Structure, having lateral dimensions much greater than its thickness,
through which transfer may occur under a variety of driving forces.
PAC, 1996, 68, 1479
(Terminology for membranes and membrane processes (IUPAC Recommendations 1996))
on page 1482
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. doi:10.1351/goldbook