Alignment of extremely long single polymer chains by exploiting hydrodynamic flow

Lining up: Polyisocyanide derivatives bearing L-alanyl-D-alanine methyl ester side groups (PIAA) have been adsorbed on the surface of muscovite mica. Scanning force microscopy images reveal single polymer chains with contour lengths ranging from several hundred nanometers up to several micrometers. Their orientation on the micrometer scale is attributed to hydrodynamic flow during the sample preparation (see figure). These long and stiff polymers, which exhibit a persistence length of 76 nm if equilibrated on a surface, can possess an even higher anisometry when brought into non-equilibrium states.