Covalent modification of vapour-grown carbon nanofibers via direct Friedel–Crafts acylation in polyphosphoric acid

Abstract

Electrophilic functionalization of vapour-grown carbon nanofibers (VGCNF) was accomplished via FriedelCrafts acylation with 2,4,6-trimethylphenoxybenzoic acid in polyphosphoric acid using the improved conditions that we previously described. The progress of the reaction was conveniently monitored with FT-IR spectroscopy following the growth of the keto-carbonyl band at 1664 cm 21 associated with the product. In addition to scanning electron microscopic and UV-vis spectroscopic data, the combined results from the elemental analysis and thermogravimetric analysis further suggested that there were 3 arylcarbonyl groups covalently attached to the nanotube structure for every 100 carbon sites. Because of the presence of significant hydrogen content in the starting VGCNF, the covalent attachment of the arylcarbonyl groups most probably occurred at the sp 2 C-H sites.

Simplified tube form factor for analysis of small-angle scattering data from carbon nanotube filled systems

“…The fractal rod and fractal-tube form factors account for the long-range correlations although the fractal rod still cannot sufficiently fit the data. SEM images, (a) and (b), of the MER MWCNTs functionalized similarly to previous work (Baek et al, 2004) and used in the composites. The diameters of the nanotubes after functionalization are~800 Å , which validates the dimensions obtained from USAXS using the STFF and the fractal-tube form factor.…”

“…The desired quantity of MWCNTs [catalytically grown MWCNTs (>90% pure); MER Corporation] were functionalized as previously reported (Baek et al, 2004) and mixed with the appropriate quantity of Matrimid 5292B [o,o 0 -diallyl bisphenol A; Huntsman Advanced Materials (Europe)] using an Ultra-Turrax T25 homogenizer (300 rev s À1 , 423 K, 3 h). The MWCNTs/Matrimid 5292B was then sonicated in an ethylene glycol bath (80 kHz/150 W, 373 K, 4 h).…”

Mild and Nondestructive Chemical Modification of Carbon Nanotubes (CNTs): Direct Friedel-Crafts Acylation Reaction

“…In addition to CNTs, the covalent modification method of direct Freidel-Crafts acylation reaction in a mild PPA/P 2 O 5 medium can be expanded to other carbon-based nanomaterials such as fullerene (C 60 ) [14], carbon nanofiber [7,[15][16][17] and graphene [19][20][21][22]. Buckminster fullerene, C 60 , which is of the most abundant carbon sphere, is generally considered as a stable electron deficient material.…”

“…Since the pioneering work from Baek et al, [7], direct Friedel-Crafts acylation reaction to inherent defective sp 2 C-H sites on the surface of CNTs have been widely investigated [8][9][10][11][12][13], because it has several advantages such as nondestructive reaction nature, sufficient modification level, utilization of diverse materials and suitable for mass production. Furthermore, it can be expanded to all types of carbon-based nanomaterials such as fullerenes [14], carbon nanosfibers [7,[15][16][17], nanodiamonds [18] and graphene [19][20][21][22].…”

“…Furthermore, it can be expanded to all types of carbon-based nanomaterials such as fullerenes [14], carbon nanosfibers [7,[15][16][17], nanodiamonds [18] and graphene [19][20][21][22]. Therefore, direct FriedelCrafts acylation reactions could be one of ideal chemical modifications for carbon based materials, specifically CNTs.…”