DMABN在表面活性剂胶束水溶液中的荧光性质

研究了对二甲氨基苯甲腈(DMABN)在各种胶束水溶液中的荧光光谱性质, 发现不同胶束栅栏层区域的不同性质影响了探针的分子内扭转电荷转移(TICT)特性. 对离子型胶束, 头基电场是主要影响因素, 促进了DMABN分子TICT态的形成, 反离子解离度琢越大, 胶束溶液中的Ia/Ib越强. 在非离子表面活性剂胶束中, 聚氧乙烯链环外壳包裹的大量水使其氢键影响明显, 而很短的聚氧乙烯链还可能带来端基氢的氢键作用. 从DMABN的光物理特性看, 欲将胶束作为分散载体利用其TICT态特性, 选择反离子解离度较大的阴离子胶束(例如SDS或SDSO)较好.

Fluorescence Properties of DMABN in Aqueous Micellar Solutions of Surfactants

Fluorescence spectroscopic properties of p-N,N-dimethylaminobenzonitrile (DMABN) in various kinds of surfactant micellar solutions were investigated. The results showed that the characteristics of the palisade layers of different surfactant micelles affected the twisted intramolecular charge transfer (TICT) properties of DMABN. In the ionic micellar solution, the electric field of the charged head-groups in the palisade layer was found to be a main affecting factor that promoting the formation of TICT state. The larger of the counterion dissociation degree, the stronger of Ia/Ib in the micellar solution. In the nonionic micellar solution, the effect of hydrogen bonding became distinct due to a large amount of water wrapped in the shell of the poly(ethylene oxide) (PEO) chains. Besides, the terminal hydroxyl groups of the short PEO chains were also able to hydrogen-bond with DMABN. In the view of photo-physics of DMABN, the anionic micelles with large dissociation degree of the counterions were suitable to as DMABN dispersed carriers for their TICT properties, for example, SDS or SDSO.