I . Oriented Layers of Tripalmitin

The structure of tripalmitin multilayers prepared by the L a n g m u i r B l o d g e t t technique has been investigated within room temperature and 62 °C using infrared internal reflection spectroscopy (ATR) . It was found that the bilayer structure exhibits crystalline features with pseudo hexagonal structure. The methylene groups of the hydrocarbon chains are in the all-trans-zig-zag conformation, oriented perpendicularly to the germanium internal reflection plate. Increasing temperature produces at first a continuous conformational change in the glycerol part of the molecule. This process is extended over nearly 10° and followed by sudden melting (disordering) of the hydrocarbon chains within 1°. In comparison microcrystalline tripalmitin shows an identical infrared spectrum and analogous behaviour at increased temperatures. This indicates that the bilayer structure (head-head, tail-tail) also exicts in the crystal.