title: Shaken, not stirred: collapsing a peptoid monolayer to produce free-floating, stable nanosheets.
abstract: Two-dimensional nanomaterials play a critical role in biology (e.g., lipid bilayers) and electronics (e.g., graphene) but are difficult to directly synthesize with a high level of precision. Peptoid nanosheet bilayers are a versatile synthetic platform for constructing multifunctional, precisely ordered two-dimensional nanostructures. Here we show that nanosheet formation occurs through an unusual monolayer intermediate at the air-water interface. Lateral compression of a self-assembled peptoid monolayer beyond a critical collapse pressure results in the irreversible production of nanosheets. An unusual thermodynamic cycle is employed on a preparative scale, where mechanical energy is used to buckle an intermediate monolayer into a more stable nanosheet. Detailed physical studies of the monolayer-compression mechanism revealed a simple preparative technique to produce nanosheets in 95% overall yield by cyclical monolayer compressions in a rotating closed vial. Compression of monolayers into stable, free-floating products may be a general and preparative approach to access 2D nanomaterials.
authors.affiliation: The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Babak
authors.initials: B
authors.lastname: Sanii
authors.forename: Romas
authors.initials: R
authors.lastname: Kudirka
authors.forename: Andrew
authors.initials: A
authors.lastname: Cho
authors.forename: Neeraja
authors.initials: N
authors.lastname: Venkateswaran
authors.forename: Gloria K
authors.initials: GK
authors.lastname: Olivier
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Olson
authors.forename: Helen
authors.initials: H
authors.lastname: Tran
authors.forename: R Marika
authors.initials: RM
authors.lastname: Harada
authors.forename: Li
authors.initials: L
authors.lastname: Tan
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Zuckermann
mesh_terms: D000388:Air; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D034444:Peptoids / Q000737:chemistry*; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D034444:Peptoids; D014867:Water