Low Temperature Post Radiation Polymerization of Tetrafluoroethylene in the Presence of the Graphene 3D Material

It was found that irradiation by γ-rays at the liquid nitrogen temperature of a mixture of C2F4 with the grapheme 3D material obtained by explosive exfoliation of graphite oxide gives a composite in which the concentration of polytetrafluoroethylene is 80 wt %. In the case of C2F4 polymerization under similar conditions in the absence of the carbon material, the PTFE yield is six times lower. The results of certifica-tion of both the parent carbon material and the composite obtained via polymerization are also reported. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3559

Charge and spin inhomogeneous phases in the Ferromagnetic Kondo Lattice Model

We study numerically the one-dimensional ferromagnetic Kondo lattice. This model is widely used to describe nickel and manganese perovskites. Due to the competition between double and super-exchange, we find a region where the formation of magnetic polarons induces a charge-ordered state. This ordering is present even in the absence of any inter-site Coulomb repulsion. There is an insulating gap associated to the charge structure formation. We also study the insulator-metal transition induced by a magnetic field which removes simultaneously both charge and spin ordering.Comment: 7 pages, 11 figure

Low-temperature limit of the rate of propagation of chains in the hydrobromination of ethylene

The second (after the polymerization of formaldehyde) case of the low-temperature limit of the rate of elementary acts of propagation of chains in solid phase chemical chain reactions was found by the example of hydrobromination of ethylene.The average time of the development of new link of chain (τ〇) was determined by the method of differential diathermic calorimetric between 90 and 30 K. From 90 to 70 K this time increases in accordance with the Arrhenius law (E 〜 4 kCal/Mole), while at lower temperatures τ 〇 reaches gradually the plateau value [math] 〜 0, 1 sec, and the chain length is ν 〜 800 at 40 K. The existence of long chains and the appearance of the low-temperature limit of the rate of their propagation speaks in favor of tunnel mechanism of hydrobromination of ethylene at sufficiently low temperatures