Spreading properties of dimyristoyl phosphatidylcholine at the air/water interface.
The spreading behavior of bulk lipid crystals and lipid dispersed in water has been investigated for dimyristoyl phosphatidylcholine at the air/water interface. The stable surface pressures reached with dispersed lipid were found to increase with lipid concentration up to a concentration of approximately 1.2 mg ml-1 where the spreading pressure approached 45 mN m-1, the value for excess lipid crystals placed on the surface (at 30.5 degrees C). These low surface pressures obtained with dispersions are attributed to the existence of 'pre-equilibria': surface pressures that appear steady because of the extremely slow approach to final equilibrium. Attainment of this pre-equilibrium condition usually takes about 20 h, whereas bulk crystals held at the surface generated a high and steady surface pressure within about 1 h. Hydration of the bulk lipid slows down the spreading rate, but does not affect the final surface pressure.
Department of Chemistry, The University of Queensland, St. Lucia, Australia.
G A
GA
Lawrie
P B
PB
Schneider
B J
BJ
Battersby
G T
GT
Barnes
H K
HK
Cammenga
D000388:Air; D004134:Dimyristoylphosphatidylcholine / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D009226:Myristates / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000378:metabolism*; D013499:Surface Properties; D014867:Water / Q000378:metabolism
D008051:Lipid Bilayers; D008081:Liposomes; D009226:Myristates; D010713:Phosphatidylcholines; D014867:Water; D004134:Dimyristoylphosphatidylcholine