D. Gidalevitz, O. Y. Mindyuk, M. R. Stetzer, P. A. Heiney, M. L. Kurnaz, D. K. Schwartz, B. M. Ocko, J. P. Mccauley, Jr., and A. B. Smith, III, J.\ Phys.\ Chem.\ B 102, 6688-6691 (1998).
We have used grazing-incidence x-ray diffraction, x-ray reflectivity, and Brewster angle microscopy, to study an amphiphilic azacrown derivative at the air-water interface. The compound stuied has a ring-shaped, flexible core with six alkyl chains attached. As the density is increased, the molecules undergo a phase transition from a face-on structure, with the alkyl tails extending away from the interface, to a thicker edge-on structure, with the tails extending radially away from the core. Concomitant with this rearrangement, the film develops long-range in-plane structural order.