Shear-induced uniaxial assembly of polyaromatic monolayers

The control of spatial arrangements of molecular building blocks on surface opens the foundational step of the bottom-up approach toward future nanotechnologies. Contemporarily, the domain size of monolayers exhibiting crystallinity falls in the submicron scale. Developed herein is a method that allows the alignment of polyaromatics with one-single domain for as long as ∼7 mm. Even more exciting is the fact that the method is applicable to every laboratory with negligible cost. The monolayers are prepared simply by placing a piece of folded lens paper against the substrate and the deposition solution containing the compound of interest. The essence of the film preparation is similar to the Couette flow where the laminar flow takes place between two concentric walls, one of which rotates and creates viscous drag proven useful to align macromolecules. The method can induce an edge-on orientation for,6,11,14-tetradodecyloxydibenzo[g,p]chrysene (DBC-OC₁₂), hexakis-(4-dodecyl)-peri-hexabenzocoronene (HBCC₁₂) and 3, 6, l2, 15-tetrakis-(dodecyl)-tetra-benzl[a. c. h. j]anthracene (TBA-C₁₂), which would otherwise adopt the face-on arrangement on graphite.