Migration of cesium chloride dissolved in the liquid water of sugi (Cryptomeria japonica D. Don) during drying at 65°C

Abstract

Abstract The objective of this study was the visualization of the migration of a dissolved substance in the liquid water of wood during drying by means of X-ray imaging. The formation of a characteristic deposition pattern has been observed in the course of drying small pieces of sugi soaked in a cesium chloride (CsCl) aqueous solution. Expectedly, CsCl migrated from the inside to the surface and was deposited just below the surface because of the evaporation of water at the evaporation front. At the end of the drying process, the relative concentration of CsCl at the surface of sapwood samples was determined to be 130%–400% of the initial amount of dissolved CsCl, while the CsCl concentration deep inside samples was below 50%. Sapwood accumulated more CsCl than heartwood did, and the CsCl concentration in latewood was higher than in earlywood.