Judging the conductivity of carbon black by oil absorption index
The oil absorption value (DBP) is often used to represent the structure, and the larger the DBP value, the higher the structure. The physical properties and conductivity of conductive carbon blacks depend on the volume and degree of microporosity of these aggregates. The greater the oil absorption value of conductive carbon black DBP, the easier it is to form aggregates with more particles and complex structures, and the more aggregates per unit mass. Therefore, under certain conditions, the greater the DBP oil absorption of carbon black, the stronger its conductivity. Based on the particles that make up the basic aggregates and morphology of carbon black, highly structured carbon black aggregates have large and high-molecular groups of particles. This branching increases the contact between aggregates, which can lead to high electrical conductivity.
Judging the conductivity of carbon black by the specific surface area index
At the same time, the larger the specific surface area of conductive carbon black, the more aggregates per unit mass. That is, the higher the structure, the larger the specific surface area and the stronger the conductivity.
Judging the conductivity of carbon black by impurity index
The impurities of carbon black mainly represent the purity of carbon black, and the higher the purity of carbon black, the better its electrical conductivity.
Judging the conductivity of carbon black by the structure of carbon black
The conductivity of carbon black mainly depends on the structure of carbon black, and there is no such thing as structure in general carbon black indicators, but the structure of carbon black is a unique and very important property, which means very fine carbon black The degree to which particles aggregate into chains or grapes. The higher the structure, the more developed the chain (or grape-like) structure, and the easier it is to form a carbon black space network channel structure. This structure is the smallest basic unit that can be maintained when dispersed, and is not easy to be destroyed. Carbon black in high polymer species It exists in aggregates as the basic unit, and particle aggregates and polymers are permanently fused together during production and processing, unless there is too strong a shearing action.
If you want to buy conductive carbon black with high conductivity, you can judge it by the oil absorption value, specific surface area and impurities of carbon black. Of course, the structure of carbon black is also very important.