Production of graphene composite by direct graphite exfoliation with chitosan

We propose a technique of direct exfoliation of graphite with chitosan (CS) allowing to obtain graphene flakes in a polymer matrix. During the process chitosan macromolecules were converted into soluble forms by the addition of the acetic acid (Ac) and the asparagine acid (Asp). The acid selection was proven to have an influence on the electrical and the morphological properties of graphene-chitosan composites. The electrical resistance is changing by factor 2 depending on used acid. Graphene sheets obtained in both processes were shown to have low amount of defects. The new composite may have wide range of potential applications, e.g. for conducting composites, optoelectronic, and in biological or medical research. (C) 2014 Elsevier B.V. All rights reserved.