Guest-driven inflation of self-assembled nanofibers through hollow channel formation

Abstract

The highlight of self-assembly is the reversibility of various types of noncovalent interactions which leads to construct smart nanostructures with switchable pores. Here, we report the spontaneous formation of inflatable nanofibers through the formation of hollow internal channels triggered by guest encapsulation. The molecules that form this unique nanofibers consist of a bent-shaped aromatic segment connected by a m-pyridine unit and a hydrophilic dendron at its apex. The aromatic segments self-assemble into paired dimers which stack on top of one another to form thin nanofibers with pyridine-functionalized aromatic cores. Notably, the nanofibers reversibly inflate into helical tubules through the formation of hollow cavities triggered by p-phenylphenol, a hydrogen-bonding guest. The reversible inflation of the nanofibers arises from the packing rearrangements in the aromatic cores from transoid dimers to cisoid macrocycles driven by the reversible hydrogen-bonding interactions between the pyridine units of the aromatic cores and the p-phenylphenol guest molecules.