Preparation And Properties Of Polyacrylonitrile / Carbon Nanotubes Composite Nanofiber Membrane

Electrospun nanofibers with excellent properties were found to be used in protective clothing, optical sensors, and for solar sails in space. However, the polymer nanofibers fabricated by electrospinning processes were not strong enough for their very small diameter. So making nanocomposites was a more promising way to reinforce the nanofibers. Also, carbon nanotubes (CNTs) had attracted great interests due to their unique mechanical, electrical, magnetic, optical and thermal properties. All of these properties made carbon nanotubes an ideal material for reinforcing polymer materials. So making PAN/MWNTs nanofibers was a better way to reinforce the PAN nanofibers.Continuous composite nanofiber sheets made from polyacrylonitrile (PAN) and surface-oxidized Multiwall Carbon Nanotubes (MWNTs) were successfully fabricated by electrospinning.The acid-treated MWNTs were examined by FITR, TEM, SEM. The results showed that after MWNTs were modified, carboxylic acid groups were found in the surface of MWNTs and MWNTs were well dispersed in DMF.The rheological properties were studied by rheometer. The result exhibited that the rheological properties of the DMF solution of PAN/MWCNTs belonged to pseudoplastic fluid, and shows shear thinning. The rheological properties had greatly related with temperature and shear rate.Scanning electron microscope (SEM) photos showed the change of the morphology of the electrospun PAN/MWNTs fibers according to the differentprocessing parameters. The results showed that when the solution concentration of was 10%,spinning voltage was 20 kV, the distance of collection was 17.5cm, the good morphology of PAN/MWCNTs composite nanofibers electrospun.The properties of nanofiber sheets were studied by SEM, TEM, X-ray, TG and the membrane tensile testing. The results showed that the acid treated MWNTs/PAN nanofiber was smooth and thin. TEM showed that the part of carbon nanotubes were aligned in nanofibers via electrospinning. The X-ray showed that most of MWNTs were not aligned in nanofiber. .The adding of MWNTs greatly improved the mechanical properties of nanofiber sheets, but had no contribution to thermal properties.