A study shows that diblock copolymers made from peptide analogs called peptoids can stack together in a novel way to form crystalline nanotubes. Ronald N. Zuckermann of Lawrence Berkeley National Laboratory and coworkers created the new class of nanotubes by synthesizing diblock copolymers containing same-sized blocks of hydrophilic (ethyleneoxy side-chain) and hydrophobic (decyl side-chain) poly(N-substituted glycines). The peptoid chains form rings that stack vertically, with the hydrophilic and hydrophobic blocks aligning with one another, by a not-yet-understood mechanism, to form nanotubes with amphiphilic interior and exterior surfaces (Proc. Natl. Acad. Sci. USA 2016, DOI: 10.1073/pnas.1517169113). Self-assembling nanotubes have been prepared before by mechanisms involving hydrogen bonding, electrostatic, or π-π interactions. But the new ones do not form via any of those mechanisms. The researchers hope to learn how they do form, as well as determine their atomic-resolution structure, cross-link th...