Diffusion of water in palm leaf materials

Area of Science:

• Materials Science
• Plant Biology
• Biomaterials Engineering

Background:

• Water diffusion impacts plant material properties like strength and formability.
• Areca palm leaf sheath is a hierarchical plant material used in sustainable foodware.
• Understanding water transport is key for optimizing processing and product longevity.

Purpose of the Study:

• To characterize water diffusion in areca palm leaf sheath.
• To investigate the influence of material swelling on diffusion coefficients.
• To analyze microstructural effects on water transport and salt concentration impacts.

Main Methods:

• Mass gain measurements and in situ imaging to study water transport.
• Homogeneous ensemble model incorporating swelling effects to estimate diffusion coefficient.
• High-resolution imaging and image correlation to map microstructural diffusion and strain.

Main Results:

• Estimated water diffusion coefficient D = (6.5 ± 2.2) × 10⁻⁴ mm²/s, with swelling significantly impacting accuracy.
• Water diffusion is ~10x faster in the matrix (8.63 × 10⁻⁴ mm²/s) than in fibers (7.19 × 10⁻⁵ mm²/s).
• Observed non-monotonic dependence of diffusion on NaCl concentration.

Conclusions:

• Accurate water diffusion modeling in plant materials requires accounting for swelling.
• Hierarchical structure of areca sheath leads to anisotropic water transport.
• Findings can inform improved manufacturing of eco-friendly foodware from plant-based materials.