mass transfer

This term is a specialized technical expression used primarily in chemical engineering, physics, and biochemistry. It describes the physical process of transporting matter from one phase to another or within a single phase, driven by a concentration gradient. It is distinct from heat transfer, though the two processes often occur simultaneously in industrial reactors.

In professional discourse, the term is typically used as an uncountable noun when referring to the general phenomenon or the theoretical study of the process. It is rarely pluralized unless referring to multiple distinct types or mechanisms of transfer across different systems.