Wood is a complex, hierarchical material that has complex interactions with moisture. Fundamentally, most of these properties derive from the how the biomolecules that make up the cell wall ultrastructure react to water. Understanding of how the polysaccharine components of the cell wall: cellulose and hemicellulose respond to moisture changes is improving [1]. However, the role of lignin remains less clear.
Scattering methods allow for non-destructive characterization of wood cell wall components in changing moisture conditions. The results derived from scattering experiments can be compared to computer modeling results from molecular dynamics models of cell wall constituents. 
We have conducted X-ray scattering measurements on delignified wood undergoing a desorption-adsorption cycle and compared the results on previous data of untreated wood going through a similar cycle, in order to explain the role of lignin in cell wall moisture interactions. A molecular model consisting of cellulose, hemicellulose and lignin at different moisture contents was utilized to aid in the interpretation of the experimental results. 
Based on small-angle scattering, delignification noticeably increased the interfibril distances. Wide-angle scattering showed that the presence of lignin does not affect the cellulose crystal structure and how it changes with respect to moisture.  Small-angle scattering from water-saturated, delignified wood also showed a large contribution which was attributed to nanoscale pores, which closed during drying.
Based on both the scattering results and the simulations, lignin seems to be a passive, rather than an active component, in the fundamental moisture interactions of cellulose microfibrils.