含罗丹明B的纳米复合介孔薄膜的制备和性能(英文)

Preparation and properties of nano-composite mesostructured thin films containing rhodamine B

采用溶胶-凝胶技术、蒸发诱导自组装法,通过酸/酸二步法控制实验条件,实验中采用表面活性剂十六烷基三甲基溴化氨(CTAB)为模板剂,正硅酸乙酯为硅源、罗丹明B、以及二次去离子水,盐酸为催化剂等原料制备前驱体溶胶。通过简单提拉迅速蒸发溶剂制备介孔薄膜,对介孔薄膜进行了X射线衍射、透射电子显微镜表征,观察了薄膜样品的吸收光谱和荧光光谱。含罗丹明B膜的吸收光谱表明主峰是RhB单体的吸收和微弱吸收的次峰是RhB形成的二聚体的吸收。而在荧光光谱中只有一个发射谱带,这是RhB单体的最低激发能级到基态能级的跃迁.含罗丹明B的纳米复合介孔薄膜中,随着RhB浓度的增大,荧光峰位发生红移,这可以说明激发态分子的偶极矩减小。

Nano- composite mesostructured thin films containing rhodamine B have been prepared. A precursor sol containing tetraethoxysilane, ethanol, surfactant eetyhrimethylammonium bromide （ CTAB）, water, rhodamine B and acid catalyst was prepared by sol - gel, the control being suitable response condition. Depositing the precursor sol on a substrate wherein evaporation of solvent and water causes the formation of mesostructured films on the substrate surface by evaporation - induced self - assembly process. The mesoporous film was characterized by XRD and TEM. The absorption and fluorescence spectra of the films have been observed. The UV - visible absorption spectra of the films incorporated with rhodamine B show that the main absorption band of rhodamine B - doped films can be attributed to the rhodamine B monomers, and only a very weak absorption band of the dimer can be observed. The single emission band in fluorescence spectra of rhodamine B - doped films can be attributed to transitions from the lowest - lying level of the first excited electronic state to the electronic ground state of rhodamine B monomers. The red shifts in the peak of the luminescence spectra with increasing rhodamine B - content in the films which may be interpreted as reflecting a decrease in the dipole moment of the excited molecule.