Advanced Materials Research Vol. 1169

Abstract: The composite materials of ST & BT ceramics were prepared by using solid state reaction method. The dielectric parameters of ST & BT ceramics of particle size 125 micron like dielectric constant (ε'), loss (ε"), quality factor (QxF), relaxation time (τ) and conductivity (σ) has been studied at different temperatures i.e. -10°C, +10°C, +30°C and +50°C. the values of dielectric parameters are found greeter of ST then BT but the relaxation time of ST is found smaller than BT.

Abstract: Photopolymerisation of 2-Hydroxyethyl methacrylate (HEMA) through the use of N,N-Diethyldithiocarbamato-(1,2)-propanediol (DCPD) was studied. The photoinitiator DCPD was synthesized from sodium N,N-Diethyldithiocarbamate (NaSR) and 3-chloro-1,2-propanediol. For the photochemical decomposition of the C – S bond, UV light at 254 nm is used. The role of the monomer concentration, reaction time and DCPD to HEMA mol ratio on the conversion of HEMA to PHEMA were studied in this paper. It was found that percentage conversion of HEMA increased both with the rise in concentration of monomer and reaction time. Further, living radical nature of the poly2-Hydroxyethyl methacrylate (PHEMA) was ascertained by the photo block copolymerization of methyl methacrylate (MMA) with PHEMA to form PHEMA-b-PMMA. The PHEMA and PHEMA-b-PMMA were characterized by FTIR, ¹H-NMR, Thermogravimetry.

Abstract: Wet chemical methods in particular sol-gel auto combustion method play a vital role in governing the size and the shape of the particles. In the present communication, nickel ferrite nanoparticles were prepared by sol-gel auto combustion technique using citric acid as a fuel. The metal nitrate to fuel ratio was chosen as 1:3 using propellant chemistry approach. The nanopowder of the nickel ferrite was prepared at various pH viz. 2, 5, 7 and 9. The obtained nanopowder was annealed at 600°C for 4 h and used for further characterizations. All the samples were structurally characterized by X-ray diffraction and infrared spectroscopy technique. The room temperature XRD pattern reveals the formation of single-phase cubic spinel structure. The lattice constant calculated from XRD data shows dependence of pH values. The Fourier transform infrared spectra show two absorption bands in all the four samples near 400 cm^-1 and 600 cm^-1. However, a slight variation in the absorption band is observed for different pH.

Abstract: Polymers with metal oxide materials constitute a new class of polymer composite materials, that integrates materials science and technology. Chemical oxidation of aniline is carried out for PANI (PANI) and in-situ polymerization for PANI/AgO nanocomposite materials. Characterization tools such as XRD and SEM were used. The AC conductivity and dielectric behavior are investigated in the frequency range 100 to 2MHz at room temperature. It is observed that, the AgO nanoparticles in the PANI matrix have a greater influence on the AC conductivity and dielectrics.

Abstract: The spinel ferrite nanoparticles are of great importance to the scientist and technologist. Lithium ferrite is one of the best spinel ferrite used in many technological applications. In the present communication, we report the synthesis of lithium ferrite (Li_0.5Fe_2.5O₄) using sol-gel autocombustion method. Dextrose was used as a chelating agent in the synthesis and the metal nitrates to dextrose ratio was taken as 1:4. The as prepared powder of lithium ferrite was annealed at 550 °C for 4h. A non destructive X-ray diffraction technique was employed to study the phase evolution and crystal structure. The X-ray diffraction pattern was analysed and result suggest that the prepared nanoparticles of lithium ferrite possess single phase cubic structure. No extra peak other than the cubic phase was seen in the XRD pattern. The crystallite size was estimated using Debye Scherrer formula taking into consideration the most intense peak (311) present in the XRD pattern. The full width at half maxima (FWHM) was obtained through (311) plane. The crystallite size was obtained to be 23 nm, indicating the nanocrystalline nature of the prepared samples. The unit cell parameters that is lattice constant obtain from XRD data found to be in good agreement with the reported value. The other structural parameters like hopping length, tetrahedral radius, octahedral radius etc were determined their dependence with lattice constant is discussed in this work.

Abstract: The aim of the present research work was to prepare NiFe₂O₄ nanoparticles using standard wet chemical method namely sol-gel auto-combustion with a view to study them in heat transfer application. The prepared nanoparticles of NiFe₂O₄ were then applied to prepare nanofluid with deionised water as a base fluid. The characterization of the prepared NiFe₂O₄ nanopowder is done by X-ray diffractometer (XRD) technique. The XRD pattern was recorded at room temperature. The analysis of XRD pattern was carried by standard software suggests that prepared nickel ferrite nanopowder possess single phase cubic spinel structure. The lattice constant was obtained by using XRD data reasonably agree with the reported values. The mean size of the particle was estimated through XRD pattern, in which the most intense peak (311) was considered to obtain full width at half maxima (FWHM). The Scherrer formula was used to obtain average crystallite size which was found to be 33 nm. The surface morphology of the prepared NiFe₂O₄nanopowder was studied by means of scanning electron microscopy (SEM) technique. The average grain size determined by linear intercept method was found to be of the order of 40 nm. The SEM image shows formation of spherical grains with some agglomeration. The prepared nanofluid of nickel ferrite was used to estimate thermal conductivity. It was found that, the thermal conductivity of NiFe₂O₄nanofluid was increased compared to deionised water.

Abstract: Thin film of cobalt ferrite has been deposited on glass substrate by a chemical spray pyrolysis technique using methanol solutions at 400^◦C substrate temperature. The uniformly deposited thin film were annealed at 500 ^◦C and studied their structural, infrared and optical properties using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectroscopy (UV-Vis), respectively. The X-ray diffraction patterns revealed single phase cubic spinel structure with space group Fd-3m. The fundamental absorption bands related to octahedral and tetrahedral sites were confirmed by Fourier-transform infrared spectroscopy (FTIR) spectrum.The formation of cubic spinel crystal structure of the CoFe₂O₄ thin filmwere confirmed from exhibited strong absorption peaks around 530.21 and 451.48 cm⁻¹ by FT-IR spectra.The optical properties of the deposited thin film were studied by an absorbance spectrum found at 315 nm. The value of energy bandgap (2.4 eV) wasinvestigated by Tauc plot.The obtained results indicate the fabricated thin film is promising material for various applications.

Abstract: In the present work, we have designed a low-cost spin coater using the Arduino Uno board. The advantage of selecting Ardunio is, it has pulse width modulation (PWM) based pins. Depending on the width of the pulse, the output voltage changes which will intern changes the speed of the DC motor connected to the PWM pin. The thickness of deposited film using spin coater depends on RPM and duration of rotation. The rotation of the substrate during deposition has three stages a gradual increase in RPM, maintaining constant RPM over a while, and a gradual decrease in RPM. All these parameters can be controlled by an Arduino board. An Aluminum doped Zinc Oxide film was deposited on glass substrate using Arduino based spin coater. X-ray diffraction, UV – VIS spectroscopy, and FTIR methods were used as characterization techniques. Hexagonal crystal structure of deposited AZO layer was confirmed by XRD and optical band gap, transparency were calculated by UV-VIS spectroscopy.

Abstract: ED-XRF technique was used for quantification of elemental concentration in bark and leaves of Aegle marmelos L. is an anti-asthmatic herbal plant. 13 major and trace elements namely P, S, K, Cl, Mn, Ca, Cu, Fe, Zn, Rb, Sr, Br, and Se were determined, concentrations measured and compared between bark and leaves and with certified values of NIST 1515 apple leaves. The experimental data reveal that leaves of A. marmelos showed higher concentration of Mn, K, Zn, Se, Cl, Ca, Br and Rb whereas the bark showed higher concentration of P, S, Fe, Cu, and Sr. The major and trace elemental concentrations in both bark and leaves were found to be diverse. The significant findings of the current study are, the leaves of A. marmelos were considered more efficient traditional herbal medicine than bark, since they are found to be containing a rich amount of Mn, K, Zn, Se, Cu, and Fe. Therefore, the tribal people of Telangana are widely used by this plant to prevent asthma disease.