Biomedical Engineering Reference
In-Depth Information
Figure 9.21
Schematic of the LB nanocomposite film used in the
experiments with SWCNTs bundles as filler and the molecular
structure of CdA as the host matrix. This figure is reprinted
and adapted with permission from IOP [186].
The HiPco as-grown SWCNTs (AG-SWCNTs) were purified in a
two-step process: oxidized at 300°C in oxygen for 1 h (OX-SWCNTs),
and oxidized SWCNTs post-treated in 37% HCl acid at room
temperature for 48 h (OA-SWCNTs). The raw and purified SWCNTs
were used as filler in the LB film nanocomposite for SAW gas sensing
applications. HR-TEM images and SEM images of the pristine and
purified SWCNTs are shown in the Fig. 9.22. TEM observations
reveal the nanosize structure of HiPco nanotubes with a diameter
of about 2 nm and a variety of structural defects at the sidewalls
and nanocaps of the nanotubules. Metal particles of the Fe catalyst
are identified as dark particles. Additionally, SEM images compare
the LB 75 wt.% nanocomposite 10-monolayer film with raw and
purified SWCNTs as filler in the CdA host matrix. The composite
forms a nanonetwork of bundles of individual nanotubules covered
by the CdA-matrix layer with a different density of aggregation. This
sponge-like distribution of the LB nanocomposite with various raw
and purified CNTs promotes high vapor adsorption capability.
