Membranes, Phase Interfaces, and Separations: Novel Techniques and Membranes—An Overview

Abstract

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, and 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. Membrane emulsification/sparging/degassing leads to dispersion-based creation of mobile phase interfaces and phase contacting. Convective transport through membrane pores provides efficient solid−liquid contacting as in membrane chromatography. Antisolvent crystallization via dispersion/mixing through membrane pores creates new mo...