Specific surface area of soils with different clay mineralogy can be estimated from a single hygroscopic water content

Hygroscopy as an Indicator of Specific Surface Area in Polymer Materials

“…The study [ 30 ] confirmed that a single measure of hygroscopic water content can provide reliable estimates of the SSA. It proposed regression models to estimate the SSA index from W h for three soil sample groups with different clay and soil organic matter contents.…”

“…Indeed, the analysis of more than 300 soil samples in [ 30 ] revealed a close (R 2 = 0.7–0.95) linear relationship between W h and SSA in the form of SSA = k·W h + m , where k and m are empirical parameters. The parameter m in some cases was close to zero or took negative values.…”

“…In these studies, the calculation of SSA from water vapor sorption isotherms is based not only on the standard BET model, but also on the GAB (Guggenheim–Anderson–de Boer) model, which is more adequate for S-shaped curves of water vapor sorption isotherms by polymeric materials [ 24 , 27 ]. A number of researchers emphasize the close correlation of the SSA index and the hygroscopic water content of materials, which is obvious, since the larger the surface, the higher the adsorption of water vapor from the air [ 28 , 29 , 30 ].…”

“…This indicator is especially important in atmospheric chemistry, pharmaceuticals, and materials science, where hygroscopicity strongly affects the functioning and technological properties of dispersed systems (aerosol particle size, light absorption and transmission, powder aggregation, their wettability and solubility, change in marketable weight at a violation of the sealing of packages, etc.) [ 30 , 32 , 33 , 34 , 35 , 36 ]. In this case, hygroscopicity is studied in a wide range of relative air humidity (water activity) to obtain experimental characteristics in the form of water vapor sorption isotherms or hygroscopic growth functions [ 32 , 37 ].…”

“…Despite the obvious connection between hygroscopicity and SSA, only the rare empirical models mentioned above are known in this field [ 28 , 30 ]. Theoretical approaches to combine these indicators, as far as we know, do not exist.…”