| Activated carbon fibers (ACFs) are widely used in sewage treatment, water purification, organic solvent recycling, gas purification, electrode of super-capacitor, fuel cell and so on, due to their small pore size and narrow pore-size distribution, high specific surface area and abundant functions, and so ACFs are thought as promising materials in the domain of adsorption and separation in this century. In this study, ACFs were prepared from general pitch-based carbon fibers by catalytic activation method, and how to control the pore-size by varing preparation process conditions was researched. The capacitance proformance of the resultant ACFs were studied, and a method was introduced to test the dynamic adsorption of toluene on ACFs. The adsorption and regeneration properties of different pore-size ACFs were analized. The major work is as following:1. Activated carbon fibers were prepared from general pitch-based carbon fibers by catalytic activation method. The surface morphology of resultant activated carbon fibers before and after diluted acid washing as well as activated carbon fibers without cobalt immersion was observed with SEM, and their difference was investigated. The results showed that the surface of carbon fibers activated with cobalt immersion have more mesopores and macropores than the one without cobalt immersion. More abundant pore structure was obtained by washing the fibers with diluted acid. The specific surface area of activated carbon fibers was increased by prolonging the activate time, but the pore-size of ACFs was not broadened.2. Electrochemical performance of activated carbon fibers as electrodes of super capacitors were characterized by galvanostatic measurements, cyclic voltammograms and AC impedance spectrum analysis. The electrode performance showed that the specific capacitance of activated carbon fibers washed with diluted acid was 197F·g-1, 50% higher than that of the one without cobalt immersion. At the current density of 1500mA·g-1, specific capacitance reached 163F·g-1, and after 2000 DC charge/discharge cycles, the specific capacitance increased by 23%. Carbon fibers activated with cobalt immersion and washed with diluted acid would be promising electrode materials for super-capacitors.3. Continuous sample introduction on GC method was used to test dynamic adsorption of toluene on ACFs. The relationship of breakthrough time, adsorption amount of toluene and specific surface area of activated carbon fibers under the same adsorption condition was analyzed, and comparison was made with interval sample introduction method. The results showed that the adsorption amount of toluene was well related with the specific surface area of activated carbon fibers. The breakthrough time also had a good relationship with specific surface area of activated carbon fibers, and it could be used as one index to characterize the difference of specific surface area. Compared with interval sample introduction method, continuous sample introduction method was very simple to operate, and it was a high efficienct and quick way to test the breakthrough curve of activated carbon fibers, which could describe the breakthrough curve finely.4. The dynamic adsorption of toluene on differnt ACFs and the dynamic adsorption of toluene under different concentration were researched. The results showed that the dynamic adsorption of toluene was 80% of the saturation under low toluene concentration. The adsorption amount of toluene was well related with the specific surface area of activated carbon fibers. The dynamic adsorption of toluene was as high as 1250mg·g-1 on the ACFs which was preparation by catalytic activation method. The dynamic adsorption of toluene can keep 900mg·g-1 after 20 cycles.
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