Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 46: Poster II

CPP 46.49: Poster

Donnerstag, 12. März 2026, 09:30–11:30, P5

Surface-induced morphology and in-plane order in thin films of polydiketopyrrolopyrroles — •Anton Sinner and Oleksandr Dolynchuk — Martin Luther University Halle-Wittenberg, Germany

Board-like conjugated polymers are of particular interest in the context of surface-induced ordering because they often exhibit a preferred out-of-plane molecular orientation in thin films. Recent studies of ordering in conjugated polymer films have found that the free surface induces the formation of sanidic liquid crystalline (LC) mesophases with out-of-plane, smectic-like positional order between polymer chains. However, the question of whether the surface influences the in-plane order between polymer chains during ordering remained open. Here, we use atomic force microscopy to investigate the surface morphology and nanoscale structure formed on the surface of polydiketopyrrolopyrrole (PDPP) films after slow cooling and ordering from the melt. We find that the surface morphology consists of disc-like crystallites with diameters roughly equivalent to the polymer contour length and heights equivalent to several out-of-plane polymer layers. Thus, the observed LC morphology is consistent with the earlier study of out-of-plane molecular order. On a larger scale, multiple LC discs arrange into string-like morphologies, suggesting the existence of orientational order among them. Quantitative analysis of the surface morphology allows for calculating a distance-dependent orientation correlation function for six-fold symmetry, which indicates the presence of quasi-long-range order on the surface of PDPP films.

Keywords: Conjugated polymers; Surfaces; Liquid crystals; Atomic force microscopy; Orientational order