Advanced Materials Research Vol. 739

Abstract: Branched copolymer of lactic acid/bicine (N, N-bis (hydroxyethyl) glycin) was prepared directly by melt polycondensation from lactic acid and bicine. The branched structure of copolymer of lactic acid/bicine was characterized by ¹H NMR and intrinsic viscosity. Although the molecular weigh of copolymer was lower than that of homopolymer of lactic acid, the hydroxyl number of the copolymer was higher than that of homopolymer. All the data indicated the molecule structure of copolymer was branched. Compared with homopolymer of lactic acid, the crystallinity of the branched copolymer decreased and the thermal stability increased.

Abstract: The growth history of a large diamond crystal synthesized by HPHT temperature gradient method was reconstructed by the defects features in the crystal. The crystal defects were revealed using white synchrotron radiation topography. Dislocations originated from the surfaces of the seed and extended along the directions of <100> were observed within the crystal grown at the early stage. The crystal was then grown to the [00-direction at the middle growing stage and no dislocations were generated at this stage. A lot of dislocation bundles were generated at the last growth stage of the crystal and each bundle was composed of several straight extended dislocations originated from the same point and extended radially within a sector of about thirty degrees centigrade. The origins of the dislocation bundles were distributed near the surface of the crystal. Most of the dislocation bundles were generated near the (-100), (010) and (00-1) and extended to the [-10, [01 and [00-, approximately. The generation of the dislocation bundles was caused by the rapid descent of the temperature in the last growth stage of the diamond crystal.

Abstract: Study of aluminum / silicon compound reduction nitridation synthesis of bauxite-based β -Sialon reaction process, using mass change ratio of the specimens and XRD, SEM, EDS analysis. The results were compared with the specimens separately using Al and Si reducing agent.The results show that:at 1100 only Al reacts with N₂ and SiO₂ to form AlN and Si; At 1200~1350°C, Si takes part in reduction-nitridation with subsequent formation of SiAlON；At 1450~1550°C，there is noticeable increase in β-SiAlON formation, the appropriate temperature is 1500°C.The amount of β-SiAlON formed is higher and crystale growth is better than that of single reducing agent.

Abstract: Five kinds of unsupported MoS₂ hydrodesulfurization catalysts and the precursor of MoS₂ catalyst, nanosized MoO₃, were synthesized by a novel hydrothermal reduction method. The influence of temperature, concentration of reactants and pH values on the growth morphology of MoS₂ was systematically investigated. The MoS₂ fibers showed lots of defects and they were easily bended, which increased the number of active sites on the catalyst and easily met the requirements of hydrotreating ultra-desulfurization of fuel oil.

Abstract: Carbon-coated, bismuth-doped, lithium iron phosphates, LiFe_1xBi_xPO₄ (0x0.05), have been synthesized by a solid-state reaction method. From the optimization, the carbon-coated LiFe_0.95Bi_0.05PO₄ phase showed superior performances in terms of phase purity and high discharge capacity. The structural, morphological, and electrochemical properties were studied and compared to carbon-coated, LiFePO₄. The Li/LiFe_0.95Bi_0.05PO₄ with carbon coating cell delivered an initial discharge capacity of 145 mAh/g and was 30 mAh/g higher than the Li/LiFePO₄ with carbon coating cell. Cyclic voltammetry revealed excellent reversibility of the LiFe_0.95Bi_0.05PO₄ with carbon coating material. High rate capability studies were also performed and showed a capacity retention over 93% during the cycling. It was concluded that substituted Bi ion play an important role in enhancing battery performance of the LiFePO₄ material through improving the kinetics of the lithium insertion/extraction reaction on the electrode.

Abstract: A novel Zn complex [Zn (C₁₂H₈N₂)(C₄H₄O₅)(H₂O)](H₂O) has been synthesized from a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Zn atom is six-coordinated by two phenanthroline N atoms, three O atoms from malic acid anion and one O atom from water. The crystal packing is stabilized by O-H...O hydrogen bonding interactions.

Abstract: The complex C₂₈H₃₂CaCoN₄O₂₄ has been synthesized from hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Co atom is six-coordinated by two N atoms, four O atoms from two 2,6-pyridinedicarboxylic acid. The Ca atom is eight-coordinated by two N atoms, six O atoms from two 2,6-pyridinedicarboxylic acid and two water molecular. The crystal packing is stabilized by O-H...O hydrogen bonding interactions.

Abstract: A manganese oxide, Mn₃O₆(H₂O)₂ has been synthesized from a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Mn1 atom is coordinated by four O atoms. The Mn2 atom is coordinated by six O atoms. The molecular structure stabilized by the O-H...O hydrogen-bonding interactions.

Abstract: Polycarbonate/poly (lactic acid)/(PC/PLA) blend is a kind of novel potential material for introducing the degradability of PLA to high performance PC. However, the bad compatibility between PC and PLA results in poor impact resistance and strength, which limits its applications. For resolving the problem, linear low density polyethylene (LLDPE) was added into blend to improve the mechanical properties, especially the toughness. Meantime, nanosized montmorillonite was also used as an additive for modifying the blend. The results showed that the the tensile and impact strength, the elongation at break of PC/PLA all be improved with the increase of LLDPE, the nanosized montmorillonite could also increase the strength of blends when the content is lower than wt5% of blends.