Dispersibility of vapor phase oxygen and nitrogen functionalized multi-walled carbon nanotubes in various organic solvents

Abstract

The synthesis and characterization of gas phase oxygen- and nitrogen-functionalized multi-walled carbon nanotubes (OMWCNTs and NMWCNTs) and the dispersibility of these tubes in organic solvents were investigated. Recently, carbon nanotubes have shown supreme capacity to effectively enhance the efficiency of organic solar cells (OSCs). A critical challenge is to individualize tubes from their bundles in order to provide homogenous nano-domains in the active layer of OSCs. OMWCNTs and NMWCNTs were synthesized via HNO3 vapor and NH3 treatments, respectively. Surface functional groups and the structure of the tubes were analyzed by temperature-programmed desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, and Raman spectroscopy which confirmed the formation of functional groups on the tube surface and the enhancement of surface defects. Elemental analysis demonstrated that the oxygen and nitrogen content increased with increasing treatment time of the multi-walled carbon nanotube (MWCNT) in HNO3 vapor. According to ultra-violet visible spectroscopy, modification of the MWCNT increased the extinction coefficients of the tubes owing to enhanced compatibility of the functionalized tubes with organic matrices.

Influence of defects induced by chemical treatment on the electrical and thermal conductivity of nanofluids containing carboxyl-functionalized multi-walled carbon nanotubes

“…This has been reported and discussed in several reports. 40,41 As the chemical treatment time increased to 5 hours, besides defects observed at outside walls, some defects starting appeared on the inside walls of the MWCNTs as broken points ( Fig. 2e and f).…”

Synthesis of Phosphonated Carbon Nanotubes: New Insight into Carbon Nanotubes Functionalization

“…However, large area imaging presented a higher purity of functionalized samples in terms of a lower presence of amorphous carbon. It is frequently reported, that nanotubes are purified during a functionalization reaction and washing after synthesis [ 58 , 59 ].…”

Effect of nitrogen and oxygen doped carbon nanotubes on flammability of epoxy nanocomposites

“…Moreover, among the doped nanotubes, CO x presents the highest weight reduction rate at the lowest temperature reflecting that this kind of nano-tubes are much more reactive than CNT or CN x ; intuitively, the surface roughness and the surface functionalities of these tubes may contribute to increase its reactivity. However, these doped nanotubes are more thermally stable than oxygen and nitrogen functionalized nanotubes obtained by chemical treatments of pristine CNT either in solution or in gas phase [37].…”