NEW INSIGHTS INTO THE PHASE-BEHAVIOR OF LIPOPOLYMER MONOLAYERS AT THEAIR WATER INTERFACE - IRRAS STUDY OF A POLYOXAZOLINE LIPOPOLYMER/

Lipopolymers are lipids with a polymer chain covalently attached to th e lipid. We studied the infrared reflection absorption behavior as a f unction of molecular area of Langmuir monolayers of an ether lipopolym er, DC(18)Gly-M-35 (35 monomer units). A plateau region was observed i n the monolayer isotherm. Within this region the CH2 asymmetric and sy mmetric stretching mode absorptions shifted toward lower absorption fr equencies (6 and 4 cm(-1), respectively). This indicates that the plat eau is accompanied by strong local ordering in the lipopolymer, which contradicts previous suggestions that the plateau correlates with a mu shroom-brush transition in the polymer.