Aggregate Science: Much to Explore in the Meso World

constituents as there is a general belief that the parts govern the properties of the whole.1, 2 In this regard, a macro-substance can be reduced to its micro-components, namely ?molecules,?which are the smallest units that theoretically retain the chemical property of a substance. On the other hand, when scientists attempt to create a complex system, it is natural to construct an architecture from its building blocks using a ?bottom-up?approach. Thus, to achieve a substance with the desired properties, there seems to be no doubt of the necessity to design molecules with Researchers face challenges and opportunities in assembling microscopic molecules into macroscopic substances, during which original properties may disappear and new properties may emerge. To understand the science in the middle, studies on mesoscopic aggregates are needed. Research on aggregation-induced emission (AIE) is an ideal entry point for scientists to explore and unravel the mysteries of the meso world, because AIE is a typical phenomenon showing a non-linear property change from molecules to aggregates. AIE luminogens often show no emission in solutions at the molecular level but become brightly emissive when they form mesoscopic aggregates. Aggregation processes generally involve the interplay of competitive or cooperative effects, and new structures, properties, and functions usually appear and diversify in aggregates. In this perspective, four effects, including antagonism, synergism, emergence, and divergence, are abstracted out and instanced by different AIE systems to develop aggregate science and stimulate new ideas from a broad readership.

Automated summary

As scientists assemble microscopic molecules into macroscopic substances, new properties may emerge while original properties may disappear. Studying mesoscopic aggregates can help us better understand these processes.