Monolayers of poly(ethylene oxide)-bearing lipids and their mixed mono
layers with dimyristoylphosphatidylcholine at the air-water interface
was investigated using surface pressure measurements. The surface pres
sure-area relationship revealed that the poly(ethylene oxide) moiety l
ength significantly affected the interaction among the lipid molecules
. This study provided a precise picture of the lipid membrane-water in
terface.