Assembly of polyamide 6 nanotube arrays with ordered patterns and the crystallization behavior

• The polyamide 6 (PA6) nanotube arrays with ordered patterns were successfully prepared using photolithography via polymer solution wetting the anodic aluminum oxide (AAO) templates.
• The crystalline polymer of PA6 nanotubes were observed by the high-resolution transmission electron microscopy (HRTEM) for the first time.
• The crystal phase transition of PA6 nanotubes from the α-form to the γ-form was detected by the X-ray diffraction.

Highly ordered arrays of polyamide 6 (PA6) nanotubes were successfully prepared using photolithography via polymer solution wetting the anodic aluminum oxide (AAO) templates. The samples were examined by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD). The crystal structure and the crystallinity of the samples were influenced by the presence of nanopores in the AAO template. Nanopore-induced crystal transformation from the α-form to the γ-form of PA6 was confirmed by XRD, and the formation of γ-form crystal was enhanced by the presence of nanopores in the AAO template. The formation of γ-form crystal was also discussed. These results indicated that nanopores provided favorable conditions for the crystallization of γ phase.