The influence of counter ions on the morphology of cyanine dye aggregates at the air/water interface

In a cyanine dye LB film, the J-aggregates of the dye molecules form domain structure. The shape and size of this structure are largely influenced by the conditions of film fabrication. We made a through investigation about the effects of counter anions of the dye molecules and ions as additives in the subphase on the domain structure in dye monolayers at the air/water interfaces and in LB films by using a fluorescence microscope. We found the conditions under which we can promote or prevent the growth of the domains, and discussed the influence of anions on pi-A isotherm.