Multiscale tracking of emulsion dynamics by aggregation-induced emission.

The inherent multiscale dynamics of materials necessitate synchronous cross-scale investigation, while traditional multiplatform methods always encounter low operational efficiency and analytical uncertainty. Herein, we try to address these limitations by developing a unified monitoring strategy through aggregation-induced emission fluorogens (AIEgens), whose high-contrast photoluminescence (PL) activation triggered by restricted intramolecular motion (RIM) enables multiscale correlation. Molecular-level analysis with AIEgens reveals ultrasensitive PL transitions during emulsion-to-film evolution, quantifying dynamic shifts from movement-free to being restricted by the polymer chain. This molecular responsiveness enables concurrent tracking of particle coalescence and phase transitions at the microscopic level. At the same time, the AIEgen-assisted monitoring platform reveals drying dynamics at the macroscopic scale with high contrast and precision. Through dual feasibility verification in the laboratory and industry, the methodology integrates molecular conformational dynamics, microscale structural rearrangements and macroscale morphological evolution into a single optical framework, which effectively circumvents the platform-dependent analytical limitations. With polymer emulsion as a case study, we provide a generalizable platform for investigating multiscale dynamics in complex material systems, bridging critical gaps between scale-specific observations and holistic process interpretation.