Superspreading: Mechanisms and Molecular Design.

Theintriguing ability of certain surfactant molecules to drivethe superspreading of liquids to complete wetting on hydrophobic substratesis central to numerous applications that range from coating flow technologyto enhanced oil recovery. Despite significant experimental efforts,the precise mechanisms underlying superspreading remain unknown todate. Here, we isolate these mechanisms by analyzing coarse-grainedmolecular dynamics simulations of surfactant molecules of varyingmolecular architecture and substrate affinity. We observe that forsuperspreading to occur, two key conditions must be simultaneouslysatisfied: the adsorption of surfactants from the liquid–vaporsurface onto the three-phase contact line augmented by local bilayerformation. Crucially, this must be coordinated with the rapid replenishmentof liquid–vapor and solid–liquid interfaces with surfactantsfrom the interior of the droplet. This article also highlights andexplores the differences between superspreading and conventional surfactants,paving the way for the design of molecular architectures tailoredspecifically for applications that rely on the control of wetting. [ABSTRACT FROM AUTHOR]