Civil Engineering Reference
In-Depth Information
sulfate groups at the surface of CNC, which play a l ame retardant role and lead to
decreased degradation temperature.
11.4.3
Morphological Properties
h e atomic force microscopic (AFM) test is good for analyzing and evaluating the sur-
face characteristic of nanocellulose. Normally, at er preparation of nanocellulose sus-
pension, a drop of this suspension is deposited onto cleaved mica, dried, and then the
image is recorded at room temperature and in tapping mode [139]. Figure 11.16 shows
the AFM image of NFC from sot wood [64] and CNC from MCC [140].
h e AFM image (Figure 11.16a) exhibits a network structure, interconnected, entan-
gled and in coiled form with width of 20 to 30 nm. As the AFM picture of CNC (Figure
11.16b) displays, very low agglomeration occurred and the diameter of CNC was lower
than 10 nm.
h e dimension and structure of the nanocellulose can be studied using transmission
electron microscopy (TEM). Generally, a drop of diluted nanocellulose suspension is
deposited on carbon-coated grid and is dried at room temperature. Size measurements
can be done by image analyzer program [3]. Figure 11.17 illustrates the TEM image of
CNC from tunicate using H
2
SO
4
acid hydrolysis [115] and NFC from potato pulp [141].
Figure 11.16
AFM images of
(a)
NFC from sot wood pulp [64] and
(b)
CNC from microcrystalline
cellulose [140] .
Figure 11.17
TEM image of
(a)
CNC from tunicate [115] and
(b)
NFC from potato pulp [141].
