Nano-porous ultra-high specific surface ultrafine fibers

Nano-porous ultra-high specific surface fibers havepotential applications in selective absorption-separation,solid support catalysts, composites, high performancesensors, scaffolds for tissue/cell growth, carriers for im-mobilizing biological and pharmacologically significantagents and molecules. It is highly probable that the otherunanticipated but useful properties may be discovered forthese fibers to expand the applications of the fibers to ar-eas that currently do not exist. Since these fi…

Nano-porous ultra-high specific surface ultrafine fibers

Nano-porous ultra-high specific surface ultrafine fibers are created by the method of “electrospinning-phase separation-leaching” (EPL) for the first time. First of all, polymer solutions of polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) blends dissolved in co-solvent are electrospun to make ultrafine fibers when charged to high voltages. The incompatibility of PAN and PVP induces phase separation to form microdomains of PVP in the polymer blend ultrafine fibers. Then, PVP microdomains in the blend fibers are leached out in water, and porous PAN ultrafine fibers are obtained. Lastly, the surface and cross-section of the porous ultrafine fibers are observed in detail by field emission scanning electron microscope (FE-SEM), and the specific surface of the ultrafine fibers is measured by means of nitrogen absorption. With increasing the content of PVP, the specific surface area of the ultrafine fibers increases apparently. The specific surface area of the porous ultrafine fibers with the diameter of 2130 nm is more than 70 m²·g^?1. The cross-section of the PAN porous ultrafine fibers after leaching of PVP microdomains from polymer blend fibers with the feed ratio of PAN/PVP of 10/20 shows the characteristic of porous structure with pore diameter of ca 30 nm according to FESEM photo.