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This work covers the effects of annealing temperature on crystalline size, surface morphology, optical, structural and paramagnetic properties of NiS and Ni 3 S 4 nanostructures grown through SILAR technique into FNBR matrix. Annealing at low temperature was performed in air and vacuum for 8 h. X-ray diffraction results confirm structural phase transitions (like NiS→Ni 7 S 6 and Ni 3 S 4 →Ni 9 S 8 ) and oxidation processes (by the formation of NiO-SO 4 -H 2 O) after thermal annealing of nanocomposites (NCs) in a vacuum and in air, respectively. By EDX spectrum the average Ni:S atomic ratio is approximately 1:1 for as-prepared NiS, 1:0.89 for NiS annealed in a vacuum and 1:0.91 for NiS annealed in air. [ABSTRACT FROM AUTHOR]

Cu x S-Ni y S z /FNBR and CuS-Ni y S z /FNBR nanocomposites (NCs) were prepared from β-NiS/FNBR by ion exchange method and dielectric characterized. Dielectric properties of NCs were investigated at the temperature of 26 °C–120 °C in 120–10 6 Hz frequency range. With measuring electric capacity and resistance of the samples at different frequency we have studied the dielectric permittivity, dielectric loss tangent, dielectric modulus, conductivity, relaxation times and Cole-Cole plots were obtained. At 120 °C measurement temperature, some of the destruction processes in polymers affect to interfacial interaction between the polymer and particles surface. After high temperature measurement all three samples were cooled to room temperature and their dielectric measurements were carried out at room temperature. It is observed that at high measurement temperature some of carriers transfer from one energy level to another and the dipole orientation did not return completely to the previous situation. [ABSTRACT FROM AUTHOR]

Nickel sulfide nanostructures have been successfully prepared with two different sulfur sources like thiourea (S C(NH 2 ) 2 ) and sodium sulfide by the successive ionic layer adsorption and reaction (SILAR) method. The functionalized nitrile-butadiene rubber (F-NBR) was used as stabilizing agent for formation of nickel sulfide semiconductor nanoparticles. The nanoparticle sizes correspond to 8.5 nm and 7 nm using thiourea and sodium sulfide respectively. The as-synthesized NiS and Ni 3 S 4 nanostructures were characterized by XRD, SEM, EDX, UV–vis and FTIR spectroscopy methods. A systematic investigation of the final end products has been done to elucidate the formation mechanism at different experimental parameters. Using thiourea the optical band gap of NiS for 4, 6 and 8 cycles were determined to be 3.12, 2.93 and 2.81 eV, respectively. The optical band gap of Ni 3 S 4 for 6 and 8 cycles were determined to be 2.8 and 2.15 eV, respectively. [ABSTRACT FROM AUTHOR]

Abstract: In this research work, we have presented a chemical method to elaborate the PbS, CuS nanocrystals embedded in a polymer composites matrix. We have used polyethylene and nitrile butadiene rubber PE/NBR as a support for synthesis of lead sulfide (PbS) and copper sulfide (CuS) nanocrystals. The size control and morphology of these (PbS and CuS) nanoparticles have been applied by the method of “layer by layer”. The obtained nanoparticles were characterized by X-ray diffraction (XRD), UV–Vis and Atomic Force Microscopy (AFM). UV–Vis spectroscopy was used to determine simple optical responses, getting the biggest transmittances of CuS and PbS nanoparticles. Measured size of CuS nanoparticles is approximately 5.5–90nm in different dose. X-ray diffraction (XRD) study confirmed the formation of cubic phase of PbS nanocrystals into the composite matrix. The size of PbS was estimated ∼9nm. The surface morphology and crystallite sizes were determined by Atomic Force Microscopy measurements. [Copyright &y& Elsevier]