关键词: 单层磷脂;表面平衡现象;空气;水;接触面, state equation

Abstract: A surface equation of state, applicable to liquid-expanded (LE) monolayers, was derived by
analyzing the Helmholtz free energy of the LE monolayers. Based on this equation, a general
equation was obtained to describe all states of single-component phospholipid monolayers
during comprassion. To verify the applicability of the equation, π-A isotherms of 1,2-
dipalmitoylphosphatidylcholine (DPPC), 1,2-dipalmitoylphosphatidylglycerol (DPPG), and 1,2
-dimyristoyphosphatildylcholine (DMPC) were measured. The comparison between model and
experimental values indicates that the equation can describe the behavior of pure
phospholipid monolayers.

Key words: π-A isotherms, 1, 2-dimyristoyphosphatildylcholine, 1, 2-dipalmitoylphosphatidylcholine, 1