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Zn1-XPbXS (x = 0–0.4 in steps of 0.1) ternary semiconductor samples have been prepared by co-precipitation method. The structural, optical and electrical studies have been carried out on all these samples to understand the influence of Lead on these properties. X-ray diffractograms showed that all Zn1-XPbXS samples have polycrystalline nature with Hexagonal phase. The room temperature optical absorption studies revealed that energy gap decreases with increase of Pb in Zn1-XPbXS compounds. The temperature-dependent conductivity, measured in the range 300–4 K, led to understand that the conduction mechanisms at 60 K and 30 K are different. The activation energies evaluated at low (300–60 K) and very low temperature (60–30 K) regions are 38.03–32.58 meV and17.99–13.56 meV respectively. Activation energy and conductivity of Zn1-XPbXS samples increase with the increase of Pb. The samples exhibited low freezing temperature points indicating the possibility of their use in low temperature device applications.

Pb1-xZnxS (x = 0 to 0.4 in steps of 0.1) ternary semiconductor material shave been prepared by co-precipitation method. The structural and electrical studies have been carried out to understand the influence of Zinc on activation energy. X-ray diffractograms showed that the Pb1-xZnxS compounds are polycrystalline in nature with cubic phase. The temperature-dependent conductivity measured in the range 300–4 K showed a change in the conduction mechanism at 62 K and 31 K. The activation energies evaluated at low and very low temperature regions. Activation energy increases and conductivity decreases with the increase of Zn in Pb1-xZnxS compounds. The samples are exhibiting low freezing temperature points indicating their capability to use in low temperature applications.

The present study involves synthesis of bulk polycrystalline samples of Cd0.8−xPbxZn0.2S through low cost controlled Co-precipitation method. The synthesized compounds were characterized with respect to their crystal structure, particle size and photoluminescence properties using X-ray diffraction (XRD), and PL spectroscopy respectively. XRD results revealed that both cubic and Hexagonal phases are present in the compounds. PL studies indicated the photosensitive character of the compounds. Blue shift in the peak position in PL spectra with increase in concentration of Pb indicates the increase in the energy gap. PL spectra confirmed the formation of defect levels in the forbidden energy gap and the transition is thought to occur from donor levels to acceptor levels.

Zn 1-x Cd x O (x=0, 0.04, 0.06, 0.08) ternary alloys were successfully synthesized by Sol–gel method. The prepared powders were sintered at 800°C for 4hrs. The compositional, structural and optical studies were investigated by SEM equipped with EDS, XRD and UV-Visible Spectroscopy. XRD results were compared with JCPDS data and confirmed the formation of Cd doped ZnO nanoparticles with polycrystalline single phase hexagonal wurtzite structure. The crystallite size was found to decrease from 21 to 17 nm with increase in the concentration of Cd. EDS analysis revealed the existence of Cd content in ternary alloys. From Ultraviolet-visible spectral studies optical band gap vary from 3.21 eV to 3.12 eV with Cd concentration. © 2016 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of International conference on materials research and applications-2016.

Polycrystalline CuxZn1−xS (0 ≤ x ≤ 0.1) semiconductor compound powders were prepared by controlled co-precipitation method in an alkaline medium using thiourea as a sulfide source. X-ray diffractograms of CuxZn1−xS powders showed that they possess polycrystalline nature with Hexagonal crystalline structure. The frequency variation of AC conductivity of CuxZn1−xS (0 ≤ x ≤ 0.1) compounds measured at different (30–300 °C) temperatures in the frequency range 5 kHz–20 MHz, showed two linear regions, (i) almost independent of frequency and (ii) an increasing region with the increase in frequency. Dielectric constant of all the compounds, measured at low frequencies, found to decrease with the increase in frequency and later, at higher frequencies it remained constant. The results are explained based on the copper interstitial defects formed due to addition of Cu into ZnS compound.

Cd 0.8 Zn 0.2 S: Na x ( x = 0, 0.03, 0.1, 0.2 and 0.3 mol%) samples have been synthesized by controlled co-precipitation technique. The samples are characterized by X-ray diffraction (XRD). DC conductivity studies were performed in the temperature region 77–300 K by using two probe method. The DC conductivity plots show the Arrhenius behavior and they exhibited VRH conduction mechanism. From the impedance, and dielectric measurements parameters like bulk resistance ( R g ), capacitance ( C g ), relaxation time ( τ ) and dielectric constant ( e ′) were calculated. The relaxation time of Na doped Cd 0.8 Zn 0.2 S samples were found to increase with the increase in temperature and varied non linearly with the increase in Na content. AC conductivity of the samples was found to increase with the increase in frequency whereas dielectric constant was observed to decrease with the increase in frequency. The results were explained based on the defects and their complexes.

Cd0.8-xPbxZn0.2S ( x= 0-0.8 ) semiconductor powders have been prepared by controlled Co-precipitation Method in an alkaline medium using Thiourea as a sulphide source. Pellets of these powders are sintered at 800 0 C for 2hours in Nitrogen atmosphere. X-Ray Diffractograms of these samples showed that they possess polycrystalline nature and its phase varied from Hexagonal to Cubic. Lattice parameters of all the compounds are determined. The dc electrical Conductivity of these bulk pellets has been studied using the Keithley electrometer over the temperature range 77-300K. It is observed that electrical conductivity increases with the increase in Pb concentration. The electrical conductivity measurements show that Cd0.8-xPbxZn0.2S compounds possess mixed conduction at low temperatures and is observed that the conductivity of Cd0.8-xPbxZn0.2S, mixed Semiconductors is enhanced with the inclusion of Pb. The results are explained based on the defects included by Pb atoms.

Nanocomposite particles of poly(chlorotrifluoroethylene-co-ethylvinyl ether) [poly(CTFE-co-EVE)]/poly(styrene acrylate) (PSA)/SiO2 were prepared with poly(CTFE-co-EVE)/PSA [CS(FS); core–shell (CS) fluoro surfactant (FS)] and hydrophilic SiO2 nanoparticles by a solution mixing method. This method yielded a homogeneous dispersion of hydrophilic SiO2 nanoparticles in the CS(FS) matrix. The nanocomposite particle composition was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. A slight improvement in the thermal stability was observed and the glass-transition temperature of the nanocomposite particles increased compared with the CS(FS) matrix. A remarkable enhancement was observed in the mechanical properties with an increase in the tensile strength from 1.1 to 6.2 MPa and with an increase in the elongation at break from 209.6 to 350.1% for the films with 15 wt % SiO2. The presence of a wettable PSA shell on the fluorocore made interaction possible with SiO2; this made it more hygroscopic with a decent water uptake capacity and an enhanced water contact angle. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012

This article describes a study on thermal behavior of poly(vinylidene fluoride-chlorotrifluoroetheylene) [poly(VDF-CTFE)] copolymers as polymeric binders of specific interest for high energy materials (HEMs) composites by thermal analytical techniques. The non-isothermal thermogravimetry (TG) for poly (VDF-CTFE) copolymers was recorded in air and N2 atmospheres. The results of TG thermograms show that poly(VDF-CTFE) copolymers get degrade at lower temperature when in air than in N2 atmosphere. In the derivative curve, there was single maximum degradation peak (Tmax) indicating one-stage degradation of poly(VDF-CTFE) copolymers for all the samples. The other thermal properties such as glass transition temperature (Tg) and degradation temperature (Td) for poly(VDF-CTFE) copolymers were measured by employing differential scanning calorimeter (DSC) technique. The kinetic parameters related to thermal degradation of poly(VDF-CTFE) copolymers were investigated through non-isothermal Kissinger kinetic method using DSC method. The activation energies for thermal degradation of poly(VDF-CTFE) copolymers were found in a range of 218–278 kJ/mol. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Core shell latex particles with a glassy core and a low Tg polymeric shell are usually preferred. More so, the glassy core happens to be a fluoropolymer with a shell polymer that helps in processability. We describe here the preparation and characterization of core shell nanoparticles consisting of poly(chlorotrifluoroethylene-co-ethylvinylether) as core encapsulated in poly(styrene-acrylate) copolymer shell using seeded emulsion polymerization method under kinetically controlled monomer starved conditions. Properties of the emulsion using surfactants (fluoro/conventional) and surfactant free conditions were investigated. Average size (100 nm), spherical shape and core–shell morphology of the latex particles was confirmed by dynamic light scattering and transmission electron microscopy. Absence of CF and CCl peaks in X-ray photoelectron spectroscopy proves that cores are completely covered. Polymerization in the presence of fluorocarbon surfactant was found to give optimum features like narrow size distribution, good shell deposition and no traces of agglomeration. Films of core shell latex particles exhibited improved transparency and enhanced water contact angles thus making them suitable for applications in various fields including coatings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A highly regioselective reduction of epoxy allylic alcohols to chiral butadienyl alcohols and its application to taxol skeleton is described.

A highly regiospecific reduction of vinyl epoxides to allyl alcohols with Cp2TiCl is described.

A highly regiospecific reduction of vinyl epoxides to allyl alcohols with Cp2TiCl is described.

First total synthesis of (2E,4E,8E,10Z)-N-(2-methyl propyl)-2,4,8,10-dodecatetraene amide ( 1 ), by the condensation of (4E,6Z)-octadienyl phenyl sulfone ( 2 ) and ethyl-4-oxobutanoate ( 3 ) followed by double elimination reaction, which involves easily accessible reagents and simple transformations is described.

The structure of the title compound, 6,7,7-trimethyl-1-(3-oxobutyl)bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid anhydride, C 17 H 22 O 4 , a Diels-Alder reaction product of β-ionone and maleic hydride, was solved by direct methods. The three six-membered rings of the bicyclo[2.2.2]oct-5-ene cage all slightly deviate from ideal boat conformations. The 3-oxobutyl side chain has an extended configuration.

A one to ten adduct of C60 and 2-methylaziridine was prepared and copolymerized with Novolac, Epon and Bisphenol A to obtain three dimensional polymers containing C60 with low coefficients of friction and good wear properties, which bode well for their potential use as solid lubricants.

First total synthesis of (2E,4E,8E,10Z)-N-(2-methyl propyl)-2,4,8,10-dodecatetraene amide ( 1 ), by the condensation of (4E,6Z)-octadienyl phenyl sulfone ( 2 ) and ethyl-4-oxobutanoate ( 3 ) followed by double elimination reaction, which involves easily accessible reagents and simple transformations is described.

A new titanium(III) mediated [(C5H5)2TiCl] reduction of 2,3-epoxy alcohols to alk-1-en-3-ols is described.

A new titanium(III) mediated [(C5H5)2TiCl] reduction of 2,3-epoxy alcohols to alk-1-en-3-ols is described.