，关于乙炔炭黑视比容的测定
Acetylene blacks specific surface area (BET) measurement is an internationally accepted technical measurement method for surface area and pore size. It has been widely used in various fields such as industrial catalyst, filler and mineral surface.
Acetylene black is a very small particle size material which can be used to modify the properties of carbon black, rubber and other materials.
The measurement of acetylene blacks specific surface area (BET) is partly based on the theory of Brunauer-Emmett-Teller (BET). The surface area of the material is determined by a physical method of adsorption and the BET method is a widely used surface area analysis method. This method requires an adsorbent, such as krypton or nitrogen molecule, to be used as a reference adsorbent and to be dispersed on the surface of an object.
When an object is coated with a layer of adsorbent, the BET method calculates its specific surface area (BET) as follows:
1. The weight of the sample is calculated, and the volume of the powder is calculated by weighing it.
2. The sample is placed in an adsorption vessel and sealed.
3. A constant stream of krypton or nitrogen is injected into the adsorption vessel at a certain pressure and adsorption is performed until a certain equilibrium pressure is achieved. At this point, the adsorption equilibrium is reached.
4. The amount of adsorbent adsorbed on the surface of the sample is calculated from the equilibrium pressure difference and the isotherm data.
5. The specific surface area (BET) of the sample is calculated by the BET equation.
In the measurement of acetylene blacks surface area by BET, a key point is to accurately determine the amount of nitrogen or krypton adsorbed. This can be done by writing a sample film in the adsorption vessel and determining the adsorption amount by measuring the adsorption capacity.
In summary, the measurement of acetylene blacks surface area (BET) requires several steps, including the determination of the initial weight of the sample, the preparation of the adsorption vessel, the injection of nitrogen and krypton, the determination of the adsorption amount and the calculation of the specific surface area. The accuracy of the measurement depends heavily on the accuracy of the adsorption amount.
