The dimensions of CNCs were further elucidated by AFM of
air-dried highly diluted suspensions (0.001, w/w%) deposited on
freshly cleaved mica surfaces (Fig. 4). AFM phase images collected
under the tapping mode showed typical distributions of both CNC
30 (Fig. 4a) and CNC45 (Fig. 4e) with the latter being more numerous
as expected from its much smaller dimensions at a similar
concentration. The height profiles of both CNCs (Fig. 4c and g) are
similar, ranging from 1 to 11 nm, with mean heights of 5.95 nm
(34%CV) (Fig. 4d) and 5.06 nm (34%CV) (Fig. 4 h) for CNC30 and
CNC45, respectively. The much smaller thickness than their corresponding
widths of 30.7 and 11.1 nm, showed these CNCs to be
flat at 5:1 and 2:1 width-to-thickness ratio for CNC30 and CNC45,