Study on J-aggregate formation of a long-chain merocyanine in the mixed LB films and their optical behavior

摘要

We have studied the J-aggregates in binary mixed LB films of the amphiphilic merocyanine dye (abbr. 5-ClMc) with cadmium arachidate (AA) (5-ClMc:AA = 1:2) and in ternary system with octadecane (OD) (5-ClMc:AA:OD = 1:1:1). The absorption spectra of the mixed dye LB films were fitted by the Lorentzian. As a result, the ternary and the binary systems were consisted of five and seven components, respectively. By using the extended dipole model, the energy shift of each component was in good agreement with the corresponding aggregation number N = 4～14 at the slip angle α = 26 °C. Furthermore, the J-aggregate in the mixed dye LB films was observed by using the scanning near-field optical microscopy (SNOM). Round domains with diameter of 250nm were observed in the binary system, while in the ternary system smaller bright parts appeared.