Why Does Activated Alumina Adsorb?

Why does reactive alumina have adsorption and drying functions? The adsorption of activated alumina can be divided into physical adsorption and chemical adsorption, because of the difference in molecular force between the surface of activated alumina and the adsorbent, today Xiaobian will talk to you about this topic.

In the physical adsorption of reactive alumina, the adsorption is generated by intermolecular forces between the adsorbent and the adsorbent. In the chemisorption of activated alumina, the adsorbed molecules chemically react with the atoms on the surface of the adsorbent, resulting in electron transfer, atomic rearrangement, destruction, and chemical bonding between activated alumina and the adsorbent. Physical adsorption occurs in the active adsorption and drying regions of alumina. The physical adsorption has the following properties.

1. The adsorption force is small and the adsorbed gas molecules tend to return to the gas phase, that is, "desorption".

2. The physical adsorption process of activated alumina is reversible, almost does not require activation energy (even if it is small), and the adsorption speed and desorption speed are very fast, so it can be assumed that activated alumina and adsorbent adsorbate adsorb immediately.

3. All adsorption processes of activated alumina are exthermic reactions. The "heat of adsorption" released by physical adsorption is far less than the heat of chemical adsorption, and the heat is close to the heat of evaporation in the liquid state of the adsorbent or the heat of condensation in the gas state.

4. Physical adsorption is not selective, that is, due to the difference in adsorption capacity, all solids can adsorb gas (adsorption capacity is too small adsorption has no practical application value).

5 The physical adsorption of activated alumina is related to condensation, so it can only be carried out below the boiling point of the adsorbent.

Zibo Yishengjia Aluminum Co., LTD., is a professional engaged in high purity materials research and development, production and sales of science and technology enterprises. The purity of activated alumina produced by the company can reach 99.9% or more, and the pore volume, pore size, specific surface area can be regulated according to customer requirements. Welcome small partners to consult!