Molecular architecture engineering of Oligo(dimethylsiloxane) functionalized giant surfactants for self-assembled Sub-10 nm nanostructures

Giant surfactants incorporating polyhedral oligomeric silsesquioxane (POSS) cages and tailorable polystyrene (PS) tails, were developed to achieve sub-10 nm nanostructures through molecular self-assembly. We have designed a series of giant surfactants by functionalizing POSS cages with oligo(dimethylsiloxane) (oDMS) ligands. Molecular architectures, including oDMS ligand lengths, the number of PS chain(s) and molecular weights were systematically synthesized to precisely control critical dimensions of self-assembled nanostructures. With changing those structural parameters, a phase transition from lamellar to hexagonal columnar structures was identified. Notably, the hexagonal columnar structures are practically important in direct self-assembly techniques. Furthermore, highly ordered sub-10 nm line patterns were successfully fabricated via spin-coating and reactive ion etching, providing molecular design strategies for advanced nanolithography. This study not only expands the structural design of giant surfactants but also demonstrates their promising applications in nanomanufacturing.