankur Soam; Rajiv Dusane
Abstract
The development of micro-supercapacitor (µ-SC) based on silicon nanowires (SiNWs) has increased the demands ofcost-effective methods via low temperature processing routes for the fabrication of SiNWs which can enable the realization of µ-SC directly on a Si chip. In this work, SiNWs synthesized ...
Read More
The development of micro-supercapacitor (µ-SC) based on silicon nanowires (SiNWs) has increased the demands ofcost-effective methods via low temperature processing routes for the fabrication of SiNWs which can enable the realization of µ-SC directly on a Si chip. In this work, SiNWs synthesized by hot-wire chemical vapor processing (HWCVP) at low substrate temperature of 350 oC have been explored as the electrodes for the use in µ-SC. Electrochemical behavior was tested by using cyclic voltammetry (CV) and galvanostatic charging/discharging in an ionic electrolyte. TEM characterization reveals as-grown SiNWs have inner crystalline core (c-core) sheeted with an amorphous layer of silicon (a-Si) which has poor electrical conductivity and reduces the capacitance of SiNWs. Copyright © 2017 VBRI Press.
Research Article
Bikash Mandal; I. Basumallick; Susanta Ghosh
Abstract
Highly dispersed, porous and nano-sized FePO4 have been synthesized by a facile aqueous and alcoholic medium for their application as cathode in rechargeable lithium batteries. Various dispersing templates in association with suitable solvents are used to introduce porosity and dispersive nature among ...
Read More
Highly dispersed, porous and nano-sized FePO4 have been synthesized by a facile aqueous and alcoholic medium for their application as cathode in rechargeable lithium batteries. Various dispersing templates in association with suitable solvents are used to introduce porosity and dispersive nature among the particles and to reduce the size of the particles. Characterization with FTIR, powder XRD and SEM suggests the formation of less crystalline, pure FePO4 with high surface area and high porosity. Cyclic voltametry has been employed to test the intercalation behaviour of lithium ions and confirms the reversible nature of the material. The role of the dispersing template for the material growth and the electrochemical performances of the synthesized FePO4 as cathode in lithium battery have been discussed. It is found that poly(styrene-co-divinylbenzene) as the dispersing agent produces highly dispersed material with highest discharge capacity of 138 mAh.g-1. Copyright © 2017 VBRI Press.
Research Article
Yashvant Rao; Gajendra Kumar Inwati; Man Singh
Abstract
Cadmium sulphide nanocrystals (CdS NCs) of ≈ 7.0 nm have been synthesized and structurally characterized with X-Ray Diffraction (XRD), High Resolution Transmission Electron Microscope (HR-TEM) and topographical 3D image by Atomic Force Microscopy (AFM). The binding and kinetic energies of 5th electron ...
Read More
Cadmium sulphide nanocrystals (CdS NCs) of ≈ 7.0 nm have been synthesized and structurally characterized with X-Ray Diffraction (XRD), High Resolution Transmission Electron Microscope (HR-TEM) and topographical 3D image by Atomic Force Microscopy (AFM). The binding and kinetic energies of 5th electron of 3d orbital (inner 3d5/2) and 3rd (outer 3d3/2) of Cd were 405.93 and 412.67 eV as well as 1074 and 1080.76 eV respectively determined with XPS. The CdS at 298.15 K, when dispersed in water, methanol and ethanol with 100 µM each of rhodamine B (RB), sulphorhodamine B (SRB) and carboxyfluorescein (CF) the fluorescent dyes (FD) separately has enhanced UV-Vis absorbance by 45, 30 and 25% respectively in order of (RB-CdS) > (SRB-CdS) > (CF-CdS) within 200 to 320 nm as compared to without CdS. Probably the CdS has functionalized the functional groups of the dyes that could have induced the p-conjugated bonds to detain higher UV-Vis abs. especially one -COOH, four -CH2CH3, two -SO3, four -CH2CH3 and two –COOH, one >C= with one hydroxyl group respectively. Thus, the CdS-Dye-UV-Vis model could be proposed as new finding of our studies. Copyright © 2017 VBRI Press.
Research Article
Anandraj J; Girish M. Joshi; Mayank Pandey
Abstract
We have demonstrated the successful preparation of polyvinyl alcohol (PVA) composed CuBi2S3 polyionic (PI) composites. Polymer composites were sensitive to the external stimuli, the modified PVA moiety exhibits excellent electrical property as a function of temperature. The volume resistance measured ...
Read More
We have demonstrated the successful preparation of polyvinyl alcohol (PVA) composed CuBi2S3 polyionic (PI) composites. Polymer composites were sensitive to the external stimuli, the modified PVA moiety exhibits excellent electrical property as a function of temperature. The volume resistance measured by impedance analyzer (40 to 150oC) under broadband frequency (50Hz -1MHz). The negative temperature coefficient (NTC) was observed in the temperature range of 40 to 150oC. It offers the nonlinear resistivity, ρ = 105 (Ω-m) across pure PVA moiety. The influence of polycationic-ions crucial to obtain the gradual decrease of resistivity (ρ) up to 104 (Ω-m). The thermistor characteristics were disclosed as function of polyionic loading (wt %). Copyright © 2017 VBRI Press
Research Article
Panmei Gaijon; S. K. Shukla; Monika Datta
Abstract
Presently, polymer-clay composites (PCC) have shown promising advancements in different properties of polymers due to presence of layered silicate structure and also extend its multi fold advanced applications. In the present work, vermiculite (VT) was organically modified by cetylpyridinium chloride ...
Read More
Presently, polymer-clay composites (PCC) have shown promising advancements in different properties of polymers due to presence of layered silicate structure and also extend its multi fold advanced applications. In the present work, vermiculite (VT) was organically modified by cetylpyridinium chloride (CPC). Thus obtained organo vermiculite (OVT) was used to prepare its composite film with polystyrene (PS-OVMT) with varying amounts of OVT by the solution blending and casting method on a glass substrate. The prepared films were characterized by scanning electron microscope (SEM), x-ray diffraction (XRD), infrared (FT-IR) spectroscopy and thermal analytical (TG-DTA) techniques. X-ray diffraction pattern of the composite shows peaks of VT and PS along with decrease in the intensity of the PS peaks present between 2Ө = 12.5˚ to 24.5˚. Decreases in the intensity of peaks suggest dispersion of clay within the polymer matrix and lowering of crystallinity. The dispersion of clay and interaction with PS is also evident from the FTIR and microscopic data. Further, hardness test (shore-D), TG-DTA and flammability(UL-94) results of the composite indicate the improvement in hardness, thermal stability and inhibition in burning behaviour of the PS due to the presence of OVT in the PS matrix. Copyright © 2017 VBRI Press.
Research Article
Yana Bagbi; Ankur Sarswat; Sachchidanand Tiwari; Dinesh Mohan; Arvind Pandey; Pratima R. Solanki
Abstract
Zero-valent iron nanoparticles (NZVI) were synthesized using chemical reduction method. These were applied for lead removal from water. The structural, morphological, compositional and optical studies were studied out using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic ...
Read More
Zero-valent iron nanoparticles (NZVI) were synthesized using chemical reduction method. These were applied for lead removal from water. The structural, morphological, compositional and optical studies were studied out using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering, scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR). The NZVI optical energy band gap as calculated by UV absorption spectrum was 1.7 eV. The zeta potential was obtained as -32.0 mV. The biocompatibility test of NZVI was performed using MTT assay on MDCK-2 as model cell lines. Lead adsorption on NZVI was examined at different pHs, equilibrium time, temperature, and NZVI/Pb2+ concentrations. Almost 100% Pb2+ removal was achieved at NZVI dose: 0.4 g/L;Pb2+ concentration: 50 mg/L; equilibrium time: 15 min; pH 5-6; and temperature: 25°C. Pb2+ sorption kinetic data were fitted to pseudo-first and second-order kinetic equations. Pseudo-second-order kinetic equation best fitted the data. These studies clearly demonstrate NZVI as an efficient nano-adsorbent for Pb2+ removal from water. Copyright © 2017 VBRI Press
Research Article
Richa Sharma; N. C. Mehra; R. P. Tandon
Abstract
In the present work, the composite series (1-x) Ba0.94Ca0.06TiO3 - (x) Ni0.7Co0.1Zn0.2Fe2O4 (where x = 0.1, 0.2, 0.3 and 0.4 wt. fraction) was synthesized by solid state reaction method followed by conventional sintering. The structure and morphology of prepared samples were examined using X-ray diffractometer ...
Read More
In the present work, the composite series (1-x) Ba0.94Ca0.06TiO3 - (x) Ni0.7Co0.1Zn0.2Fe2O4 (where x = 0.1, 0.2, 0.3 and 0.4 wt. fraction) was synthesized by solid state reaction method followed by conventional sintering. The structure and morphology of prepared samples were examined using X-ray diffractometer (XRD) and scanning electron microscopy (SEM), respectively. In addition, dielectric constant (ε΄) and loss tangent (tan δ) of prepared samples were measured as a function of frequency and temperature. The room temperature values of dielectric constant (ε΄) of composite samples are found to decrease from 529.29 to 159.52 as ferrite content increased from x = 0.1 to x = 0.4 at 1 kHz frequency. Moreover, in the dielectric constant vs. temperature plots of the composite samples, ferroelectric to paraelectric phase transition of pure Ba0.94Ca0.06TiO3 is observed. Furthermore, ferroelectric and magnetic properties of the composite samples were studied at room temperature. With increasing addition of the ferrite content in the composites, the ferroelectric properties get weakened and the magnetic behavior of the composite samples improved. The maximum values of saturation magnetization ( ) and remanant magnetization ( ) are 22.52 emu/gm and 3.39 emu/gm, respectively, for composite sample containing 0.4 wt. fraction Ni0.7Co0.1Zn0.2Fe2O4. Copyright © 2017 VBRI Press.
Research Article
Eagambaram Murugan; Venkatesan Yogaraj
Abstract
Quaternary ammonium poly(amidoamine) (PAMAM) dendrimer stabilized gold nanoparticles (QPAMAM-AuNPs) were prepared and used for fabrication of new GC-QPAMAM-AuNPs electrode and this in turn was investigated for sensing of trace quantity of H2O2. Further, the QPAMAM-AuNPs were inspected for catalysis of ...
Read More
Quaternary ammonium poly(amidoamine) (PAMAM) dendrimer stabilized gold nanoparticles (QPAMAM-AuNPs) were prepared and used for fabrication of new GC-QPAMAM-AuNPs electrode and this in turn was investigated for sensing of trace quantity of H2O2. Further, the QPAMAM-AuNPs were inspected for catalysis of nitrobenzene. Initially, amine-terminated PAMAM dendrimer was neutralised by acetylation followed by quaternization reactions. This quaternized product was used as a template for stabilization of gold nanoparticles by conducting the reactions at room temperature and thus produced quaternized dendrimer stabilised gold nanoparticles labelled as QPAMAM-AuNPs. The synthesized QPAMAM-AuNPs were characterized by UV-Vis, FTIR, 1H NMR, MALDI-TOF and TEM analyses. This QPAMAM-AuNPs was coated on newly produced glassy carbon modified electrode without any binding agent, particularly any enzyme to produced GC-QPAMAM-AuNPs electrode. This newly fabricated electrode in turn were employed for detection and sensing of trace quantity of H2O2 and it is observed that the electrode has an ability to detect the H2O2 ranging from [100 µM] to [5 mM] in neutral pH. Similarly, it is also proved that QPAMAM-AuNPs has effectively reduced the nitrobenzene and the observed pseudo-first order rate constant was 25.25 ×10-3s-1. It is established that the stabilized nanoparticles are water-soluble and stable for three months. Copyright © 2017 VBRI Press.
Research Article
N. Sivasankarareddy; R. Viswanatha; B. Sujatha; C. Narayanareddy
Abstract
Correlation between mechanical properties and MAS NMR spectroscopic revelations have been carried out on the glass system, xZnO – 50 B2O3 – (50 – x) V2O5 where 15 ≤ x ≤ 40 is prepared by a novel microwave heating method. Elastic moduli were computed from ultrasound velocities ...
Read More
Correlation between mechanical properties and MAS NMR spectroscopic revelations have been carried out on the glass system, xZnO – 50 B2O3 – (50 – x) V2O5 where 15 ≤ x ≤ 40 is prepared by a novel microwave heating method. Elastic moduli were computed from ultrasound velocities measured by a pulse echo superposition method. Both ultrasound velocities and elastic properties increase monotonically as a function of ZnO content. The variations observed in the mechanical properties were explained in view of modifications occur in the network structure consisting of borovanadate units. The bulk and shear moduli increase due to the presence of four coordinated borons along with diborovanadate units, which increases the dimensionality and connectivity of the glass network. Surprisingly, the process of the reconversion of four coordinated borons into three coordinated borons beyond 33.3mol% of modifier concentration is not initiated in these glasses, which is essentially due to the formation of [B2V2O9]2- units similar to the [B4O7]2-units. This is well supported by the monotonic increase in N4 - values even above the 33.3 mol%of modifier content. Materials with enhanced elastic properties find application in cathode materials. Copyright © 2017 VBRI Press.
Research Article
Shuhaib Mushtaq; M.F Wani
Abstract
In the present study, micro hardness values of Iron-Copper based alloys with different compositions have been obtained by using Vickers indenter. The samples Fe-5Cu-1Sn-7.5BN (wt. %), Fe-5Cu-1.5Sn-5BN (wt. %) and Fe-5Cu-2.5Sn-2.5BN(wt. %) were prepared using Powder metallurgy technique. The elemental ...
Read More
In the present study, micro hardness values of Iron-Copper based alloys with different compositions have been obtained by using Vickers indenter. The samples Fe-5Cu-1Sn-7.5BN (wt. %), Fe-5Cu-1.5Sn-5BN (wt. %) and Fe-5Cu-2.5Sn-2.5BN(wt. %) were prepared using Powder metallurgy technique. The elemental powder mixture was mixed for 2 hours, and compacted at a pressure of 500Mpa, and then was sintered in dry hydrogen atmosphere at a temperature of 9000C for 50 minutes time. Vickers hardness values were obtained under the loads of 0.01 kg to 0.3 kg. The material with 2.5 wt. % of Sn exhibited the highest value of the hardness. The material with higher hardness shows better mechanical and tribological properties and can be used for various applications such as gears, bearings, connecting rods cams etc. Copyright © 2017 VBRI Press.
Research Article
Prahlad K. Baruah; Ashwini K. Sharma; Alika Khare
Abstract
In this paper, the effect of incident laser energy on the localized surface plasmon resonance (LSPR) and size of copper (Cu) nanoparticles (NPs) synthesized via pulsed laser ablation of copper in distilled water (DW) is reported. The absorption spectra show plasmon peak in the visible spectral region. ...
Read More
In this paper, the effect of incident laser energy on the localized surface plasmon resonance (LSPR) and size of copper (Cu) nanoparticles (NPs) synthesized via pulsed laser ablation of copper in distilled water (DW) is reported. The absorption spectra show plasmon peak in the visible spectral region. The increase in the laser energy from 30 mJ to 70 mJ of the second harmonic of a Q-switched Nd:YAG laser induces a blue shift in the plasmon peak from 627 nm to 617 nm along with its broadening from 180 nm to 242 nm, respectively. These observations have been explained on the basis of the effect of the small size of the NPs formed. The Transmission electron microscope (TEM) substantiates these results as it shows the decrease in the average particle size of the NPs from ~20 nm to ~7 nm with the increase in the incident laser energy from30 mJ to 70 mJ, respectively. By merely increasing the laser energy, a size-dependent LSPR has been achieved and this can be used as an effective way to control the size of Cu NPs and hence LSPR. Copyright © 2017 VBRI Press.
Research Article
Deepak M. Kapse; Pradnya Parab; Sangita Bose; H. Muthurajan
Abstract
Due to the toxicity of lead, there is an urgent necessity to develop lead-free alternatives to replace the currently dominant lead-based piezoelectric such as Pb(Zr,Ti)O3 (PZT). Na0.5K0.5NbO3 based piezoelectric nanomaterial are promising because of their relatively high Curie temperatures as well as ...
Read More
Due to the toxicity of lead, there is an urgent necessity to develop lead-free alternatives to replace the currently dominant lead-based piezoelectric such as Pb(Zr,Ti)O3 (PZT). Na0.5K0.5NbO3 based piezoelectric nanomaterial are promising because of their relatively high Curie temperatures as well as good piezoelectric coefficients among the non-lead piezoelectrics. We have successfully synthesized 3-dimensional perovskite nanocubes of functional ternary transition-metal oxide of sodium potassium niobate Na0.5K0.5NbO3 by using novel synthesis method. We have carried out resistance and impedance spectroscopy studies at low temperature using two probe technique. For this electrical measurement, we have used CCR system. There has been much interest in the texturing of electro ceramics, due to the possibility of achieving enhanced electrical properties. A major purpose for this electrical characterization study is to examine how Na0.5K0.5NbO3 (NKN) pellet behaves under low temperature. Copyright © 2017 VBRI Press.
Research Article
Sayantan Pathak; Niladri Biswas; Barun Jana; Tanmay K Ghorai
Abstract
The synthesis and crystal structure of Cu2(C6H5COO)4(C6H5COOH)2 (1) is herein reported. However, our intention was to incorporate Pb into the present system and make a new high nuclearity heteronuclear Cu-Pb cluster with magnetic or antibacterial properties. For its synthesis, first Cu (NO3)2.3H2O (2mmol) ...
Read More
The synthesis and crystal structure of Cu2(C6H5COO)4(C6H5COOH)2 (1) is herein reported. However, our intention was to incorporate Pb into the present system and make a new high nuclearity heteronuclear Cu-Pb cluster with magnetic or antibacterial properties. For its synthesis, first Cu (NO3)2.3H2O (2mmol) and PhCOOH (10mmol) was dissolved in a mixed solvent MeCN/EtOH (10/10, v/v); separately Pb(NO3)2 (1mmol) was dissolved in EtOH/H2O (20/5, v/v) and added drop-wise to the previous mixture. The mixture was stirred vigorously for half an hour with step-wise addition of NaN3 (2mmol). The heterogenous reaction mixture was filtered and the deep greenish filtrate was stored at ambient condition. In four weeks, green single crystals were generated at the bottom of the flask. Single crystal X-ray measurement shows the formation of the title compound, where Cu atoms are in +2 oxidation state that is further confirmed by BVS calculation. The Cu-Cu distance in the molecular structure is found to be 2.608 (2) Å, which indicates a Cu-Cu bond in the molecule. Each Cu atom is bonded to four oxygen atoms of two benzoate ligands and one oxygen atom of a benzoic acid molecule. The octahedral geometry of the copper(II) atoms are fulfilled by an additional copper-copper bond. The most interesting in complex 1 is both intra and intermolecular hydrogen and C-H-C bonding present in the system. The length of nano molecular size of the Cu2 cluster is found to be 1.55nm. The antibacterial study of complex 1 has been checked and it has no such high antibacterial activity. Copyright © 2017 VBRI Press.
Research Article
Ram J. Sengwa; Shobhna Choudhary
Abstract
Dielectric dispersion and relaxation behaviour of aqueous solution grown polymeric nanocomposite films consisting of poly(vinyl alcohol) (PVA) and alumina (Al2O3) (PVA–x wt% Al2O3 (x = 0, 1, 3 and 5)) have been studied in the frequency range from 20 Hz to 1 MHz by employing dielectric relaxation ...
Read More
Dielectric dispersion and relaxation behaviour of aqueous solution grown polymeric nanocomposite films consisting of poly(vinyl alcohol) (PVA) and alumina (Al2O3) (PVA–x wt% Al2O3 (x = 0, 1, 3 and 5)) have been studied in the frequency range from 20 Hz to 1 MHz by employing dielectric relaxation spectroscopy (DRS). It is found that at constant frequency, the real part of complex permittivity increases nonlinearly with the increase of Al2O3 nanoparticles concentrations in the PVA matrix, whereas it decreases with increase of frequency at constant concentration of Al2O3. The temperature dependent investigation on PVA–3 wt% Al2O3 film reveals that the dielectric properties increase with the increase of temperature confirming its thermally activated dielectric behaviour. The ac electrical conductivity of the nanocomposites increases and the impedance values decreases with the increase of frequency which are moderately affected by Al2O3 concentrations(x = 0 to 5 wt%) and temperatures (30 to 60 °C). The dc conductivity and relaxation time of PVA chain segmental motion of the nanocomposites obey the Arrhenius behaviour. The X-ray diffraction (XRD) study reveals that the crystallite size and amorphous phase of PVA increase with the increase of Al2O3 concentration in the PVA–Al2O3 nanocomposites. Results of this study confirm the suitability of PVA–Al2O3 nanocomposite materials as tunable nanodielectric for their use as insulator and substrate in the fabrication of microelectronic devices operated at audio and radio frequencies. Copyright © 2017 VBRI Press.
