9,10-Diphenylanthracene immobilized in mesostructured silica materials with a highly efficient deep-blue fluorescent property

Abstract

The fluorescent solid material, which emits highly efficient deep-blue light, was successfully fabricated by stabilized 9,10-diphenylanthracene (DPA) molecules in mesostructured silica material (MSM) (referred to as DPA-MSM). The DPA molecules are favorably introduced into the hydrophobic domain of a self-assembled amphiphilic triblock copolymer (poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), Pluronic P123) template through a one-pot synthetic route based on the van der Waals interaction. Powder X-ray diffraction patterns show that the unit-cell parameter of DPA-MSM was 1.2nm larger than that of pure MSM, along with the well-ordered hexagonal structure. The photophysical properties of DPA-MSM have been studied and compared with those of DPA in solution (0.15mM) and powdered states, respectively. Both absorption and emission maxima of the immobilized DPA show a remarkable hypsochromic shift as compared with those of pure DPA powder. In addition, we have observed distinct spectral features in the DPA-MSM, which resemble those of DPA dissolved in cyclohexane, indicating that the immobilized DPA is molecularly separated by the interactions with the poly(propylene glycol) part in P123. The fluorescence decay behavior showed that DPA-MSM has a longer lifetime because the intramolecular motions of DPA are strongly restricted by the confined environment within the pore channel of rigid MSM. These results also show that the immobilized DPA has a higher fluorescence quantum yield than did DPA in dissolved or powdered states. The fabricated blue LED chip with DPA-MSM exhibited outstanding deep-blue color with CIE coordinates of (0.15, 0.03). It was found that the incorporation of DPA in MSM provides an efficient blue emitter in the solid-state.