ウェット塗布膜乾燥過程の評価技術

抄録

In this article, we attempt to provide a brief guide to the recent progress in experimental techniques to monitor the transient drying process of multicomponent thin liquid film coatings. First, we report simultaneous measurements of the heat-fluxes and masses of coatings, which allow us to determine the drying rates of two different solvents as a function of the drying time. Second, we demonstrate that, in drying suspensions that contain particles of varying sizes, the photo-luminescence measurement in the course of drying is a powerful tool for capturing the migration of small particles to the top surface. However, the depth-concentration profiles of the particles are not directly determined by this technique. As an alternative tool to capture the concentration distributions in a drying coating, we introduce confocal Raman spectroscopy and reportits recent application in phase-separating polymeric coatings by utilizing a novel solvent-replacement technique. Finally, we reporton a cantilever beam-deflection technique to measure the stress developments in a drying coating. A combination of these techniques may provide a new horizon toward a fundamental understanding of the microstructural development of drying multicomponent films.