Observation of microscopic patterning at the air water interface by mixtures of amphiphilic cyclodextrins: a compression isotherm and Brewster angle microscopy study

Mixed monolayers of per-6-ammonium-per-6-deoxy-per-O-2, O-3-hexyl-beta-cycl odextrin (1) and per-O-2, O-3-hexanoyl-beta-cyclodextrin (2) were studied a t the air/water interface by Langmuir balance techniques and Brewster angle microscopy. The mixed monolayers show non-ideal mixing with formation of a 3:2 complex between 1 and 2. Brewster angle microscopy showed the formatio n of microscopic patterning at the interface by the complex and that the sp aces within the two-dimensional cage structures formed are occupied by exce ss of 2 which can undergo phase changes within the cage structures. Copyrig ht (C) 1999 John Wiley & Sons, Ltd.