The newly found phenomenon of polymerization-induced epitaxy can produce an ultrathin film of highly oriented polymer molecules on a solid surface. Poly(tetrahydrofuran), poly(oxacyclobutane), and polyethylene oxide) were epitaxially grown on the basal plane of graphite via in situ polymerization and their intra- and interchain structures as well as epitaxial orientations were examined by scanning tunneling microscopy (STM). STM images indicated these polymer chains in a planar, all trans conformation commensurate with the graphite lattice. Different polymer lattices can be constructed by mutually shifting a chain with respect to the adjacent chain along the backbone direction, in units of the graphite hexagon. Most of the STM images can be explained by moir6 patterns generated through rotations of the polymer lattice on top of the graphite lattice. Such a pattern can only be observed if the film exists as a monolayer. Furthermore, we find that the present epitaxial growth process proceeds such that the two-dimensional array that constitutes a basic repeating pattern of a fringe, defined by the number of structural repeating units along the polymer backbone and the number of chains within a commensurate cell, becomes the first two smallest of all other possibilities, namely, one unit, one chain or seven units, seven chains.
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