Spectroscopic properties of mixed Langmuir-Blodgett films of rhodamine dyes and poly(N,N-diallyl-N-octadecylamine-alt-maleic acid)

Langmuir-Blodgett (LB) films of poly(N,N-diallyl-N-octadecylamine-alt-maleic acid) as well as mixed films consisting of polyampholyte and two amphiphilic fluorophores - alkyl substituted rhodamine dyes - were prepared and investigated. The pi-A isotherm of the polyampholyte at air-water interface is typical for monolayer in the liquid state. Mixed monolayers of polyampholyte and rhodamine amphiphiles show improved packing of the hydrophobic chains. Absorption and fluorescence spectroscopic studies of the mixed LB films reveal the aggregation of dyes in the densely packed multilayer films.