Threading through Macrocycles Enhances the Performance of Carbon Nanotubes as Polymer Fillers

Abstract

In this work, we study the reinforcement of polymers by mechanically interlocked derivatives of single-walled carbon nanotubes (SWNTs). We compare the mechanical properties of fibers made of polymers and of composites with pristine SWNTs, mechanically interlocked derivatives of SWNTs (MINTs), and the corresponding supramolecular models. Improvements of both Young’s modulus and tensile strength of up to 200% were observed for the polystyrene–MINT samples with an optimized loading of just 0.01 wt %, while the supramolecular models with identical chemical composition and loading showed negligible or even detrimental influence. This behavior is found for three different types of SWNTs and two types of macrocycles. Molecular dynamics simulations show that the polymer adopts an elongated conformation parallel to the SWNT when interacting with MINT fillers, irrespective of the macrocycle chemical nature, whereas a more globular structure is taken upon facing with either pristine SWNTs or supramolecular models. The MINT composite architecture thus leads to a more efficient exploitation of the axial properties of the SWNTs and of the polymer chain at the interface, in agreement with experimental results. Our findings demonstrate that the mechanical bond imparts distinctive advantageous properties to SWNT derivatives as polymer fillers.

Bimodal supramolecular functionalization of carbon nanotubes triggered by covalent bond formation

“…Our results illustrate how the combination of covalent and noncovalent chemistries opens the door to novel types of functionalization of SWNTs in which the degree of functionalization, the electronic interaction between the nanotubes and their supramolecular partners, and, most remarkably, their topology 51 can be varied.…”

Controlled Covalent Functionalization of 2 H‐MoS2 with Molecular or Polymeric Adlayers

“…Furthermore, 1 H NMR (400 MHz) experiments confirmed the disappearance of the alkene signals, and the appearance of signals at 4.61 and 4.40 ppm, that can be attributed to the new aliphatic protons. Moreover, all signals appear broadened, which is characteristic of the formation of high‐molecular weight species (see Figure S16) …”

Putting Rings around Carbon Nanotubes

“…In collaboration with Dario Pisignano and Juan J. Vilatela, we have recently shown that the encapsulationo fS WNTst of orm MINTsr esultsi ns ignificant improvements in the reinforcement of electrospun polystyrene (PS) fibers. [70] In fact, the Young's moduli and tensile strength were enhanced up to 200 %i nt he PS-MINTs amples, withj ust 0.01 wt %o fM INTs. More importantly,supramolecular modelswith identicalchemical composition and loading had no effect, or even weakenedt he final fibers.…”