Formation of Poly(vinyl alcohol)/SWNTs Fibers with Hierarchical Structure under High-Speed Shear Flow

Abstract

This study introduces a facile method to prepare syndiotactic poly(vinyl alcohol) (s-PVA) fibers containing singlewalled carbon nanotubes (SWNTs) from the corresponding composite dispersions with tea polyphenols (TP) as dispersant under high-speed shear flow. The formation of the composite fibrous precipitates at high shear rate is largely facilitated by the SWNTs in the dispersions and slight flow resistance. Interestingly, the obtained s-PVA/SWNTs composite precipitates possess a three-level hierarchical structure, that is, a single fiber is assembled by fibrils which are composed of microfibrils of s-PVA-coated SWNTs. And the s-PVA fibrous precipitates containing high amounts of SWNTs could be obtained by shearing the dispersion with relatively low SWNTs loadings, as a result, the composite fiber containing 20.7 wt% SWNTs was prepared from the dispersion with 10.0 wt% SWNTs. In addition, with the increase of SWNTs loadings, the amount of the precipitates increases, but crystallinity of the precipitates decreases instead.