5 - Graphene-based polymer coatings

Abstract

Graphene, known as honeycomb carbon, is the building block of the allotropes of carbon and its rearrangement into various geometries results in different materials such as graphite, nanotubes, and fullerenes. It is composed of a flat sheet of carbon atoms arranged in a hexagonal lattice on a 2D plane. Therefore, it is known as honeycomb carbon. The outstanding properties of this crystal honeycomb carbon are very interesting and novel to the scientific world. Polymer coatings are used in almost all applications in the current era due to their versatile nature and exceptionally good properties such as improving the functional stability of materials and imparting protection to various surfaces. Organic coatings have been used for decades for their cost-effectiveness and industrial applicability with several benefits. At the same time, the polymer matrix is found to possess poor barrier properties and cannot remain functional for a longer duration, which hinders its long-term service. Hence, in this regard, some filler materials need to be added to the polymer matrix to make these synthesized coatings more functional, durable, and performance-oriented. This unique combination of polymers and nanoscale filler materials contributes significantly toward the enhancement of physical, chemical, and mechanical properties of the nanocomposite. These nano-reinforced polymer coatings can be synthesized from a variety of filler materials such as talc, glass fibers, carbon black, layered silicates, and calcium carbonate, to name but a few. Out of these, the carbon-based nanofillers such as carbon nanotubes and graphene nanosheets provided better physico-mechanical properties on account of their high aspect ratio and surface area. Having said that, the miscibility of these nonfillers within the polymer matrix is a matter of concern, and the ability of graphene and its derivatives to disperse within a variety of polymers has expanded the horizon of developing a new class of graphene-based polymer nanocomposite coatings. This work focuses on the detailed analysis of the recent literature on graphene-derived nanocomposite coatings, synthesis methods, and characterization techniques involved to give a broader idea to the scientific community targeting the coatings and allied fields of application. Before discussing the prior art available on the types of graphene-based coatings, it is mandatory to understand the difference between graphene and its derivatives.