Mechanical and Barrier Properties of Functionalized Carbon Nanostructures

0D, 1D, and 3D carbon allotropes have attracted attention from diverse applications because of their inimitable characteristics such as excellent physical, thermal, and chemical stabilities, high elastic modulus, high ultraviolet (UV) absorption, and extraordinary hybridized sp2/sp3 carbonaceous structure. The superhydrophobic nature of carbon nanomaterials (CNMs) such as graphene, carbon nanotubes (CNTs), and fullerene is the main drawback in the application of CNMs as fillers in polymers. The multifunctional performance of CNMs-reinforced polymer nanocomposites such as mechanical and barrier properties can be boosted by the surface modification of CNMs. The higher chemical compatibilities and better dispersion/distribution of the CNMs in polymers after the surface modification account for the better barrier properties and a more efficient transition of stresses from a polymer matrix to carbonaceous nanofillers. The present chapter aims to discuss the concepts of the functionalization of CNMs, followed by the recent progress on the functionalized CNMs-enhanced polymer nanocomposites with superior mechanical and barrier properties.