Correlation between roughness of nanowires and polymer backbone conformation

The roughness of the side wall of nanowires prepared by single particle negative-tone imaging (SPNI) is quantitatively analyzed. This leads to the estimation of line-width roughness originated from the polymer molecule used. The intrinsic cylinder-like shape of the nanowire allows direct observation of the side walls by scanning probe microscopy, allowing observation of the shapes of the polymer molecules. Polystyrene derivatives were chosen as the target polymer material to discuss the effect of shapes of molecules and cross-linking reactions on the structure of nanowires. The heavy ion particles impinging on the target polymers can release high-density intermediates within a limited area around the ion projectile. Irradiation of the polymers results in a cross-linking reaction around the ion track, resulting in the formation of a cylinder-like nanowire structure corresponding to each ion projectile.