Co-axial electrospinning technique has proved to be a reliable way of producing thin and small hollow fibers with a symmetric or asymmetric structure that may be useful for water treatment. All the hollow fibers produced had an inner diameter of up to 4 µm and average wall thickness of 600 nm. Poly(vinylidene fluoride-co-hexa fluoro propylene) hollow fibers exhibited a dense structure while the addition of poly(ethylene glycol) changed its structure to an asymmetric one, with a dense layer on both inner and outer sides. The semicrystalline copolylmer fibers exhibited a fibrillar structure. Hollow fibers made of the homopolymer poly(vinylidene fluoride) exhibited an asymmetric structure, while polysulfone or poly(ether imide) hollow fibers exhibited a symmetric porous structure.
- co-axial electrospinning
- hollow fibers