Extended ensemble molecular dynamics study of cellulose I–ethylenediamine complex crystal models: atomistic picture of desorption behaviors of ethylenediamine

Cellulose I crystals swell on exposure to ethylenediamine (EDA) molecules form a cellulose I–EDA complex, and successive extraction of EDA converts the complex crystalline phase either original or IIII, depending treatment procedure. The present study reports extended ensemble molecular dynamics (MD) simulation models. An accelerated MD allows most desorb from crystal model through hydrophilic channel between piles chains, one at time. Migration single molecule along is simulated by adopted steered method combined with umbrella sampling evaluate potential mean force (PMF) free energy change its movement. PMF continues increase during migration an give final value more than 30 kcal/mol. profiles are largely lowered removal in neighboring channels widening channel. former suggests that desorption cooperates channels, and, latter case, efficiently promoted solvation water expanded We conclude atomistic picture behaviors observed models applicable real phase. Graphic abstract