Observation of a solitary rigid molecular chain cilium standing on poly(p-phenylene benzobisthiazole) lamellar crystal

The rigid polymer, poly(p-phenylene benzobisthiazole), crystallized from H₂SO₄, formed a lamellar crystal in which the polymer chains were oriented perpendicular to the lamellae. It was supposed that the lamellar surface bristled with chain cilia because of wide distribution in the polymer chain length. This region of the bristle would be a transitional structure from full to deficient packing of the polymer chains. Ordinary scanning probe microscopy of the bristled lamellar surface permitted depiction of a layer with a constant population of the cilia. In this work, the method for imaging one single polymer chain end standing on the lamellar surface was developed. From the image it was concluded that an isolated, long cilium did not move extensively at room temperature. In addition, the three-dimensional chain end distribution was determined by several tens of scannings with consecutively varying input energy of the cantilever.