Mechanism of extractant loss in solvent extraction process (Ⅰ)——Transfer of saponified D2EHPA from organic phase to aqueous phase and its aggregation behaviour  

作　　者：王笃金 吴瑾光 李彦 翁诗甫 吴佩强 徐光宪 

机构地区：[1]State Key Laboratory of Rare Earth Materials Chemistry and Applications,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China

出　　处：《Science China Chemistry》1995年第11期1281-1287,共7页中国科学（化学英文版）

基　　金：the National Climbing Program of China

摘　　要：The phenomenon of the loss of saponified D2EHPA(di(2-ethylhexyl)phosphoric acid,HA)from organic phase to aqueous phase and its aggregation behaviour were studied with FT-IR and DLS(dynamic light scattering)techniques based on the fact that saponified extractant can form reversed micelles orw/o microemulsions in n-heptane,a non-polar diluent.The results indicate that "normal rnioelles" or o/wmicroemulsions are formed from acidic extractant and its sodium salt in aqueous phase,and the micelle ormicroemulsion drop has a non-polar core which can solubilize nheptane,so the equilibrated aqueous phasecontaining extractant is a complex fluid rather than a "real solution".Therefore,the aqueous aggregate for-mation leads to the extractant loss in solvent extraction process.Strong electrolytes can prevent or lessen theextractant loss.The results of this paper provide a theoretical possibility for solving the problem ofextractant and solvent loss in liquid-liquid extraction industry.The phenomenon of the loss of saponified D2EHPA(di(2-ethylhexyl)phosphoric acid,HA) from organic phase to aqueous phase and its aggregation behaviour were studied with FT-IR and DLS (dynamic light scattering)techniques based on the fact that saponified extractant can form reversed micelles or w/o microemulsions in n-heptane,a non-polar diluent.The results indicate that 'normal rnioelles' or o/w microemulsions are formed from acidic extractant and its sodium salt in aqueous phase,and the micelle or microemulsion drop has a non-polar core which can solubilize nheptane,so the equilibrated aqueous phase containing extractant is a complex fluid rather than a 'real solution'.Therefore,the aqueous aggregate for- mation leads to the extractant loss in solvent extraction process.Strong electrolytes can prevent or lessen the extractant loss.The results of this paper provide a theoretical possibility for solving the problem of extractant and solvent loss in liquid-liquid extraction industry.

关 键 词：D2EHPA FT-IR MICELLE MICROEMULSION EXTRACTANT LOSS 

分 类 号：O621.2[理学—有机化学]