  Concentric microtubes of $\beta$-cyclodextrin and SDS grow from the outside
in and melt from the inside out, we observe using in situ small angle X-ray
scattering. We find that the conformation of the crystalline bilayer affects
the saturation concentration, providing an example of a phenomenon we call
conformational freezing point depression. We propose a model based on freezing
point depression, well known from undergraduate physics, and use it to explain
the energetics of this hierarchical system, and giving access to material
properties without free parameters.
