Harnessing Surface Wrinkling Instability for Visualizing Dynamic Chemistry in Polymer Networks

Studying dynamic chemical behaviors is fundamental to understanding and regulating the dynamic responses and functions of polymer materials. However, real-time, intuitive, and selective visualization of these molecular processes─particularly when multiple dynamic motifs coexist─remains a major challenge. Herein, we introduce surface wrinkles as a visualization platform that directly translates dynamic chemical behaviors in polymers into observable macroscopic morphological changes. Using a dual-cross-linked polymer network (DCN) containing quadruple hydrogen bonds and mechanical bonds as a model system, we fabricate stable wrinkles via modulus mismatch in a bilayer architecture. In situ microscopy reveals that acid-triggered dissociation of quadruple hydrogen bonds causes rapid wrinkle erasure due to network disruption, whereas base-induced rotaxane sliding leads to gradual wrinkle erasure owing to network relaxation, reflecting their distinct dynamic mechanisms and time scales. Rheological analyses on single-cross-linked model networks corroborate these macroscopic observations at the molecular level. Moreover, by programming wrinkle patterns with "write-hide-read" functionality, we achieve macroscopic visualization and differentiation of microscopic dynamic processes. This work establishes surface wrinkling as a powerful and intuitive platform for real-time monitoring of dynamic chemistry and provides valuable insights for designing functional polymer materials with tunable macroscopic properties.