聚甲基丙烯酸十二酯-丙烯酸共聚物对乳状液膜中Cu^(2+)迁移的影响

Influence of Copolymer of Dodecyl Methacrylate-Acrylic Acid on Transfer of Cu^(2+) Ions through Emulsion Liquid Membrane

将两亲共聚物聚甲基丙烯酸十二酯-丙烯酸[P(DM-AA)]作为膜稳定剂加到由Span-80作表面活性剂、二-(2-乙基己基)磷酸(HDEHP)作流动载体、煤油和液体石蜡作膜溶剂及硫酸稀溶液作内相而组成的W/O型乳状液膜中,研究了此体系对Cu2+的迁移作用.结果表明,由于两亲高分子的空间稳定作用而导致乳液膜对Cu2+具有较好的迁移效果.最优条件为:在膜相中P(DM-AA)含量3.0%,Span-804.0%,HDEHP3.0%,石蜡6.0%(ω),膜相:料相=1:10(-),[H+]=1.0mol/L,接触时间6min,搅拌速率200～300r/min.此外,还探讨了乳状液膜的结构和Cu2+迁移的机理,认为其迁移属于异向耦合传输机理。

The effects of separation conditions of emulsion liquid membrane on the transfer rate of Cu^2＋ are studied. The membrane is composed of an amphiphilic copolymer of dodecyl methacrylate and acrylic acid [P（DM-AA）], sorbitan monooleate （Span-80）, di（2-ethylhexyl） phosphoric acid （HDEHP）, kerosene, paraffin oil, and an aqueous H2SO4 solution, which are used as membrane stabilizer, surfactant, carrier, solvent and internal phase, respectively. The results show that the transfer rate of Cu^2＋ is significantly improved by the steric stabilization of the amphiphilic copolymer. The optimum conditions are determined as follows： P（DM-AA） 3.0%, Span-80 4.0%, HDEHP 3.0%, paraffin oil 6.0%, volumetric ratio of membrane phase to feed phase 1：10,[H^＋]= 1.0 mol/L, contact time 6 min, and stirring rate 200-300 r/min. Moreover, the structure of the emulsion liquid membrane and the mechanism of a coupled counter-transport are also discussed.