Shortened single-walled nanotubes functionalized with poly(ethylene glycol): preparation and properties

Abstract

Poly(ethylene glycol) (PEG) was grafted to shortened single-walled carbon nanotubes (shSWNTs) obtained from original SWNTs after acid oxidative cutting and etching processes. PEGsh-SWNTs, prepared by treating the sh-SWNTs with SOCl 2 followed by amidation with PEGmonoamine (molecular weight = 2000), are moderately soluble in tetrahydrofuran, chlorinated hydrocarbons (ca. 1 mg/ml), sparingly soluble in water, acetone CH 3 OH and insoluble in non polar solvents such as toluene, hexanes or carbon disulfide. Non linear transmission measurements on solutions of PEG-sh-SWNTs in CHCl 3 showed a better optical limiting performance relative to that recorded for original SWNTs suspended in the same solvent.

Nonlinear Optical Materials for the Smart Filtering of Optical Radiation

“…The nonlinear transmission of poly­(ethylene glycol) connected to shortened SWNTs (PEG-sh-SWNTs) in solution was compared to that of a suspension of pure SWNTs in CHCl 3 using 9 ns pulses at 532 nm from Nd:YAG laser . Differently from the behavior of non derivatized soluble nanotubes, PEG-sh-SWNTs showed better OL response than that of pure SWNTs.…”

Carbon nanotubes and organic solar cells

“…Higher solubilities are often reached by the classic oxidation of the CNT walls with either nitric acid or sulphonitric mixture followed by etching with hydrogen peroxide, conversion of carboxylic groups into acyl chlorides and reaction with nucleophiles (e.g., amino-polyethylene glycol (PEG)). 113 A different chemical approach, the selective degradation, 108 is based on the annihilation of the properties of undesired electronically active carbon materials through oxidation with oxygen, fluorine and hydrogen peroxide. Somehow analogous to this strategy, the selective exfoliation of the outer walls of MWNTs has been induced by applying electric currents with densities exceeding 10 9 A cm À2 and it is referred to as electrical breakdown.…”

“…139 Proper chain structures can effectively help to disentangle CNTs in order to achieve solubility and to improve the dispersion in polymer matrices. 34,113,140,141 In some cases, disentanglement was so effective that phonon dynamics could be clearly observed in real-time through femtosecondresolved pump-probe experiments. 35 This kind of functionalization provides efficient disaggregation of CNT bundles and is particularly attractive for BHJ applications.…”

Preparation and characterisation of polyurethane grafted single-walled carbon nanotubes and derived polyurethane nanocomposites

“…The grafting reactions include in-situ radical polymerization, [12][13][14][15] living anionic polymerization, 16 polycondensation 17 and direct attachment to the functional polymer. [18][19][20][21] Generally it starts from the functional groups such as -COOH or -OH on the sidewalls of the carbon nanotubes, which are derived from the oxidation of the carbon nanotubes.…”