Free-standing paper-like or foil-like materials based on modifications of elemental carbon draw a great attention over the last years. Their proposed or already implemented uses include protective layers, chemical filters, components of electrical batteries or supercapacitors, adhesive layers, electronic or optoelectronic components, and molecular storage. Similarly to buckypapers prepared from carbon nanotubes by vacuum filtration, a free-standing membrane can be made by a flow-directed assembly of individual graphene or graphene oxide sheets.This new material outperforms many other paper-like materials in stiffness and strength. Its combination of macroscopic flexibility and stiffness is a result of a unique interlocking-tile arrangement of the nanoscale sheets.

Graphene is a two-dimensional crystal, consisting of hexagonally-arranged covalently bonded carbon atoms and is the template for one dimensional CNTs, three dimensional graphite, and also of important commercial products, such as polycrystalline carbon fibres (CF). As a single, virtually defect-free crystal, graphene is predicted to have an intrinsic tensile strength higher than any other known materials and tensile stiffness similar to graphite. In graphitic materials, such as CF, the variation of phonon frequency per unit of strain can provide information on the efficiency of stress transfer to individual bonds. Indeed, the higher the crystallinity of a fibre (and hence the modulus) the higher the degree of bond deformation and, hence, the higher the measured Raman shift per unit strain.

The classic methods for low volume fraction polymer nanocomposites based on CNTs involve melt blending, solution casting, solution mixing, direct mixing and in-situ polymerization. However, using these techniques has resulted in phase separation between polymer and CNTs, low polymer wetting of CNTs and low interfacial shear strength between polymer matrix and CNTs.

Carbon nanotubes (CNTs) have attracted great interest because of their unique mechanical and electronic properties. They show a very high aspect ratio (length-to-diameter) and they have been shown to participate in applications such as in sensing, nanoelectronics and mechanical reinforcement of various matrices. However, manipulation and processing of CNTs has been limited by their insolubility in most common solvents, although some dissolution has recently been obtained.