초록 |
Hierarchically structured, gradient concentric rings of regioregular conjugated polymer, rr-poly(3-hexylthiophene) (rr-P3HT) with randomly or directionally crystallized nanofibrils over large areas were obtained by regulating consecutive “stick-slip” motions of the three-phase contact line in a confined geometry consisting of a upper curved sphere surface and a lower flat Si substrate (i.e., sphere-on-flat geometry), which leads to an axially symmetric capillary-bridge (bound solution). Self-organized concentric P3HT ring patterns resulted from mediating intermolecular interactions between the polymer molecules, and varying the solvent concentration. These unusual, directionally crystallized structures were formed spontaneously parallel to the moving direction of the contact line on solvent evaporation. Subsequently, I-V characteristics of the directionally crystallized and randomly distributed P3HT nanofibrils formed across the electrodes were investigated and compared. |