Regulating Droplet Dynamics via Wormlike Micelle Networks: From Splash Suppression to Precise Confined Spreading

The high‐speed impact of droplets is fundamental to frontier applications ranging from high‐resolution inkjet printing to precision agriculture. However, simultaneously suppressing stochastic splashing and achieving controllable, uniform spreading on hydrophilic surfaces remains a formidable challenge. Herein, we report a strategy to modulate droplet dynamics, which triggers a structural transition in anionic surfactant (SDS) aggregates via quaternary ammonium cationic induction (CT 1 , CT 4 ). This transition yields a sophisticated internal wormlike micelle (WLM) network that facilitates splash‐free, spatially confined deposition. As a proof of concept, we demonstrate the dual‐regulatory role of the WLM network during high‐speed impact on cotton fabrics. Specifically, the synergistic interaction between CT 4 ‐SDS aggregates and the ionic bonding with the cellulose backbone effectively inhibits excessive spreading during the initial wetting phase. Furthermore, the entanglement of the WLM network with the hierarchical micro/nano‐structures of cellulose fibers generates a powerful interfacial mechanical pinning effect. This effect immobilizes the three‐phase contact line and constructs a spatial barrier at the spreading front. As a result, a stabilized liquid film and uniform circular deposition are ensured. Overall, this study provides a novel mechanistic pathway for steering droplet impact kinetics and offers critical insights into the design of complex fluids for high‐performance functional coating and deposition. As displayed in Graphical image.tif, a molecular‐design strategy precisely tailors high‐speed droplet dynamics through programmed surfactant co‐assembly. The structural transition into an entangled wormlike micelle network completely suppresses stochastic splashing on fibrous substrates. This internal architecture drives rapid interfacial activity and powerful mechanical pinning, unlocking a universal paradigm for high‐precision fluid patterning and deposition.