Influence of Oxidation Conditions on Polyacrylonitrile-Based, Activated Hollow Carbon Fibers

Abstract

Polyacrylonitrile hollow fibers are oxidized at three different temperatures and var ious durations, and then further carbonized in nitrogen and activated with carbon dioxide. The influence of oxidation conditions on the properties of the resulting ac tivated hollow carbon fibers is discussed. Activated hollow carbon fibers at the highest oxidation temperature have the lowest mechanical properties, and stick together on the surface due to quick heating during oxidation. The higher the oxidation temper ature, the larger the size of the pores, and the pores are almost always concentrated at the center of the wall of the hollow fiber. However, activated hollow carbon fibers at the lowest oxidation temperature have higher mechanical properties, fewer pores of large size, and larger surface areas, which exhibit greater hysteresis effects in nitrogen adsorbing at low pressure.