Ceramic membranes are a type of artificial membrane

Artificial membrane

An artificial membrane, or synthetic membrane, is a synthetically created membrane which is usually intended for separation purposes in laboratory or in industry. Synthetic membranes have been successfully used for small and large-scale industrial processes since the middle of twentieth century. A...

s made from inorganic materials (such as alumina, titania

Titanium dioxide

Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...

, zirconia oxides or some glassy materials). They are used in membrane operations.

By contrast with polymeric membranes

Polymeric membranes

Polymeric membranes are membranes that take the form of polymeric interphases, which can selectively transfer certain chemical species over others. There are several mechanisms that could be deployed in their functioning. Knudsen diffusion and solution diffusion are prominent mechanisms. Polymeric...

, they can used in separations where aggressive media (acids, strong solvents) are present. They also have excellent thermal stability which makes them usable in high-temperature membrane operations.

Like polymeric membranes, they are either dense or porous.

Dense membranes

Dense ceramic membranes are used for the purpose of gas separation. Examples are the separation of oxygen from air, or the separation of hydrogen gas from a mixture.

Porous membranes

Porous ceramic membranes are chiefly used for gas separation

Gas separation

Gas mixtures can be effectively separated by synthetic membranes. For other methods see adsorption, absorption, cryogenic distillation.Membranes are employed in:* separation of nitrogen or oxygen out of air...

 and micro-

Microfiltration

Microfiltration is a membrane technical filtration process which removes contaminants from a fluid by passage through a microporous membrane. A typical microfiltration membrane pore size range is 0.1 to 10 micrometres...

 or nanofiltration

Nanofiltration

Nanofiltration is a relatively recent membrane filtration process used most often with low total dissolved solids water such as surface water and fresh groundwater, with the purpose of softening and removal of disinfection by-product precursors such as natural organic matter and synthetic organic...

. They can be made from both crystalline as well as amorph

Amorph

Amorph may refer to:*Muller's morphs*Amorphous*Carbosilicate Amorphs, a fictional species...

ous solids.

An example of an amorphous membrane is the silica membrane .