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Dynamics of Grain Boundaries in Two‐Dimensional Hydrogen‐Bonded Molecular Networks
Author(s) -
Lackinger Markus,
Griessl Stefan,
Kampschulte Lorenz,
Jamitzky Ferdinand,
Heckl Wolfgang M.
Publication year - 2005
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.200400078
Subject(s) - trimesic acid , grain boundary , terephthalic acid , materials science , molecular dynamics , monolayer , chemical physics , crystallography , ostwald ripening , graphite , hydrogen , substrate (aquarium) , nanostructure , nanotechnology , molecule , composite material , computational chemistry , chemistry , organic chemistry , polyester , microstructure , oceanography , geology
Abstract The temporal evolution of domain boundaries of hydrogen‐bonded molecular monolayers at the liquid–solid interface is evaluated by recording series of subsequent scanning tunneling microscopy (STM) images. Comparison of dissimilar benzene carboxylic acids reveals a clear distinction between one‐ and two‐dimensional H‐bonded network structures. Trimesic acid forms a two‐dimensionally H‐bonded networked structure, whereas terephthalic acid organizes in a dense packing of H‐bonded linear chains on a graphite surface. In addition, TMA forms a sixfold lattice on a threefold graphite substrate, whereas TPA exhibits only a twofold lattice, causing a high grain‐boundary line energy for the latter. In the case of TMA the nanostructure was mostly stable during the observation time. For TPA, Ostwald ripening—that is, the growth of larger islands at the expense of smaller islands—was observed. To explain the various experimentally observed timescales of the dynamics occurring at grain boundaries, molecular mechanics simulations were applied to calculate the binding energy of edge molecules, that is, the line energy, of finite islands of both trimesic and terephthalic acid on a graphite substrate.