Selective water sorbents for multiple applications, 9. Temperature independent curves of sorption from theory of volume filling of micropores

The theory of the volume filling of micropores is used to describe the water sorption on composite sorbents containing CaCl2 and LiBr confined in various nanoporous matrices (silica gel, alumina, porous carbon Sibunit). This approach yields temperature independent characteristic curves of the water sorption at temperature T = 300 - 410 K and relative humidity eta < 0.9 with the free energy Delta F as a single independent parameter. In the whole range of sorption values N the best approximation of the function log N(Delta F) is a second order polynomial expression. At intermediate sorptions the Dubinin - Astakhov equation gives an analytical description of these curves with an error of about 2 - 5 %.