Functionalization of single-walled carbon nanotubes with well-defined polystyrene by "click" coupling.
Covalent functionalization of alkyne-decorated SWNTs with well-defined, azide-terminated polystyrene polymers was accomplished by the Cu(I)-catalyzed [3 + 2] Huisgen cycloaddition. This reaction was found to be extremely efficient in producing organosoluble polymer-nanotube conjugates, even at relatively low reaction temperatures (60 degrees C) and short reaction times (24 h). The reaction was found to be most effective when a CuI catalyst was employed in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene as an additive. IR spectroscopy was utilized to follow the introduction and consumption of alkyne groups on the SWNTs, and Raman spectroscopy evidenced the conversion of a high proportion of sp(2) carbons to sp(3) hybridization during alkyne introduction. Thermogravimetric analysis indicated that the polymer-functionalized SWNTs consisted of 45% polymer, amounting to approximately one polymer chain for every 200-700 carbons of the nanotubes, depending on polymer molecular weight. Transmission electron microscopy and atomic force microscopy were utilized to image polymer-functionalized SWNTs, showing relatively uniform polymer coatings present on the surface of individual, debundled nanotubes.
Li
Huaming
H
Department of Chemistry and Brockhouse Institute for Materials Research (BIMR), McMaster University, Hamilton, Ontario L8S 4M1, Canada.
Cheng
Fuyong
F
Duft
Andy M
AM
Adronov
Alex
A
D015394:Molecular Structure; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
D037742:Nanotubes, Carbon; D011137:Polystyrenes