Fluorescence Enhancement in a Polyurethane Containing an Organic Dye.

摘要

Transparent polyurethane sheets have been prepared containing a dispersed or covalently bonded organic dye. The fluorescent dyes are 2-diphenylacetyl-1,3-indanedione-1-p-dimethylaminobenzaldazine or the p-dihydroxyethylamino-benzaldazine analog, which can be called DIPAIN derivatives. Changes in the fluorescence of the dyes have been studied in the presence of methyl benzilate and several nonvolatile aliphatic alcohols. When methyl benzilate is added during polymerization, fluorescence in both dye-containing sheets increases, but the effect is greater for the sheet containing the covalently bonded dye. When solution of methyl benzilate is dropped on the surfaces of the dye-containing sheets, the effect is greater for the dispersed dye. The dimethyl dye blooms to the surface of the polyurethane sheet and can be wiped off as a fine orange powder. Decyl alcohol shows an enhancement effect when spotted together with the dimethyl dye on a silica gel TLC plate. Fluorescence enhancement is also observed when a polyurethane sheet containing dimethyl dye is placed in contact with decyl alcohol vapor. The nature of the interaction can include the aromatic ring systems of the dye and methyl benzilate, and also the interaction of the dye with decyl alcohol through hydrogen bonding.