Diffusion of water through palm leaf materials

Leaf sheath from Areca catechu palm is showing promise as a plant material for manufacture of eco-friendly food packaging, and as a sustainable material substitute for plastics. Here, we report on a study of diffusion of water through the sheath since water penetration affects the structural integrity of the material, controlling product life. We characterize the diffusion using mass gain measurements, and in situ observations of water transport through the sheath. The diffusion coefficient is estimated using a model that incorporates effects of material porosity, and swelling due to water penetration. Parametric effects of water temperature and salt concentration on the diffusion are characterized. The in-situ imaging reveals the role of microstructural features such as matrix and fibers in influencing water penetration. The results are of value for estimating product life, developing strategies to reduce water penetration in plant leaf materials, and for better understanding liquid transport in plant materials.