Polypyrrole/graphene composite films synthesized via potentiostatic deposition

A one-step electrochemical process has been employed to synthesize composite films of polypyrrole/graphene (PPy/GR) by electrochemical polymerization on indium tin oxide (ITO) from an aqueous solution containing pyrrole monomer, graphene oxide (GO) nanosheets and sodium p-toluenesulfonate (NapTS). Thermogravimetric analysis (TGA) confirmed the formation of a composite; the degradation temperature of the new hybrid was between those of PPy and GO. Moreover, the bulbous surface of PPy and the almost transparent tissue-like GO nanosheets were replaced by the new appearance of the composite where the surface was flat but creased. As GO is nonconductive, we deduced that it had been reduced to conducting graphene in the composite film during the electrodeposition process, based on an electrical conductivity study measured with a four-point probe. On average, the electrical conductivity of the PPy/GR composites was twofold higher than that of the pure PPy film, indicating that the incorporation of graphene was able to enhance the conductivity of PPy film

タンソ センイ キョウカ ジュシケイ フクゴウ ザイリョウ ニオケル カイメン オヨビ カイメンソウ ノ キノウ カイメイ ト コウゾウ セイギョ ニカンスル ケンキュウ

博士(工学)同志社大学炭素繊維強化樹脂系複合材料(CFRP)の界面あるいは界面層においては、CFの陽極酸化処理条件やサイジング剤の存在により、その化学的、物理的な機能が影響を受け、CFとマトリックス樹脂との接着性やCFRPの機械的特性に影響を及ぼすことを明らかにした。また、界面/界面層の化学的、物理的機能を把握し、その構造制御を行うことにより、CFRPの優れた機械的特性を有効活用できることを示した。Chemical and physical functions of interface/interphase of CFRP are affected by the condition of surface treatment of CF and the existence of sizing resin and consequently will make some significant effects on the mechanical properties of CFRP. In order to make the best use of the superior mechanical properties of CFRP, it is important to know the chemical/physical functions of interface/interphase of CFRP and control their strctures

Wetting property of Fe‐S melt in solid core: Implication for the core crystallization process in planetesimals

In differentiated planetesimals, the liquid core starts to crystallize during secular cooling, followed by the separation of liquid–solid phases in the core. The wetting property between liquid and solid iron alloys determines whether the core melts are trapped in the solid core or they can separate from the solid core during core crystallization. In this study, we performed high-pressure experiments under the conditions of the interior of small bodies (0.5–3.0 GPa) to study the wetting property (dihedral angle) between solid Fe and liquid Fe-S as a function of pressure and duration. The measured dihedral angles are approximately constant after 2 h and decrease with increasing pressure. The dihedral angles range from 30° to 48°, which are below the percolation threshold of 60° at 0.5–3.0 GPa. The oxygen content in the melt decreases with increasing pressure and there are strong positive correlations between the S + O or O content and the dihedral angle. Therefore, the change in the dihedral angle is likely controlled by the O content of the Fe-S melt, and the dihedral angle tends to decrease with decreasing O content in the Fe-S melt. Consequently, the Fe-S melt can form interconnected networks in the solid core. In the obtained range of the dihedral angle, a certain amount of the Fe-S melt can stably coexist with solid Fe, which would correspond to the “trapped melt” in iron meteorites. Excess amounts of the melt would migrate from the solid core over a long period of core crystallization in planetesimals