Wu Lianfeng, Jiang Qin, Lu Haifeng, Feng Shengyu
Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
Polymers (Basel). 2021 Sep 9;13(18):3046. doi: 10.3390/polym13183046.
Tetraphenylethylene (TPE), a typical luminogen with aggregation-induced emission (AIE) features, has been widely used to prepare AIE fluorescent materials. In this study, TPE-functionalized polydimethylsiloxane (n-TPE-AP-PDMS) was successfully synthesized by attaching TPE to polydimethylsiloxane via aza-Michael addition. The introduction of polydimethylsiloxane to TPE had no obvious effect on photophysical properties. Intriguingly, n-TPE-AP-PDMS exhibited two opposite fluorescence emission behaviors in different systems: aggregation-induced quenching (ACQ) behavior in a tetrahydrofuran/water mixture and typical AIE phenomenon in a tetrahydrofuran/hexane mixture. This unexpected transition from ACQ to AIE can be attributed to a twisted intramolecular charge-transfer effect and flexible aminopropyl polydimethylsiloxane. n-TPE-AP-PDMS was further used as a fluorescent probe to detect nitrobenzene and it showed high quenching efficiency. Moreover, the n-TPE-AP-PDMS film showed high reversibility so that the quenching efficiency remained constant after five cycles. This work can provide a deeper understanding of AIE behavior and guidance to develop a new AIE polymer for chemosensors with high performance.
四苯乙烯（TPE）是一种具有聚集诱导发光（AIE）特性的典型发光体，已被广泛用于制备AIE荧光材料。在本研究中，通过氮杂迈克尔加成反应将TPE连接到聚二甲基硅氧烷上，成功合成了TPE功能化的聚二甲基硅氧烷（n-TPE-AP-PDMS）。将聚二甲基硅氧烷引入TPE对其光物理性质没有明显影响。有趣的是，n-TPE-AP-PDMS在不同体系中表现出两种相反的荧光发射行为：在四氢呋喃/水混合物中表现出聚集诱导猝灭（ACQ）行为，在四氢呋喃/己烷混合物中表现出典型的AIE现象。这种从ACQ到AIE的意外转变可归因于分子内扭转电荷转移效应和柔性氨丙基聚二甲基硅氧烷。n-TPE-AP-PDMS进一步用作荧光探针检测硝基苯，表现出高猝灭效率。此外，n-TPE-AP-PDMS薄膜显示出高可逆性，在五个循环后猝灭效率保持不变。这项工作可以为深入理解AIE行为提供帮助，并为开发用于高性能化学传感器的新型AIE聚合物提供指导。
