Hierarchical Self-Assembly of Block Polymeric Foldamers into Membranes with Tunable Pore Sizes

Molecular foldamers are synthetic oligomers and polymers that emulate the structural and functional behaviors of natural biomolecules by spontaneously organizing into well-defined two- and three-dimensional structures. Built from diverse non-natural building blocks, foldamers offer expanded chemical diversity, enhanced stability, and tunable physical properties. In this study, we present foldameric linear block co-polymer that self-assembles into polygons with programmable pore sizes. The foldamer is composed of two alternating helix-forming and flexer blocks. The helix-forming block adopts a rigid helical structure, while the flexer block collapses via hydrophobic interactions, serving as a flexible pivot. Cyclization of each flexer at both ends results in closed polygon formation. We identified three distinct folding regimes (disordered, 2D, and 3D) depending on the lengths of the helix and flexer blocks. Notably, in the 2D regime, the polygons form with high efficiency, and multi-chain systems generate long-range ordered structures that could act as breathable membranes with well-defined pore sizes. This model offers new insights into helix formation from a coarse-grained perspective, improving computational efficiency of helix-forming simulation. Furthermore, the polygon self-assembly suggests promising applications in material science where precise structural control and functional versatility are essential.