Organization and properties of a novel amphiphilic crown-ether dye in monolayers at the air/water interface

The novel amphiphilic benzodiaza-15-crown-5-styryl dye (BI68) forms stable insoluble monolayers at the air/water interface (collapse pressure 47 mN/m) and on aqueous subphases containing alkali metal or heavy metal salts (collapse pressures in the range of 38–45 mN/m, respectively). The organization of the dye monolayer depends on chromophore association and interactions with salts in the subphase as observed by measuring surface pressure–area and surface potential–area isotherms, reflection spectra and by Brewster angle microscopy observations. Immiscibility was found in two-component monolayers of BI68 and random copolymers of styrene with methacrylic acid and with N-vinylpyrrolidone, respectively.