Supported Ionic Liquid Membranes for Metal Separation

Abstract

Metals are widely used in various areas of human life, and their existence in the environ‐ ment at high concentrations has become a cause for concern. Metals can enter the human body and disturb the human metabolic system. Therefore, research to recover metals from their matrix both from industrial wastewater and from ores or scraps containing metals is of great importance. One of the separation techniques proposed to overcome those issues involves using supported ionic liquid membranes (SILMs). This chapter summarizes the recovery of metals using SILM. In SILM, an ionic liquid that acts as an extractant is embedded in small pores of a polymer support. The latest type of physical impregnation of ionic liquid, which is the type most commonly used in metal separation, is called polymer inclusion membrane (PIM). PIMs were prepared by casting a solution containing an ionic liquid, a plasticizer and a base polymer to form a thin, flexible and stable film. A PIM including ionic liquids has a similar configuration to SILM, and it is considered to be a kind of SILM. In this chapter, effects on the stability and selectivity in SILM and PIM for metal separation are reviewed.