Membranes, bulk phase interfaces and separations: Novel membranes and separation techniques

摘要

Membranes and bulk phase interfaces share a close relation in separations. The bulk phase interface may be a fluid-fluid, fluid-solid or solid-solid interface; it may be immobilized or mobile. In conventional membrane separations, two phase interfaces exist on two sides of the membrane, two solid-fluid interfaces for solid membranes. Conventional equilibrium separations however have only one bulk phase interface. Such an interface in gas-liquid, vapor-liquid, liquid-liquid, subcritical/supercritical fluid-liquid separation systems may be created by phase interface immobilization at a membrane pore mouth as in membrane contactor-based nondispersive equilibrium separations; the real-life challenges faced by such techniques will be identified. Membrane emulsification/sparging/degassing leads to dispersion-based creation of mobile phase interfaces and phase contacting. Convective transport through membrane pores provide efficient solid-liquid contacting as in membrane chromatography. Antisolvent crystallization via dispersion/mixing through membrane pores creates new mobile solid-liquid interfaces.