Specific surface area

The specific surface area indicates the amount of surface area available per unit of mass or volume in a material. It is typically expressed in m²/g, m²/mg or m²/µg and describes the amount of surface area available per unit of mass or volume in a substance. In powder technology, the specific surface area is a key parameter for the fineness and reactivity of a material.

High specific surface areas are found in fine-grained powders, porous solids and nanostructured materials. They influence adsorption, reaction rates, sintering behaviour, flow properties and mixing behaviour. Fine particles with a large specific surface area often exhibit increased cohesion and a tendency to agglomerate.

In practice, the specific surface area is often determined using the BET method (Brunauer–Emmett–Teller nitrogen adsorption). The specific surface area is an important parameter for characterising powders, catalysts, fillers and additives.