The results of dynamic and quasi-isothermal thermodesorption of water from a silica gel surface at low furnace heating rates
in the temperature range 20–125° are presented. From the experimental results, the water film pressure π on silica gel surface,
the activation energy ΔE and the evaporation heat ΔH were calculated. An interpretation of π changes in relation to the film thickness and wetting process has been proposed.
It is concluded that the characteristic film pressure values correspond to the work of spreading, and immersional, adhesional
and adhesional-cohesional wetting. From the determined film pressure values, the average value of the silica gel polar component,
, was calculated to be 114.67 mJ/m2.