Advanced Materials Research Vols. 785-786

Abstract: An organic emitting device with well structure is reported. The well structure fabricated by alternating deposition of constituent tris-(8-hydroxyquinoline) aluminum (Alq) and 4, 7-diphenyl-1, 10-phenanthroline (BPhen) layers improved the current efficiency. The enhanced efficiency can be attributed to the strong accumulation of electrons and holes in the emitting layer, which leads to an increase of the exciton formation and exciton recombination probability. The single well device exhibits the highest current efficiency of 4.12cd/A at 4V, which is more than 1.2 times than that of the conventional organic light-emitting devices. It is an effective and simple way to improve the efficiency of the organic devices by utilizing well structure as the emitting layer with proper well number.

Abstract: A new attempt to suppress oil fire with a temperature-sensitive hydrogel was examed. The hydrogel were prepared by free radical polymerization methods with N-isopropy-lacrylamide (NIPAm) and Sodium acrylate (AA-Na). Different mass fractions of the aqueous hydrogen were measured by a differential scanning calorimeter (DSC) and viscosity tester. A series of gasoline fires were suppressed with hydrogel extinguishing agent B of Zhejiang University and the temperature-sensitive hydrogel respectively. The whole suppressing experiment was recorded by a digital video, four heat probes and eight thermocouples. It showed that the temperature-sensitive hydrogel has shorter extinguishment time and faster cooling rate than the hydrogel B, The extinguishing agent residual after the suppressing were observed by SEM, massive microporous structures were found in the temperature-sensitive hydrogel.

Abstract: Based on the thermal stability test on the different fire resistance materials, this article study the Thermal protection property (TPP) of the different materials composite structure and analyses the effect that the materials changes on the TPP of the composite structure products. The results indicate that the thermal insulation batts made by Aramid fiber materials have excellent thermal stability, adding a certain percentage of Aramid fiber 1414 into the thermal insulation batts makes for the batts having stably insulation function, and it only needs 10% around additive amount to satisfy this demand, compared with polyimide and PPS, Aramid fiber 1414 have better thermal stability when encountered fire.

Abstract: To achieve lower price and high performance of pitch carbon fiber, coal tar pitch has to restructure through high-purity process, thermal and acid treatment process, and separation process. Thermal treatment and different oxidation treatments were used to increase the softening point and yield of the precursor pitch for carbon fiber. These treatments have the effect on the properties of carbon fiber because they cause considerable change in the chemical composition of pitches. Low molecular weight materials could be removed by the thermal treatment. The oxygen containing structure formed by the acid treatments would promote the poly-condensation and polymerization reactions. The oxidation treatment with sulfuric acid, nitric acid, and air blowing would lead to the remarkable change in the chemical composition of pitches, and resulted in considerable increase in the softening point and yield of the pitches.

Abstract: Activated carbon is a kind of material with many pores and large specific surface. Activated carbon has been widely applied in many fields for its excellent adsorption and steady chemical characters. Activated carbon was prepared with apricot shell as raw materials by the sequence of crushing, screening, carbonization and activation. To improve adsorption ability of activated carbon, KOH was added as a activator into the carbonization materials. The effect of carbonization and activation conditions on benzene value and Vitamin B₁₂ value were investigated. Benzene value and Vitamin B₁₂ value of activated carbon were improved from 163.01mg.g^-1 and 19.16mg.g^-1 to 589.14mg.g^-1 and 35.02mg.g^-1, respectively.

Abstract: butyl titanate, water and anhydrous ethanol were used as raw materials; Cerium-doped TiO₂ was prepared by sol method at room temperature. Then it was characterized by X ray diffraction, Raman spectra, Uv-vis absorption spectra and Scanning Electron Microscope. The results show that TiO₂ crystal can be got by sol method at room temperature. Cerium-doped TiO₂ has the better catalytic performance for methyl orange.

Abstract: Activated carbon was modified with silica aerogel by the Sol-Gel. The surface characteristics and structure of activated carbon modified by the silica aerogel were characterized with N₂ adsorption method, Scanning Electron Microscope and Thermal Analysis. The experiment results show that the silica aerogel can be used to modify activated carbon for the preparation of composite. SiO₂ aerogel can effectively cover holes in the activated carbon, specific surface area of activated carbon composite modified by SiO₂ aerogel was between activated carbon and silica aerogel. When M_SiO2: M_C is 1:3, specific surface area of the composite was 758.638 m²/g; When M_SiO2:M_C is 1:2, specific surface area of the composite was 760.38 m²/g; When M_SiO2:M_C is 1:1, specific surface area of the composite was 862.755 m²/g.

Abstract: Bis (thien-2-yl) cyclopentene derivatives have been synthesized in the two routes. Upon irradiation with 313 and 405 nm light, the absorption spectrum of compound 3O and 4O did not change and clear isosbestic points appeared. These results suggest that the compounds do not decompose during the irradiation and are suitable as switches

Abstract: The flame-retardant mechanisms of aluminium hydroxide (ATH) and magnesium hydroxide (MH) that used as typical inorganic fire-retardant were illustrated. The preparation methods of the fire-retardants are reviewed. And the modification approaches and future development direction of the fire-retardants were also discussed. Although the ATH and MH are environmental friendly flame retardants, they still have drawbacks and further research is needed to improve their flame retardant properties.

Abstract: Vinylidene fluoride and trifluoroethylene [P(VDF-TrFE)] ferroelectric thin film was spin-coated on Au-coated polyimide substrate and its polarization reversal was investigated by analyzing the evolution of activation field (α) with temperature. Although α is nearly a constant between 300 and 330 K, it increases linearly when temperature rates between 200 and 230 K, and between 230 and 300 K. On the other hand, the intensity of X-ray diffraction for P(VDF-TrFE) films from 200 to 330 K indicates that glass-transition process plays a significant role in both the microstructure and the polarization reversal of P(VDF-TrFE) copolymer.