Fig. 5.

Atomistic simulations to demonstrate the hydrogen bond breaking and reforming events among cellulose molecular chains. (A) Simulation model of a cellulose bundle contains seven cellulose molecular chains. Top view only shows the middle three chains for visual clarity. (B) Variation of total potential energy as a function of the sliding displacement of the center cellulose chain out of the bundle. (Insets) Clearly shown are the hydrogen bond breaking and reforming events (dotted circles), each of which dissipates energy. (C) Relative cellulose chain-sliding, during which a series of hydrogen bond breaking and reforming events happen (in boxed region) when neighboring hydroxyl groups come close to each other.