Abstract: The pH dependence of ultraviolet absorption spectra of an aqueous bilayer membrane composed of single-chain ammonium amphiphile containing a Schiff base, has been studied at 10 and 35 ℃, which are below and above the liquid crystalline to gel phase transition (T_c=32 ℃) of the neutral solution, respectively. At 10 ℃, increasing acidity of the solution facilitates the formation of H-aggregate. At 10 ℃, the H-aggregate increases with the decrease of pH value in the range of pH 13.0-10.0. Further increase of acididy leads to the protonation of the Schiff base and thus partially disintegrates the aggregate.

Key words: Schiff base, Synthetic bilayer membrane, Aggregation, Electronic spectra