Special Chemical Engineering Seminar

Efficient luminescent materials hold great promise for high-tech applications in energy, environment, and healthcare, etc. The light emission of conventional luminophores is often weakened or quenched when the molecules are aggregated, which is notoriously known as aggregation-caused quenching (ACQ). Considering that luminophores are commonly used as solid or aggregate, strong solid-state emitters are highly desirable. In 2001, we discovered a kind of propeller-like molecules that showed opposite luminescence behavior to the ACQ effect: the aggregate formation turned on their light emission, changing them from weak fluorogens into strong emitters. We termed this novel phenomenon as aggregation-induced emission (AIE). Through detailed mechanistic study of the photophysical processes, restriction of intramolecular motion (RIM) was identified as the main cause of the AIE effect. Under the guidance of RIM mechanism, we have developed a great number of AIE luminogens (AIEgens) with emission colors covering the entire visible, even extending to UV and near-IR spectral region. We have also explored the intriguing applications of AIEgens in such areas as optoelectronic devices, chemo/biosensing, and biomedical imaging. In this lecture, I will share the excitement in studying this group of wonder molecular aggregates and in exploring their special applications.