5. Obtaining adsorption-desorption isotherms

5.1 Sample preparation

Prior to any adsorption, the surface of the samples studied must be cleaned of any species retained by physical adsorption.

In theory, it would be sufficient to create a high vacuum above the sample; in practice, heating the sample is required to accelerate desorption. However, it is important to choose a temperature that will not degrade the sample (as in the case of organic solids) or alter its surface properties.

Sample processing conditions can be optimized by prior thermal analysis, in particular by thermogravimetry