Abstract
Bio-sourced materials made of xylan reinforced by cellulose whiskers do not generally express optimal mechanical performance; because of poor interfacial stress transfer. Molecular modeling is in principle a choice technique to study the interfacial organization. Unfortunately, with present computing, the time and space scales accessible in full-atoms simulations are not sufficient. To overcome this difficulty, we have developed a coarse grain force field able to describe xylan and its interaction with crystalline cellulose. We then have generated atomistic and coarse grain models of cellulose xylan nanocomposites. In the interface, which was 1.5 nm thick, the xylan chains in the immediate vicinity of the cellulose were oriented parallel to the surface, adopting a mixture of two-fold (dominant) and three-fold (minor) helical conformations interrupted by kinks, they were mainly aligned to each other and inclined with respect to the fiber axis. The models correctly reproduce the experimental data from various sources. The coarse grain approach holds great promises, it may be used not only to estimate the behavior of the interface under various stresses but also to study transport phenomenon in such bionanocomposites.