Polymer, Vol.43, No.3, 775-780, 2002
Generation of electrospun fibers of nylon 6 and nylon 6-montmorillonite nanocomposite
Dissolution and reprocessing of exfoliated montmorillonite-nylon 6 (NLS) nanocomposite is demonstrated, illustrating the potential of using polymer nanocomposites as the foundation for fabricating nano- and mesoscopic structures, nanofibers in this case, and thus exerting hierarchical control of morphology and form through the combination of a nanostructured material and a nanoscale fabrication technique. Exfoliated morphology, present in the melt-fabricated NLS nanocomposite, was preserved in cast films and electrospun fibers from hexafluoroisopropanol solution. However, addition of a few percent N,N-dimethyl formamide resulted in agglomeration of the dispersed montmorillonite layers and an overall mixed morphology, demonstrating solvent partitioning and the delicate enthalpic balance necessary to maintain layer dispersion. Fibers and nanofibers of NLS nanocomposite (diameters between 100 and 500 nm) were electrospun from solution, and collected as non-woven fabrics, or as aligned yarns. Together with these cylindrical shaped fibers and nanofibers, ribbon shaped fibers (width similar to 10 mum, thickness similar to 100-200 nm) were also found in the products. The electrospinning process resulted in highly aligned montmorillonite layers (layer normal perpendicular to the fiber axis) and nylon 6 crystallites (layer normal parallel to fiber axis).