Fixed Carrier Membrane
Fixed (site) carrier membranes (FSC) combine the durability of a dense membrane with the selectivity of a supported liquid membrane (SLM) overcoming the limitation of SLM, degradation due to the wash out of the carrier solution over time. The carrier is either covalently bonded to the polymer chain (chained carrier) or immobilized in the polymer matrix by physical constraints or weaker ionic bonding. A fixed carrier membrane will separate mainly via facilitated transport mechanism, implying that the carrier will react specifically with one of the components to be separated.
Noble (1990, 1991) and Cussler (Cussler et al. 1989) developed two different models to describe the transport across fixed carrier membranes. E. L. Cussler explained the transport by “chained carrier” theory, when carriers are covalently bonded, requiring a certain mobility of polymeric chains and that a percolation threshold appears when two chained carriers are too far apart.
R. Noble described the transport of...