Exclusion of fluid lipid during compression of monolayers of mixtures of dipalmitoylphosphatidylcholine with some other phosphatidylcholines.

Monolayers composed of dipalmitoylphosphatidylcholine and one of four fluid phosphatidylcholines have been studied for their ability to attain low minimum surface tension during compression at two different speeds. The minimum surface tension depended on the compression rate and the proportions of the fluid and rigid lipid in the monolayer. The type of fluid lipid used in the monolayer also affected the minimum surface tension.