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Microcapsules containing tri-n-octylamine as an extractant with the diameter of less than 25μm were prepared by using SPG membrane emulsification and insitu polymerization method. The morphologies of microcapsules, the encapsulation efficiencies of tri-n-octylamine, the extraction properties of palladium （II） from hydrochloric acid solution and the back extraction properties of palladium （II） from microcapsules were investigated. The average diameter of obtained microcapsules was about half of the pore diameter of SPG membrane. The encapsulation efficiency of tri-n-octylamine was approximately 100% for all the microcapsules prepared in this study. Therefore, it can be said that there was practically no loss of tri-n-octylamine during the preparation of microcapsules. All microcapsules prepared in this study reached forward extraction equilibrium within 5 minutes and the forward extraction ratio reached nearly 1. The back extraction of palladium （II） from microcapsules was carried out using 0.1M-hydrochloric acid solution containing a prescribed amount of thiourea. The back extraction occurred promptly and the back extraction ratio was high enough to elute all palladium （II） out from the microcapsules. Furthermore, by repeating forward and back extraction experiments, the durability of microcapsules was examined. From the result, it can be said that tri-n-octylamine was encapsulated rigidly and there was no leakage during extraction and back extraction experiment. Thus it seemed that the microcapsules were capable to be used in a repeated operation.

application/pdf ギ酸濃度が銅の腐食に及ぼす影響を調べるため，濃度1～10000 mg/L ギ酸溶液中に銅管を最長84日間浸漬した．試験溶液中の銅イオン濃度を測定し，銅溶出速度を求めた．1～1000 mg/L ギ酸溶液中の銅イオン濃度はある一定値に飽和する一方，5000，10000 mg/L ギ酸溶液中の銅イオン濃度は浸漬日数の増加とともに上昇する．84日間浸漬後の銅管に発生した腐食の形態は，1～1000 mg/L ギ酸溶液の場合は蟻の巣状腐食であり，5000，10000 mg/L の場合は全面溶解であった．試料の重量減は溶液のギ酸濃度が増すにつれて増加する傾向を示した．Copper tubes were immersed in formic acid solutions ranging in concentration from 1 to 10000 mg/L for up to 84 days to investigate the effect of concentration of formic acid on copper corrosion. Concentrations of copper ion in test solutions were measured to determine the dissolution rate of copper. Concentrations of copper ion in formic acid solutions from 1 to 1000 mg/L were saturated in a certain value, while concentrations of copper ion in 5000 and 10000 mg/L formic acid solutions increase with an increase in immersion period. Corrosion form of copper tubes soaked in formic acid solutions from 1 to 1000 mg/L was an ant's nest corrosion, while the uniform attack occurred on copper tubes soaked in 5000 and 10000 mg/L formic acid solutions. Weight losses of specimens have a tendency to increase with increasing concentration of formic acid.