On Measurement of the Pore-Size Distribution of Contractive Plant Material

To obtain the pore-size distributions of contractive tobacco material, tobacco samples of various water content were dried by critical-point drying and pore-size distributions were measured by N2 adsorption isotherms. From these pore-size distributions, the adsorption equilibria of weter on tobacco were calculated. The calculated values agreed well with experimental adsorption data. It was found that critical-point drying prevented the contraction of tobacco. This method is therefore suitable for pretreatment in measuring the pore-size distribution by N2 adsorption isotherm. As a result of this measuring, it was also found that micropores of 1-2 nm radius increased remarkably with increasing water content.