Wrinkling Nanoparticle Sheets

Governed by Microscopic Structure and Fold Kinetics

The Lin, and Lee groups from the University of Chicago MRSEC collaborated with Coppersmith (University of Wisconsin) to characterize how a thin sheet of self-assembled nanoparticles at the air-liquid interface buckles when compressed. Uniaxial compression of the monolayer results in the appearance of lines that have been shown to be regions oftrilayer. These lines exhibit complex patterns that depend on the extent of compression. They show that these patterns can be understood in terms of an equilibrium statistical mechanical theory, originally developed in the context of commensurate–incommensurate transitions in krypton monolayers adsorbed on graphite, in which there is an energy cost to line deformations and to line intersections.Wrinkling from monolayer to trilayer nanoparticle sheet governed by microscopic structure. The image depicts the aggregate evolution of wrinkle pattern controlled by kinetics of fold development. 

Incommensurate phases of a supported nanoparticle film subjected to uniaxial compression

Y. Chua, B. Leahy, M. Zhang, S. You, K. Y. C. Lee, S. N. Coppersmith, and B.Lin,Proc. Nat. Acad. of Sciences,110, 824 (2012). doi: 10.1073/pnas.1101630108