Abstract: To obtain a perfect porous hollow fiber, ployacrylonitrile(PAN)/polyvinyl pyrrolidone(PVP)／N, N-Dimethylformamide(DMF) mixture solution as sheath spinning solution, and PVP/DMF, polyoxyethylene (PEO)/DMF and PVP/ethanol (EtOH) as core spinning solution respectively, composite ultrafine fibers were prepared by co-axial electrospinning. The water-soluble polymers in the composite ultrafine fibers were removed by deionized water under the conditions of ultrasonic vibration. The obtained ultrafine fibers were characterized by field emission scanning electron microscope(FESEM). The SEM observation revealed that the morphology of ultrafine fibers was poor when PVP/DMF solution was used as the core layer; and that ultrafine fibers with porous surface structure could be produced when PEO/DMF solution was used as core layer; and that porous hollow PAN ultrafine fibers could be fabricated only when PVP/EtOH solution was used as core layer.

Key words: co-axial electrospinning, ployacryolnitrile, polyvinyl pyrrolidine, polyoxyethylene, porous hollow ultrafine fiber