| 초록 |
Light-emitting chromophores (LEC) with large Stokes shift have been separated from silica spheres modified the surface with TMSPM. The surface modified silica spheres were soaked into the acetone and stored for 20 days at ambient condition. The absorption peaks of the extracted LEC at 3348, 2869, 2927, 1715, 1453/1377, 1296, and 1120 cm-1 represent C-OH, R-CH3, R2-CH2, -C=O, C-H, C=C-H, and Si-O-Si absorption, respectively. The FTIR absorption peak at 1715 cm-1 representing the ester –C=O stretching vibration for the silica spheres stored for 20 days is increased compared with the before aging the spheres. The UV-visible absorption peaks are at 4.51 eV (275 nm) and 3.91 eV (317 nm). There are two luminescence peaks at 2.51 eV (495 nm) and 2.25 eV (550 nm). The emission at 2.51 eV is dominant peak when the excitation energy is higher than 2.58 eV, and emission at 2.25 eV becomes dominant peak when the excitation energy is lower than 2.58 eV. |
