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In situ Mechanical Testing Reveals Periodic Buckle Nucleation and Propagation in Carbon Nanotube Bundles
Author(s) -
Hutchens Shelby B.,
Hall Lee J.,
Greer Julia R.
Publication year - 2010
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201000305
Subject(s) - materials science , buckling , bundle , composite material , nucleation , deformation (meteorology) , context (archaeology) , carbon nanotube , microstructure , dissipation , compression (physics) , buckle , chemical vapor deposition , nanotechnology , thermodynamics , paleontology , physics , biology
Uniaxial compression studies are performed on 50‐µm‐diameter bundles of nominally vertical, intertwined carbon nanotubes grown via chemical vapor deposition from a photolithographically defined catalyst. The inhomogeneous microstructure is examined, demonstrating density and tube orientation gradients, believed to play a role in the unique periodic buckling deformation mechanism. Through in situ uniaxial compression experiments it is discovered that the characteristic bottom‐to‐top sequential buckling proceeds by first nucleating on the bundle surface and subsequently propagating laterally through the bundle, gradually collapsing the entire structure. The effects of strain rate are explored, and storage and loss stiffnesses are analyzed in the context of energy dissipation.