Modifying the Electronic Character of Single-Walled Carbon Nanotubes Through Anisotropic Polymer Interaction: A Raman Study

Abstract

Using Raman spectroscopy, we demonstrate that the anisotropic interaction between single‐walled carbon nanotubes (SWNTs) and poly(methyl methacrylate) (PMMA) causes significant changes in the electronic properties of their composites. Two different procedures were used to prepare the composites: melt blending and in‐situ UV polymerization. Resonant Raman studies relate the electronic density of states (DOS) of the SWNTs to the corresponding vibration symmetry changes of both the PMMA and the SWNTs. Our results show that, in the melt‐blended sample, the SWNTs—originally semiconducting—became predominantly metallic. The changes in the electronic properties were also confirmed by dielectric constant measurements. We propose that the anisotropic interaction between PMMA and SWNTs in the melt‐blended composite is the dominant reason for the observed electronic character change.

Influence of graphene oxide on thermal, electrical, and morphological properties of new achiral polyimide

“…This indicates that the number of sp 3 ‐bonded carbons increased may due to the bond formation between PI and GO during in situ polymerization. The observed results are consistent with the earlier carbon based reports .…”

Synthesis of highly-stretchable graphene – poly(glycerol sebacate) elastomeric nanocomposites piezoresistive sensors for human motion detection applications

“…Moreover, it was observed that the peak related to the D-band broadened with the increase of the graphene flakes incorporated into the PGS solution before cross-linking, which suggests the formation of covalent bonds between the PGS polymer chains and the graphene flakes. Chen et al [28] observed that the D-band peak of carbon nanotubes broadened during in-situ polymerization of poly(methyl methacrylate) (PMMA), and attributed this phenomenon to covalent bonding between the PMMA chains and the CNT's. Differential scanning calorimetry (DSC) performed on the pristine and nanocomposite PGS samples showed that the polymer had a glass transition around -10 °C, followed by a melting transition with maxima at ~8 °C (figure 4b).…”

Modification and Grafting of Multi‐Walled Carbon Nanotubes with Bisphenol‐A‐polycarbonate

“…Nanocomposites from MWNTs1, 2 with polymers have been reported to improve mechanical strength, electrical and thermal conductivity and thermal stability. A number of papers appeared which deal with processing and characterization of nano‐composites based on CNTs in different polymer matrices, such as epoxy,3–5 nylon,6–9 polycarbonate (PC),10–12 poly(methyl methacrylate) (PMMA)13–15 and polystyrene (PS) 16–19…”