AFM-INVESTIGATION OF THE MOLECULAR-STRUCTURE OF FILMS FROM A POLYMERIZABLE 2-CHAIN LIPID

Monolayers of the polymerizable two-chain lipid dimethyl-bis[pentacosa diinoic-oxyethyl] ammonuim bromide were investigated by him balance te chniques and with a combined microfluorescence/atomic force microscope . Images at molecular resolution from both headgroup side up and tail side up films are presented. The superposition of the two lattices def ines a unit cell containing two molecules. The combined microfluoresce nce/atomic force microscope in one instrument allowed us to assign the direction of the polymer backbone relative to the molecular orientati on in the polymerized films. Two clearly distinct surface morphologies were found in the polymeric films when imaged from the tail and from the head side. The first being hat with a highly ordered molecular lat tice and the second showing an ondulated surface topology at lower mag nifications with poor order at molecular dimensions probably caused by a lattice frustration.