Differential scanning calorimetry has been used to study the thermal effects during adsorption and desorption of water on
different zeolite NaA samples. An attempt has been made to compare the thermal behaviour of a layer of zeoliete attached on
metal ("by chemical bond") with zeolite powder pressed on metal. The dependence of the water uptake on temperature has been
studied with a powdered sample.
Isothermal measurements of the water uptake of the zeolite after activation, appeared the best way to determine the heat of
adsorption. Calibration of the DSC was needed. The adsorbed amounts of water corresponding to the released heats were determined
thermogravimetrically. Once the heat of adsorption is known, it is possible to determine the mass of active zeolite of thin
synthesized zeolite layers on metal with DSC.