Molecular positional order in a dipalmitoylphosphatidic acid Langmuir–Blodgett monolayer by atomic force microscopy

Langmuir–Blodgett monolayers of dipalmitoylphosphatidic acid were studied by using atomic force microscopy on the large- and nano-scale. A molecularly resolved image was achieved at high surface pressure. The monolayer shows a dramatic long-range orientational and positional ordering of molecular organization of aliphatic tails. The ordered molecular arrangement of aliphatic tails may result from the strong intermolecular hydrogen bonding interactions between adjacent phosphate groups in the polar region.