Hierarchical Superspreading Structures for Ultrafast Droplet Transport and Bubble Management

Integrated with multi-scale structure and surface chemical composition, superspreading micro-nano porous materials have made breakthroughs in the fields of bubble adhesion resistance and fluid transport. The pressing problems associated with superspreading materials are their inherent defects such as system compatibility issues, capillary limitation, or loss of modified hydrophilic groups. Here, leveraging the spontaneous agglomeration of inorganic particles and the optimization of the micro-nano structure, the ingeniously designed SiC─SiO₂-based superspreading micro-nano structures have excellent droplet spreading (6.5 ms) and extremely high capillary performance parameter of K/R_eff = 2.08, thus forming a scalable, efficient and cost-effective structure. The combination of superhydrophilicity (water contact angle, WCA = 0°) and capillary effect can significantly eliminate the local pinning effect, promote the advancement of the three-phase contact line (TCL), and form a stable and efficient superspreading water flow. Furthermore, the superspreading micro-nano structures exhibit the fastest evolution of bubble growth with an extremely fast growth-desorption cycle (<20 ms) and the smallest bubble stripping size (139.9 µm). The system provides insights into the experimental and theoretical applications of two-phase (liquid, vapor) flow, and can be further extended to other more complex liquid transport functional systems for the development of intelligent superspreading structural materials.