A. Pinazo et al., SURFACE-PROPERTIES OF AQUEOUS SYSTEMS OF NEW NONIONIC DOUBLE-CHAIN SURFACTANTS AND THEIR MIXTURES WITH DILAUROYLPHOSPHATIDYLCHOLINE, Colloids and surfaces. A, Physicochemical and engineering aspects, 126(1), 1997, pp. 49-58
Three new double-chain nonionic surfactants with the same chain length
as dilauroylphosphatidylcholine (DLPC) have been synthesized with pol
ar groups based on lysine. They are monodisperse (NNepsilon)-N-alpha d
ilauroyl-lysine methyl diethyleneglycolamide (1111KO2 or KO2) and its
analogs with 4 or 6 ethylene glycol units (KO4 and KO6, respectively).
The equilibrium and dynamic surface tensions of 0.1 wt.% dispersions
of these compounds were studied at 37 and 25 degrees C, and were compa
red with those of DLPC and DLPC-KO2 (or KO4 or KO6) mixtures. The spre
ad monolayer pressure-area isotherms were also determined. The equilib
rium surface tensions of KO2 (or KO4, or KO6) are higher than those of
DLPC. The DLPC-KO2 (or KO4 or KO6) mixtures have equilibrium and dyna
mic tension behavior closer to that of DLPC alone. The lack of a zwitt
erionic polar group produces a big difference in their surface activit
y, in part because of differences in their phase behavior. (C) 1997 El
sevier Science B.V.