Jing zeolite catalysis and adsorption properties of packaging materials and moisture

Jing and zeolite catalysis is a porous material. Some types of finely powdered products or very fine. Therefore they have a large surface area thereof. The internal surface of the atom atom in a different state, the internal atomic attraction uniformly distributed in the circumferential country atom force field to make the saturation equilibrium, while the surface atoms of this force field is not saturated, That surface adsorption force field exists, there is the surface energy. When the gas or liquid molecules into the force field range, it will be adsorbed, thereby reducing the surface energy by the white system. This unsaturated force field scope. Roughly equivalent to the size of the molecular diameter. That is about a few angstroms. Therefore, they have a very clear its adsorption performance is good adsorption Jing.
Depending on the size of adsorption. Adsorption phenomena generally classified into two types of physical adsorption and chemisorption. Physical adsorption force is van der Waals forces. Therefore, similar to the adsorption heat and condensation heat, and the adsorption is reversible adsorption is fast, a greater speed at low temperatures. Chemisorption between the adsorption and chemisorption Jing success key role. Adsorption heat large (> 10kcal / mol, lea [. A 1840J). And the chemical reaction heat is similar but different chemical adsorption and chemical reaction. No new material is generated. Chemical adsorption is irreversible, and must have a high activation force dish surface can be overcome.
Which adsorb moisture in the air is the most common physical adsorption phenomenon. Such as zeolites have play very absorbent sheets can, even at very low partial pressure or concentration. There is still a very high adsorption capacity bi, so no matter what is used. Can get a good depth of dry operation. Or zeolite 3a molecular sieve for ethanol drying catalyst during the activation. Can not completely remove the moisture contained therein, but also more or less finished product prior to packaging certain adsorbed moisture, the moisture of the total sub-Jing or Automobile Desiccation Molecular Sieve catalyst and a percentage of this substance is said to Lang moisture for most packaged goods, usually expressed as a mass fraction II.