Anchoring Structure of Binary Mixture of Liquid Crystals Studied by Scanning Tunneling Microscopy

Publisher Website
Google Scholar
Abstract
The anchoring structures of the binary mixture of 4′-n-octyl-4-cyanobiphenyl (8CB) and 4′-n-decyl-4-cyanobiphenyl (12CB) on molybdenum disulfide (MoS2) are directly observed, with molecular resolution, by scanning tunneling microscopy (STM) for the first time. The STM images indicate that the technique not only resolves the individual molecules, but it also makes a clear distinction between the 8CB and 12CB molecules by their different alkyl chain lengths. The binary mixture takes a bilayer (double-row) structure, consisting of an 8CB subunit and a 12CB subunit, while the pure 8CB molecules do not show a bilayer, but a monolayer (single-row) structure on MoS2. The ratio of 8CB and 12CB adsorbed on MoS2 substrate is different from that in the bulk.