Polymer Nanocomposites-A Comparison between Carbon Nanotubes, Graphene, and Clay as Nanofillers

Abstract

Nanofilled polymeric matrices have demonstrated remarkable mechanical, electrical, and thermal properties. In this article we review the processing of carbon nanotube, graphene, and clay montmorillonite platelet as potential nanofillers to form nanocomposites. The various functionalization techniques of modifying the nanofillers to enable interaction with polymers are summarized. The importance of filler dispersion in the polymeric matrix is highlighted. Finally, the challenges and future outlook for nanofilled polymeric composites are presented.

Keywords: carbon nanotubes; graphene, clay; polymer nanocomposites; properties.

Figure 1

Graphene is a 2D building material for carbon materials of such as 0D buckyballs, 1D nanotubes or 3D graphite. Reproduced from Reference [13] with permission.

Figure 2

Structure of montmorillonite. Reproduced from reference [5] with permission.

Figure 3

Schematic representation of different types of composite; (a) conventional composite; (b) intercalated composite; and (c) exfoliated composite. (Reproduced from reference [101], with permission).

Figure 4

Schematic of basic electrospinning set-up with SEM image of nonwoven mat of poly(vinylpyyrolidone) nanofiber deposited on the collector (From Reference [187] with permission).

Figure 5

A negatively charged substrate is immersed in the solution of positively charged polyelectrolyte. The latter forms a submonolayer on the surface of the substrate, which switches the surface charge to positive. After rinsing with water, it is then immersed in the dispersion of negatively charged polyelectrolyte or nanoparticles. This results in the formation of a new layer, which switches the surface charge to negative. The whole cycle can be repeated as many times as is desired.