Single wall carbon nanotube templated oriented crystallization of poly(vinyl alcohol)

• Published in: Polymer (Guilford) Vol. 47; no. 11; pp. 3705 - 3710
• Main Authors: Minus, Marilyn L., Chae, Han Gi, Kumar, Satish
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 17.05.2006; Elsevier
• Subjects: Applied sciences; Carbon nanotubes; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Orientation; Poly(vinyl alcohol); Polymer industry, paints, wood; Technology of polymers; Carbon nanotubes; Orientation; Poly(vinyl alcohol); Directional solidification; Tape; Shear flow; Synthetic fiber; Electron beam; Crystallinity; Experimental study; Polyvinylalcohol; Radiation resistance; Singlewalled nanotube; Molecular orientation; Oriented polymer; Morphology; Solution crystallization; Nanocomposite; Atactic polymer
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2006.03.076

Shearing of poly(vinyl alcohol) (PVA)/single wall carbon nanotube (SWNT) dispersions result in the formation of self-assembled oriented PVA/SWNT fibers or ribbons, while PVA solution results in the formation of unoriented fibers. Diameter/width and length of these self-assembled fibers was 5–45 μm and 0.5–3 mm, respectively. High-resolution transmission electron micrographs showed well resolved PVA (200) lattice with molecules oriented parallel to the nanotube axis. Nanotube orientation in the self-assembled fibers was also determined from Raman spectroscopy. PVA fibers exhibited about 48% crystallinity, while crystallinity in PVA/SWNT fibers was 84% as determined by wide angle X-ray diffraction. PVA and carbon nanotubes were at an angle of 25–40° to the self-assembled fiber axis. In comparison to PVA, PVA/SWNT samples exhibited significantly enhanced electron beam radiation resistance. This study shows that single wall carbon nanotubes not only nucleate polymer crystallization, but also act as a template for polymer orientation.