Methods For Structural Control Of Carbon Fiber Automotive Accessories

1: The pore size of carbon fiber auto parts is mainly micropores, and the distribution is monodisperse type, suitable for gas phase adsorption and low relative molecular mass molecules (less than 300) liquid phase adsorption. According to different application fields, it is necessary to control and adjust the aperture of carbon fiber auto parts by using controlled activation process, catalytic activation method and evaporation method. If a certain amount of KOH is added to the carbon precursor of different types and forms, and then carbonized at a certain temperature, the activated carbon and activated carbon fiber auto parts with large specific surface area can be formed, and the microcrystalline structure of the fine crystallization trend is very obvious.   By using chemical vapor deposition (CVD), Chida et al. in Japan found that small molecule hydrocarbons such as benzene can be deposited on the pore wall of carbon fiber auto parts to produce molecular sieve carbon fiber auto parts with controllable pore size and can separate methane and carbon dioxide. More rigorous aperture control is required if N2/O2 separation sieve is to be made.
2: Another way to control the structure is to reactivate carbon fiber auto parts after heat treatment. Ordinary carbon fiber auto parts have poor crystallizability, poor electrical and thermal conductivity, which can not meet the application requirements of fuel cells and capacitors, and it is difficult to increase the number of micropores with the graphitized precursor activation. However, if the carbon fiber auto parts are graphitized for secondary activation, the original missing hole can be used as the active point to form micro-pores again. The surface area increases, and the crystallinity and electrical conductivity are better than that of the carbon fiber auto parts only after one activation. Active carbon fiber auto parts with high specific surface area and high crystallizability can also be obtained after graphitization and ozone oxidation.