Spontaneous (irreversible) process of transfer of mass across non-homogeneous fields.
The driving force can be difference in concentration (in liquids) or partial pressure
(in gases) of the component. In fluids, mass transfer may be enhanced by turbulent
flow. In biological systems, mass transfer through membranes may result from normal
, facilitated diffusion
or active transport
PAC, 1992, 64, 143
(Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992))
on page 159
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook