Thermodynamic Explanation
Thermodynamic explanations for moisture lag in porous solids suggest that the material is composed of many small, separate regions that react differently to water vapor. The everett independent domain theory proposes that these microscopic domains within a fiber or fabric switch between dry and wet states at different humidity thresholds. Each domain acts independently, meaning the state of one does not force the state of its neighbor.
Domain Mechanism
Hysteresis occurs because the humidity level required to fill a domain with water is higher than the level required to empty it. When applying everett independent domain theory to cotton fibers, researchers visualize the internal lumen and cell wall pores as these separate domains. This explains why the moisture content is higher during the desorption phase of a cycle.
Fabric Behavior
Complicated mixtures of synthetic and natural fibers display multiple layers of domain behavior. The theory allows for the prediction of how a blended yarn will reach equilibrium when exposed to fluctuating warehouse conditions. By treating each fiber type as a collection of domains, a mathematical model can estimate the total moisture uptake of the fabric.
Theory Limit
Applicability of this model assumes that the domains do not interact or change their physical shape when they absorb water. In reality, some fibers swell significantly, which can merge domains or create new ones during the process. The theory serves as an approximation that works best for rigid or semi-rigid structures where pore geometry remains relatively stable.
