Effect Of The Pretreatment Of Polyacrylonitrile(PAN) On The Pre-Oxidation Of Carbon Fiber And Preparation And Supercapacitor Characterization Of Copper-doped Activated Carbon From PAN

Carbon fiber is a kind of new carbon material made of polyacrylonitrile (PAN) through pre-oxidation, carbonization and graphitization processes. Pre-oxidation is the most important process which consumes the longest time. However, some problems exist in the pre-oxidation process which contains the melted fusing of PAN precursors caused by the fast heat release of a series of chemical reactions. Also the initial reaction temperature of pre-oxidation is so high that it imposes a challenge on the production cost. Great efforts were paid in this paper to overcome these problems and try to find some pretreatment reagents which can decrease the initial reaction temperature and the amount of heat release. PAN contains a high amount of nitrogen elements and possesses a high carbon yield which makes it the candidate to prepare activated carbon. The activated carbon materials have the great potential application in the supercapacitor fields. The main studies in this paper are shown below:(1) Pretreatment of PAN precursor before pre-oxidation is a selective approach to resolve the existed problems. Pretreatment reagents could react with PAN precursor to change the composition and the crystallize structure which contributed to the reduction of the initial reaction temperature and the amount of heat release. DSC, FTIR, SEM were used to test the results of pretreatment. Many efforts were paid in order to find the candidate pretreatment reagent which could resolve the problems without damaging environment.(2) PAN has a high amount of nitrogen element and carbon yield which was the candidate material to prepare activated carbon.In this study we used KOH as the activation reagent to produce activated carbon by chemical activation process. The optimum experimental conditions were studied to get the highest BET surface. The activated carbon reached the highest BET surface when the weight ratio of KOH to PAN precursor at 800 degrees. The activated carbon can be used to prepare electrodes of supercapacitor. Trying to improve the supercapacitance of activated carbon copper-doping process was carried out. PAN was first functioned by NH2OH to introduce a number of hydrogen and amino groups which could complex with copper ions in solution. After activation process we got the copper doped activated carbon having a higher capacitance than that of none doped activated carbon.