Crystalline Order Propagates Across Thick Layers of Water in Solutions of Supramolecular Nanotubes

Abstract

Abstract3D crystalline order with 1 nm resolution is observed in aqueous solutions of supramolecular nanotubes containing 94 % water, at concentrations as low as 6 wt%. 50 of star‐like organic ions arrange into supramolecular rings which, in turn, stack on top of each other to form long hollow tubes with 15 nm outer diameter. Cryo‐TEM and X‐ray diffraction show that the parallel nanotubes arrange on a perfect hexagonal lattice. Unexpectedly, fiber diffraction on sheared solutions revealed numerous hkl Bragg reflections on several layer lines indicating longitudinal interlock between the tubes and 3D crystalline order with molecular‐scale details transferred across 10 nm thick layers of water. The observed high 3D order is attributed to long‐range attraction between like‐charged tubes and amplified charge modulation by the extremely high intra‐tube correlation length.