Polymer Grafting to Single‐Walled Carbon Nanotubes: Effect of Chain Length on Solubility, Graft Density and Mechanical Properties of Macroscopic Structures

Abstract

Single-walled carbon nanotubes are grafted with polystyrene chains employing a graft-to protocol. Thermogravimetric analysis allows calculation of the grafted chain density and average interchain separation on the nanotube surface as a function of molecular weight. The separation scales with molecular weight as a power law with an exponent of ca. 0.588, showing the grafted chains to be in a swollen random walk conformation. This implies that chain packing is controlled by coil size in solution. In addition, the dispersed concentration of functionalized nanotubes scales with the size of the steric potential barrier that prevents aggregation of polymer functionalized nanotubes. It is also shown that the molecular weight of the grafted chains significantly affects the mechanical properties of nanotube films.

Enhanced interfacial thermal transport across graphene–polymer interfaces by grafting polymer chains

“…The grafting density was defined as r = N/A, where N is the number of PE chains, and A is the surface area of graphene monolayer [20]. Three grafting densities (r = 0.0032, 0.0064, and 0.0144 Å À2 ) were used.…”

Click Functionalization of a Dibenzocyclooctyne‐Containing Conjugated Polyimine

“…Initially we used polystyrene azides with molecular weights of 4, 9, and 24 kDa ( Table 2). [66,67] Polymer P0 was stirred with 1.5 equivalents of azide-terminated polymer (per alkyne) at 60 8 8Cf or 12 hours in deuterated toluene.A lkyne conversion was found to be quantitative,even when employing 24 kDa polystyrene grafts,a sR aman and 1 H-NMR spectroscopy showed no evidence of residual alkyne in the high-molecular-weight products (Figure 3a,b,and Table 2).…”

Click Functionalization of a Dibenzocyclooctyne‐Containing Conjugated Polyimine

“…To further test the cycloaddition, we performed a series of reactions with azide‐terminated polymers (Scheme , P6 – P10 ). Initially we used polystyrene azides with molecular weights of 4, 9, and 24 kDa (Table ) . Polymer P0 was stirred with 1.5 equivalents of azide‐terminated polymer (per alkyne) at 60 °C for 12 hours in deuterated toluene.…”