Fabrication of multilayer films from regenerated cellulose and graphene oxide through layer-by-layer assembly

A key challenge in the preparation of nanoplatelet-filled polymer composites is the ability to realize the nanometer-level dispersion and the planar orientation of nanosheets in polymer matrices. In this report, multilayer films were successfully fabricated by layer-by-layer assembly of regenerated cellulose and graphene oxide, in which graphene oxide nanosheets were used as the building blocks. The thickness of 50 layer film is about 20 μm and it exhibits a high degree of smoothness. This may be attributed to the well-defined layered structure with high degree of planar orientation and nanolevel assemblies of graphene oxide nanosheets in the polymer matrices. Typical field emission scanning electron microscope images demonstrate an ordered arrangement of layers. The electrical conductivity of the multilayer films shows a remarkable increase with increasing layer of the films. A significant enhancement of mechanical properties has been achieved, that is, a 110.8% improvement of elastic modulus and a 262.5% increase of hardness respectively.