Membraneless Organelles‐Inspired Self‐Stratified Coatings for Rapid Interfacial Water Transport

ABSTRACT

Achieving stable self‐stratified coatings without compromising interfacial water transport remains a long‐standing challenge, as existing stratification mechanisms based on surface‐energy differences or polymer incompatibility often introduce internal stresses and require hydrophobic components. Membraneless organelles possess a stratified structure that supports structural robustness and rapid molecular transport. Inspired by these features, we uncover a differential interaction‐driven self‐stratified coating mechanism using tannic acid (TA) and a broad range of binary copolymers. By combining one‐step high‐throughput preparation with machine‐learning‐guided stability prediction, we identify that moderately interacting segments of the copolymers with TA preferentially anchor at the substrate to form a stable inner layer, while weakly interacting segments migrate outward to generate a functional outer layer. Unlike conventional stratification dominated by internal stress accumulation, the largely differential interactions enable sufficient molecular rearrangement during self‐stratification, thereby enhancing coating stability. Moreover, distinct from cell‐membrane‐inspired stratified coatings that rely on hydrophobic barriers, the resulting self‐stratified coatings can be composed entirely of hydrophilic components, enabling rapid interfacial water transport. Consequently, we screened and obtained superhydrophilic coatings that exhibited excellent performance in oil–water separation, antifouling, and anticoagulation. This study establishes a generalizable, interaction‐guided mechanism for self‐stratification and expands the design space of multifunctional and adaptive interfacial coatings.