Effect of bilayer number on the photoluminescent property of TPE-based self-assembled film  

作　　者：CHEN DiDi FENG Xiao GU ShangZhi TONG Bin SHI JianBing ZHI JunGe DONG YuPing 

机构地区：[1]College of Materials Science and Engineering,Beijing Institute of Technology [2]College of Chemistry,Beijing Institute of Technology

出　　处：《Chinese Science Bulletin》2013年第22期2728-2732,共5页

基　　金：supported by the National Natural Science Foundation of China(51073026,51061160500,20944004,21074011,21004004);the National Basic Research Program of China(2013CB834704);the Specialized Research Fund for the Doctoral Program of Higher Education of China(20091101110031)

摘　　要：Tetraphenylethylene (TPE) derivatives have been proved to be typical aggregation-induced emission (AIE) luminogens when they were aggregated in the free three-dimensional space. In order to reveal the effect of the dimensional degree on AIE property of TPEs, we utilized tetra(4-hydroxyphenyl)ethylene (TPE-4OH) and 1,4-benzenediamine diazonium salt (BD) to fabricate the ultrathin films (TPE-4OH/BD LBL SA film) through layer-by-layer self-assembled technique. The interaction between TPE-4OH and BD in the films was converted from electrostatic force and hydrogen-bond to covalent bonds through photodecomposition of diazonium groups under UV irradiation. Fluorescence emission spectroscopy, UV-Vis absorption spectroscopy and atomic force microscope were carried out to evaluate the relationship between bilayer number and photoluminescence of the TPE-based self-assembled films. The experimental results showed that the TPE-based film with three bilayers only displayed AIE character, whereas the fluorescence of the film became randomly changed if the bilayer number was above three. It is supposed that the fluorescence property of the TPE-4OH/BD LBL SA film with limited molecular length in z-axis and infinite aggregation space in x-and y-axis is dominated by two competitive effects, one is the partial restriction of intramolecular rotation through short inter-molecular interactions in cross-linked structure of TPE-4OH/BD, and the other is deactivation of its excited state through unrestricted intramolecular rotations or π-π interactions.Tetraphenylethylene （TPE） derivatives have been proved to be typical aggregation-induced emission （AIE） luminogens when they were aggregated in the free three-dimensional space. In order to reveal the effect of the dimensional degree on AIE property of TPEs, we utilized tetra（4-hydroxyphenyl）ethylene （TPE-4OH） and 1,4-benzenediamine diazonium salt （BD） to fabricate the ultra- thin fdms （TPE-4OH/BD LBL SA film） through layer-by-layer self-assembled technique. The interaction between TPE-4OH and BD in the films was converted from electrostatic force and hydrogen-bond to covalent bonds through photodecomposition of dia- zonium groups under UV irradiation. Fluorescence emission spectroscopy, UV-Vis absorption spectroscopy and atomic force microscope were carried out to evaluate the relationship between bilayer number and photoluminescence of the TPE-based self-assembled films. The experimental results showed that the TPE-based film with three bilayers only displayed AIE character, whereas the fluorescence of the film became randomly changed if the bilayer number was above three. It is supposed that the fluorescence property of the TPE-4OH/BD LBL SA film with limited molecular length in z-axis and infinite aggregation space in x- and y-axis is dominated by two competitive effects, one is the partial restriction of intramolecular rotation through short inter- molecular interactions in cross-linked structure of TPE-4OH/BD, and the other is deactivation of its excited state through unre- stricted intramolecular rotations or π-π interactions.

关 键 词：自组装膜 发光性能 分子间相互作用 热塑性弹性体 荧光发射光谱 紫外线照射 层数 原子力显微镜 

分 类 号：TB383.2[一般工业技术—材料科学与工程]