Vesicular Biomimetic Membranes for Metal Recovery

本课题研究了一种基于囊泡膜的仿生 从水溶液中除去有害金属阳离子的系统 溪流 在初步工作中，PI使用了平衡 洗涤剂透析以制造单层囊泡， 含有亲脂性金属的大豆磷脂酰胆碱 载体，离子感音器A23187，在囊泡膜中，和 囊泡中的螯合剂（NTA，次氮基三乙酸盐） 内政 当将囊泡分散体与聚乙二醇混合时， 含有金属阳离子的水溶液，所述阳离子 与膜中的金属载体结合。 的 复合物可溶于膜中，并且它扩散穿过膜。 膜囊泡的内表面， 释放金属离子。 释放的离子与 螯合剂，从而保持离子的浓度， 囊泡内表面的亲脂复合物 膜非常小。 由于该值较小， 力的扩散的额外的络合物的离子和 亲脂体仍然很大，囊泡继续强烈地 吸收金属离子。 批实验的结果，其中 囊泡是仅含Cu（II）的混合溶液， Cd（II）或Pb（II）阳离子表明囊泡是 这些金属离子的有效清除剂，具有快速吸收和 高负荷。 这种技术的主要问题是成本高， 亲脂性载体和磷脂酰胆碱。 的 拟议的研究将探索成本较低的亲脂性载体 例如裂型金属粘合剂和冠醚基 试剂和用于囊泡的较便宜的组分， 烷基苯磺酸盐表面活性剂 竞争性金属离子 吸收也将进行研究，并在实验室规模的连续 金属回收系统将测试使用中空纤维 膜盒，以接触囊泡分散体和囊泡分散体。 以逆流模式排出废物流。

This proposal studies a vesicular membrane based biomimetic system for removing hazardous metals cation from aqueous streams. In preliminary work, the PI has used equilibrium detergent dialysis to fabricate unilamellar vesicles made of soybean phosphatidylcholine harboring a lipophilic metal carrier, the ionophone A23187, in the vesicle membrane, and a chelating agent (NTA, nitrilotiacetate) in the vesicle interior. When the vesicle dispersion is mixed with an aqueous solution containing the metal cations, the cations become bound to the metal carrier in the membrane. The complex is soluble in the membrane, and it diffuses across the lamella to the inside surface of the membrane vesicle where the metal ion is released. The released ion complexes with the chelator, thereby keeping the concentration of the ion- lipophile complex at the inside surface of the vesicle membrane extremely small. With this value small, the driving force for diffusion of additional complexes of the ion and the lipophile remains large, and the vesicle continues to strongly uptake the metal ions. Results of batch experiments in which the vesicles were mixed solutions containing only Cu(II), Cd(II), or Pb(II) cations demonstrate that the vesicles are effective scavengers of these metal ions with rapid uptake and high loading. The primary problem with this technique is the high cost of the lipophilic carrier and the phosphidylcholine. The proposed research will explore less costly lipophilic carriers such as cleft type metal binding agents and crown ether-based agents, and less costly components for the vesicles such as alkyl benzene sulfonate surfactants. Competitive metal ion uptake will also be studied, and a bench scale continuous metal recovery system will be tested which uses hollow fiber membrane cartridges to contact the vesicle dispersion and the waste stream in a countercurrent mode.