Organisation of designed nanofibres assembled in filaments via flow alignment

Well-aligned polymeric nanofibres have been prepared by a simple but effective melt-spinning procedure. The influence of the extrusion process of a diblock copolymer polystyrene-block-poly(4-vinylpyridine) (PS-block-P4VP) hydrogen bonded with surfactant [Ikkala et al., Science 2002, 295, 24071 pentadecylphenol (PDP) on orientation and their structural features have been investigated. Atomic Force Microscopy (AFM) and small angle X-ray scattering (SAXS) demonstrated that the resulting nanofibres were based on PS cylinders within P4VP(PDP) matrix. The large scale orientation of the PS cylindrical structures were formed by microphase segregation in the melt when low flow rates were applied. The diameter of PS nanofibres in P4VP(PDP) matrix was about 90 nm. After removing the PDP surfactant with suitable solvent, polymeric nanofibres were obtained with diameter of I 10 nm. The diblock copolymer nanofibres were formed from a PS core with P4VP shell and were more than 15 pm long. These nanofibres can be produced in large quantities, because extrusion is a continuous process. They can serve as templates for further modifications such as metallization or as components for composites with other materials.