Tsuyoshi Asano

Surface active species and their reaction schemes in extraction solution systems identified from practical behaviors of interfacial tension

Abstract The interfacial tensions in two-phase solution systems for extraction of metallic ions from aqueous phase to organic phase by di(2-ethyl-hexyl) phosphoric acid were measured by the Wilhelmy plate method and partly by laser-light scattering method to confirm the accuracy. For copper and iron extraction solution systems, the surface-active species and their interfacial concentrations were identified by comparing the actual behavior of interfacial tension, the pH and extractant concentration dependencies, with the Gibbs–Langmuir equation for adsorption. It was shown that the extractant molecules should be adsorbed at the interface in the form of monomer and its dehydrogenated anion and that in copper extraction solution system non-surface-active 1:2 intermediate complexes should be formed, and in iron extraction solution system strongly surface-active 1:2 intermediate complexes should be formed at the interface. Based on the insights related to the intermediate complexes, reaction schemes at the interface are also discussed.

Evacuation Characteristics of Screw-Grooved Molecular Pump.

ねじ溝型分子ポンプのロータ矩形溝部およびスリーブ間隙における気体の流れに対する線形化Boltzmann方程式の数値解析結果を平滑化理論に適用して, 分子ポンプ内の圧力場を解析し, 到達圧力, 排気速度およびロータ回転数の関係を明らかにした.合わせて, ねじ溝分子ポンプを試作し, 補助圧力およびロータ回転数に対する到達圧力および排気速度を測定し, 計算結果と比較検討するとともにポンプの排気特性について考察した.また, 気体の種類による排気特性の差異についても明らかにした.