激光诱导时间分辨光谱技术研究胶束体系中荧蒽的室温燐光行为

Study on Room Temperature Phosphorescence Behavior of Fluoranthene by Laser Induced Time Resolved Technique

在胶束体系中 光衰减符合一级指数衰减公式Ｐｔ＝Ｐｏｅ－ｔ／ｒ，作者以激光诱导时间分辨光谱技术测量了ＳＤＳ胶束中荧蒽的燐光寿命和瞬时燐光强度产。值。提出Ｐｏ可定性表示重原子效应对燐光体经Ｓ１－Ｔ１系间跃迁几率的影响．而ｔ值表示三线态失活几率大小，即反映了胶束对燐光体的保护作用。作者详细研究了ＴＩＮＯ３用量、ＳＤＳ用量、ｐＨ值、Ｎａ２ＳＯ３用量对上述参数的影响，以期说明胶束增稳室温燐光法中影响燐光行为的各种因素的作用本质。

Room temperature phosphorescence (RTP) decay generally follows a first order exponential law Pt=Poe-t/r in a micelle system. The transient phosphorescence intensity Po (pre-exponential factor) and phosphorescence lifetime r could be used to qualitatively indicate the probability of (S1 -T1 )intersystem crossing (ISC) andradiationless deactivation (T1,S0) of the phosphors, respecttively, in micelle systemr. These two factors indirectly reflect the inducing effect of heavy atom on the probability of ISC of phosphor and the proservation of micelle to phosphor. In this paper, P0, and t of fluoranthene were measured by a laser induced time resolved technique. The effects of the concentration of heavy atom species,surfactant SDS as well as pH on the above parameters were studied. The experiments showed that the amount of T1+ ions associated with micelle surface governed the probability of (S1 T1) intersystem crossing,which can beindirectly studied by change of P0. The Na2SO3 concentration and pH mainly affect deoxygenation efficiency, which induces changes of t because of quenching of uneliminated oxygen. Since fluoranthene possesses longer phosphorescence lifetime, the use of it as a probe can more sensitively reflect the changes of environment. Meanwhile, the long lifetime makes it possible to obtain the pre-exponential factor.