A01 KI-NaHCO₃溶液中のI^-の酸化速度に対するKI濃度効果

抄録

A sonochemical reaction depends on the kind of gas dissolved in the reaction field, namely, in the reactant solution. In former paper, we reported an improvement of sono oxidation rate of KI solution in a CO₂-Ar system. To study the effect of CO₂ existing under alkaline condition, sonication was performed in a NaHCO₃-KI solution. Sonication was carried out in a system with a 200 kHz transducer (KAIJO, QUAVA mini QR003, 50 W). The reactants comprised several concentrations of KI aqueou s solution. Before sonication, the reactor was filled with Ar gas and a certain amount of NaHCO₃ was dosed to the solution. Sono-oxidation rate was evaluated by KI dosimetry (λ_max = 355 nm, JASCO V730). In the cases of no addition of NaHCO₃ a weak absorbance, namely, a slow rate of sono oxidation was observed. On the other hand, in spite of the alkaline solution, the system with dissolved NaHCO₃ had the highe st absorbance We considered sono oxidation activity would be enhanced by CO₂ produced from NaHCO₃. However, effect of KI concentration on sono-oxidation rate in NaHCO₃-KI system was different from that in CO₂-Ar system.