Emission Modulation of Poly(vinyl acetate)-Tetrabutylphosphonium Tetrafluoroborate Hybrid Film Doped with 4-[Bis(4-methylphenyl)amino]-benzaldehyde

Abstract

A hybrid film of poly(vinyl acetate) and tetrabutylphosphonium tetrafluoroborate together with 4-[bis(4-methylphenyl)amino]benzaldehyde as a fluorescent dopant was fabricated. It was found that the film exhibited thermally reversible phase-separation and dissolution transitions and that both homogeneous and phase-separated states could be obtained at room temperature by appropriate thermal treatments. In addition, emission modulation of the film was achieved by using the phase-separation-dissolution transitions. Fluorescence properties including fluorescence life times and quantum yields in homogeneous film seemed to be unchanged by phase separation, suggesting that no significant change in the surrounding environment of the dopant molecules took place by phase-separationdissolution cycles. Therefore, the emission modulation observed here was suggested to be due to mainly the change in the light-scattering effect caused by phase transitions.