Simultaneous improvement in tensile strength and adsorption capacity of activated carbon fibers during stabilization and activation of acrylic fibers

Abstract

Simultaneous effects of stabilization degree, activation temperature and activation stretching on the adsorption and mechanical properties of acrylic-based activated carbon fibers (ACFs) were studied. ACFs were prepared by the stabilization of the acrylic fibers with different conditions; subsequently, they were impregnated in the KOH solution and activated at three different temperatures under three distinct imposed stretches. Tensile strength index, aromatization index, elemental analysis and density were used to evaluate the degree of the stabilization of the oxidized acrylic fibers prior to activation. The optimum conditions that led to the fabrication of high iodine adsorption and tensile strength ACFs were the stabilization degree of 56.2%, the activation temperature of 800 °C, and the stretching of 1%. The experimental iodine number and tensile strength of ACFs in the mentioned conditions were about 865 mg/g and 423 MPa, respectively. The results of the BET analysis for the optimized sample showed a surface area of 561 m2/g with an average pore diameter of 2.7361 nm. Moreover, the obtained ACFs were well characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscope and CCL4 adsorption test. Simultaneous improvement in the tensile strength and the adsorption capacity could make them suitable for possible high performance applications.