Using 1,3,5,9-tetrabromo-7-tert-butylpyrene as the bromide precursor, a series of novel butterfly-shaped 1,3,5,9-tetraaryl substituted pyrene derivatives were synthesized by the Suzuki-Miyaura cross-coupling reaction. Their thermal, photophysical, electrochemical and related properties were systematically investigated. All compounds were found to exhibit high thermal stabilities with decomposit...

MgFe2O4 nanoparticleswere synthesized by a solution combustion technique, taking precursor nitrate and fuel in appropriate ratio and TiO2 nanoparticles are prepared by wet grinding technique and the composition of MgFe2O4/TiO2 nanoceramic prepared by mechano chemical synthesis and are taken in equal wt%, x=0.5. The process was a simple, convenient, environment friendly, inexpensive and efficien...

We present the temperature dependence of the growth rate of carbon nanofibers by plasma-enhanced chemical vapor deposition with Ni, Co, and Fe catalysts. We extrapolate a common low activation energy of 0.23-0.4 eV, much lower than for thermal deposition. The carbon diffusion on the catalyst surface and the stability of the precursor molecules, C2H2 or CH4, are investigated by ab initio plane w...

Nanoporous silica cryogels with a high specific surface area of 1095 m2 g-1 were fabricated using tert-butyl alcohol as a reaction solvent, via a cost-effective sol-gel process followed by vacuum freeze drying. The total time of cryogel production was reduced markedly to one day. The molar ratio of solvent/precursor, which was varied from 5 to 13, significantly affected the porous structure and...

The thermal degradation of tyrosine at a residence time of 0.2s was conducted in a tubular flow reactor in flowing N2 and 4% O2 in N2 for a total pyrolysis time of 3min. The fractional pyrolysis technique, in which the same sample was heated continuously at each pyrolysis temperature, was applied. Thermal decomposition of tyrosine between 350 and 550°C yielded predominantly phenolic compounds (...

Textural evolution in sol-gel derived nanostructured unsupported titania membranes has been studied using differential scanning calorimetry (DSC), differential thermal analysis (DTA), thermal gravimetry (TG), X-ray diffraction (XRD) and N, adsorption. The anatase-to-rutile phase transformation kinetics were studied using the Avrami model. The precursor gel had a surface area of ca. 165 m2 g-', ...

Oxyfluoride lead borate glasses singly doped with Nd3+ and Er3+ ions have been studied before and after thermal treatment. The orthorhombic PbF2 crystallites are formed during thermal treatment, which was evidenced by X-ray diffraction analysis. Near-infrared luminescence spectra at 1.06 μm and 1.53 μm have been registered for samples before and after annealing, which correspond to the main F3/...

Thermoelectric materials have generated interest as a means of increasing the efficiency of power generation through the scavenging of waste heat. Materials containing nanometer-sized structural and compositional features can exhibit enhanced thermoelectric performance due to the decoupling of certain electrical and thermal properties, but the extent to which these features can be controlled is...

Metal oxide nanomaterials are important and excellent materials, because of its special properties like chemical stability, high photo catalytic activity, high electric permittivity, non-toxic nature. So it is used in various applications like optical, electrical, electronic, antiseptic, antibacterial, environmental, semi conductors and catalytic devices. Present work focused on to synthesis of...

We present the electronic structure evolution from graphite oxide to thermally reduced graphite oxide. Most functional groups were removed by thermal reduction as indicated by high resolution X-ray photoelectron spectroscopy, and the electrical conductivity increased 6 orders compare with the precursor graphite oxide. X-ray absorption spectroscopy reveals that the thermally reduced graphite oxi...