Structurally compared, the active capital contains a large number of micropores, has a large specific surface area ,500 m2/g or higher, there are many kinds of adsorbed compounds, and the adsorption capacity is large. Graphitic carbon black was calcined at high temperature and high pressure to remove the heteroatoms on the active inflammatory surface, and the surface formed the most compact arrangement and rigid structure, without pores, and the specific surface area was approximately 100 m2/g.
In the adsorption mode, the porous structure of activated carbon determines that it is a multi-layer absorption, while graphitic carbon black is a single-layer absorption mode. At constant temperature, when the pressure increases to a certain value, the single-layer adsorption saturation begins after the multi-layer absorption. The difference in the absorption mode leads to the adsorption capacity of graphitic carbon black much smaller than that of activated carbon.
On the force, the activated carbon contains heteroatoms, porous structure, large surface activity and uneven distribution. The type of force generated on the compound is much more than that of graphitic carbon black, and the possibility of chemical adsorption and reaction is higher. The hexagonal structure of graphitic carbon black surface makes it have strong adsorption for planar molecules or molecules containing planar aromatic rings.
Activated carbon is porous, graphitic carbon is non-porous, in pesticide residue analysis pretreatment, adsorption with activated carbon, a lot of pesticides are non-eluting applications, activated carbon is quite widely used in industry, but in chromatographic field (including SPE), graphitic carbon black has more obvious advantages, because the rules of adsorption and elution of compounds on graphitic carbon black are easy to grasp. Graphitic carbon black has a strong adsorption ability to pigment. As long as the sample can still distinguish colored pigment after GCB treatment, it can be judged that the recovery rate of agricultural residue in the sample will not be significantly affected, which is why GCB have been widely used in agricultural residue detection. Compared with activated carbon, it is much more difficult to get a good recovery rate because of many active sites and complex forces.
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