title: Structure-determining step in the hierarchical assembly of peptoid nanosheets.
abstract: Organic two-dimensional nanomaterials are of growing importance, yet few general synthetic methods exist to produce them in high yields and to precisely functionalize them. We previously developed an efficient hierarchical supramolecular assembly route to peptoid bilayer nanosheets, where the organization of biomimetic polymer sequences is catalyzed by an air-water interface. Here we determine at which stages of assembly the nanoscale and atomic-scale order appear. We used X-ray scattering, grazing incidence X-ray scattering at the air-water interface, electron diffraction, and a recently developed computational coarse-grained peptoid model to probe the molecular ordering at various stages of assembly. We found that lateral packing and organization of the chains occurs during the formation of a peptoid monolayer, prior to its collapse into a bilayer. Identifying the structure-determining step enables strategies to influence nanosheet order, to predict and optimize production yields, and to further engineer this class of material. More generally, our results provide a guide for using fluid interfaces to catalytically assemble 2D nanomaterials.
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States.
authors.forename: Babak
authors.initials: B
authors.lastname: Sanii
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Haxton
authors.forename: Gloria K
authors.initials: GK
authors.lastname: Olivier
authors.forename: Andrew
authors.initials: A
authors.lastname: Cho
authors.forename: Bastian
authors.initials: B
authors.lastname: Barton
authors.forename: Caroline
authors.initials: C
authors.lastname: Proulx
authors.forename: Stephen
authors.initials: S
authors.lastname: Whitelam
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Zuckermann
mesh_terms: D002384:Catalysis; D008958:Models, Molecular; D049329:Nanostructures; D034444:Peptoids / Q000737:chemistry*; D011487:Protein Conformation; D012542:Scattering, Radiation
chemical_list: D034444:Peptoids
keywords: bioinspired polymers; coarse-grained modeling; interfacial assembly; monolayer compression; protein-mimetic materials; supramolecular assembly; two-dimensional materials