Main Page | See live article | Alphabetical index A membrane is a thin, typically planar structure or material that separates two environments. Because it sits between environments or phases and has a finite volume, it can be referred to as an interphase rather than an interface. Membranes selectively control mass transport between the phases or environments. Biological membranes include: cell membrane mitochondrial membrane Artificial membranes are used in: Reverse osmosis Ultrafiltration Microfiltration Pervaporation Dialysis Electrodialysis Emulsion liquid membranes Membrane-based solvent extraction Membrane reactors Gas permeation supported liquid membranes This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.