Chitosan interphase around nanodiamond: Insight from equilibrium molecular dynamics

Abstract In the context of nanodiamond/chitosan (ND/CS) nanocomposites and utilizing atomistic molecular dynamics, the interaction mechanism of adsorbed CS layer around a model ND has been investigated at three level of hydration: in bulk of water, water as a droplet, and completely dry condition. The effect of amination and carboxylation of ND has been studied. To ensure that the comparison of these model systems is meaningful (energetically and geometrically), the CS interphases around NDs were characterized through holistic concentration profiles and density distribution maps. Our results revealed that in a completely dry condition or hydrated by a molecularly small droplet, both of the functionalized NDs are having much stronger adhesion interactions compared with the non-functionalized ND with the dominance of electrostatic mechanism. However, hydrated by large amount of water with implication to solutions, interfacial adhesion energies between ND and CS are the same through van der Waals mechanism.