Hierarchically Structured Regioregular Conjugated Polymer via Evaporative Self-Assembly*

Regioregular conjugated polymers, poly (3-hexylthiophene) (P3HT) toluene solution was confined in a sphere-on-flat geometry. The geometrically constrained P3HT solution led to the formation an axially symmetric liquid capillary bridge, from which the consecutive ``stick-slip'' motion of the contact line of the solution due to the solvent evaporation was effectively regulated. As a result, hierarchical ``snake-skin'' like structures of high regularity were yielded, namely, the microscopic structures were composed of P3HT nanofibers. This facile, \textit{one-step} technique based on evaporative self-assembly opens up a new avenue for organizing semicrystalline conjugated polymers into two-dimensional patterns in a cost-effective and nondestructive manner