Atomic-scale interactions of the interface between chitosan and Fe3O4

Molecular dynamics (MD) simulation was employed to study chitosan adsorption on different Fe3O4 crystallographic planes at the atomic level. The interaction energy between chitosan and different Fe3O4 surfaces indicates that the interaction of chitosan and Fe3O4 (1 1 1) surfaces is stronger than that of (1 1 0) and (0 0 1) surfaces. The concentration profiles show that hydrogen and amino groups of chitosan could form strong interactions with the surfaces of Fe3O4. The radial distribution function show that the probability of forming hydrogen bonds between groups of chitosan and oxygen atoms on Fe3O4 (1 1 1) surface is more than that of Fe3O4 (1 1 0) surface, and the nitrogen atoms and iron atoms on the surface have weak physical interactions. This study provides useful information in understanding the interfacial interaction mechanism at the atomistic scale for polymer and mineral. (C) 2012 Elsevier B.V. All rights reserved.