Prospects in application of thermal analysis for assessing the total water potential of soils

Resumo

The theoretically derived dependence of the water vapor density (concentration) in the air on the absolute temperature permitted us to use the information obtained by thermogravimetric method for assessing the total potential of water remaining in colloids after drying at different temperatures. A close correlation and corresponding linear relationship fitting the fundamental physicochemical law by Landau–Derjaguin were observed between the logarithm modulus of the total potential of moisture left in soil colloids after drying at temperatures 27–70° and 70–200°C and their moisture. The total potential of water bound by hydrates and crystalline hydrates of substances in the soils varied in the range from–660 to–2394 J/g water, and that of water bound in soil clay minerals varied in the range from–714 to–2814 J/g water (which corresponds to the total soil water pressure of–7140 to–28140 atm.).