Fabrication of poly(vinyl alcohol)s (PVAs) nanotubes through the fusion of nanocapsules composed of PVAs multilayer films

Poly(vinyl alcohol) (PVA) nanocapsules were fabricated by the deposition of PVA multilayer films onto the surface of silica particles followed by the removal of the silica cores. When a water dispersion of PVA nanocapsules was dried on a substrate, PVA nanotubes were formed through the one-dimensional fusion of the nanocapsules. This fusion behavior of the PVA nanocapsules was strongly affected by the molecular weights and acetylation degrees of PVA, the capsule film thickness of the PVA nanocapsules and the temperature to dry a water dispersion of the nanocapsules. When nanocapsules composed of 20 layered films of acetylated PVA with a 14% acetylation degree were used, nanotube formation via the fusion of these nanocapsules occurred effectively upon drying the water dispersion at 20 °C.