Study on Fluorescence Spectroscopy Characteristics of Isopropanol-Water Solution

The fluorescence and polarization spectra of isopropanol-water solution excited by ultraviolet light and linearly polarized light are studied experimentally. The fluorescence spectral characteristics and emission mechanism are discussed. The molecular clusters information in different concentration and polarization property are analyzed. It is found that the isopropanol-water solution obtains the type η → π electron transition, and emits fluorescence with optimal fluorescence peak of 284 nm and 331 nm excited by ultraviolet light with 220 nm and 232 nm wavelengths, respectively. When isopropanol-water solution with different volume percentages are induced by exciting light with same wavelength, the fluorescence spectra of isopropanol-water solution change with volume percentages. Cluster molecules with chain or cyclic type orientation are formed in isopropanol-water solution by the action of hydrogen bond. The fluorescence of isopropanol-water solution is partially polarized light with certain molecular orientation, whose polarization degree and anisotropy degree are 0.542 and 0.703, respectively. The research can contribute to the physicochemical property study of isopropanol-water solution and molecular cluster structures.