DATA: THE NEW CORPORATE RESOURCE - Carbon Nanotubes: From Bench Chemistry to Promising Biomedical Applications - page 11

Figure 1.6 Schematic representation of the mechanism of encapsulation of SWCNTs
into block copolymers. Reproduced from Kang et al. 29 with permission. See also Colour
Insert.
peaks of the protons next to the amino groups are shifted downield.
Furthermore, thermogravimetric analysis (TGA) data showed that 26%
wt of the complex was formed by the polymer; it was also found that the
grafting procedure reached saturation when the polymer was employed at a
concentration of ~10 mg/mL. In saturation condition, the complex presented
an excess of free amino groups (NH 2 /COOH = 1.4). 30
Xu et al. 31 created a novel biocompatible block copolymer, cholesterol-
end-capped-poly(2-methacryloyloxyethyl phosphorylcholine) (CPMPC)
that formed complexes with MWCNTs by simple mixing and brief
sonication (30 s); this polymer showed great eficacy in individually
suspending MWCNTs in water up to concentrations of 3.307 mg/mL
(Fig. 1.7). 17
Figure 1.7 TEM images of (a) pristine CNTs and (b) CPMPC-coated CNTs. The images
show the effective isolation of individual nanotubes by the formation of CNT-block
copolymer complexes. Reproduced from Xu et al. 17 with permission.
The use of block copolymers in the stabilisation of aqueous suspensions
of CNTs has so far been demonstrated to be a very promising approach to the
preparation of CNT-polymer complexes with stability and biocompatibility
characteristics that will allow their use in vivo . This is a very promising
advance towards the development of novel systems for drug delivery, gene
transfection, in vivo imaging and targeted thermoablation. 24 The major