The role of water for the structure and function of biological systems is a well studied topic. In particular, water molecules that bind to biomolecules were found to affect both structure and dynamics of folded proteins, as well as catlytic activity. The plant cell wall is a bilogical nanocomposite constsiting of stiff cellulose fibrils in a soft matrix of other biopolymers. In the native state, the plant cell wall is always saturated with water leading to a water content of around 30% by weight. Isolated cell wall polymers are hygroscopic leading to high moisture uptake even at low relative humidity. This may pose a problem in the development of biobased materials. At the same time, excessive drying can affect material properties negatively through structural changes on the molecular scale. However, recently it was proposed that water may contribute positively to the mechanical properties of cell walls. Specifically, molecular water confined at interfaces was shown to increase both strength and toughness in computer simulations of cellulose fibril aggregates. This means water is there for a reason. In this project we will use MD to study confined water in wood bipolymer systems, focusing on the properties of the water itself. Of specific interest is how i) the extent of confinement (relevant length scales) and ii) the chemical nature of the confining phase affect water properties: diffusion, structure, and thermodynamics. Experiments show that such confined water is quite immobile. This means that long time scales have to be considered. We have previously used simple geometries to model the confinement but here we aim to model more realistic models by considering larger fibril aggregates and to include other cell wall biopolymers, eg hemicelluloses.