Physicochemical Characterization of Acid-Treated Nanocrystal Cellulose and Amorphous Cellulose from Bamboo Sawdust

Figures & data

Figure 1. The flowchart of the purification and extraction process for bamboo nanocrystal cellulose (BBF-NCC) and bamboo amorphous cellulose (BBF-AC).

Figure 2. Photograph images of: (a) BBF-R, (b) BBF-A, (c) BBF-B (after 1^st bleaching), (d) BBF-B (after 6^th bleaching).

Figure 3. The SEM images of: (a) BBF-R, (b) BBF-A, (c) BBF-B (after sixth bleaching).

Figure 4. TEM images of: (a), (b) BBF-NCC, (c), (d), (e) BBF-AC.

Figure 5. The dimension, length and aspect ratio of BBF-NCC: (a) diameter, (b) length, (c) aspect ratio.

Figure 6. The aqueous suspensions of: (a) BBF-NCC under normal light, (b) BBF-NCC under cross-polarized light setup, (c) BBF-AC.

Figure 7. The FTIR spectra of: (a) BBF-R, (b) BBF-A, (c) BBF-B, (d) BBF-AC, (e) BBF-NCC.

Table 1. Assignments of characteristic FTIR absorption bands of the bamboo fibers.

Functional group	Assignment	Wavenumber (cm^−1)
		BBF-R	BBF-A	BBF-B
C=O stretching in unconjugated ketones aldehydes and carboxyl	hemicellulose	1725	-	-
C=C stretching of the aromatic ring	Lignin	1602	1592	-
C=C stretching of the aromatic ring	Lignin	1512	1509	-
Asymmetric bending in CH3	Lignin	1453	1455	-
CH2 bending	Cellulose	1421	1422	1425
CH bending	Cellulose	1367	1367	1366
CH2 wagging	Cellulose	1316	1316	1314
CO stretching	Lignin and hemicellulose	1262	-	-
COC asym. bridge oxygen stretching	Cellulose	1159	1158	1158
asym. Out of phase ring stretching	Cellulose	895	896	895

Figure 8. The NMR spectra of: (a) BBF-R, (b) BBF-B, (c) BBF-NCC, (d) BBF-AC.

Figure 9. The XRD spectra of: (a) BBF-B, (b) BBF-NCC, (c) BBF-AC.

Table 2. Zeta potential and size of BBF-B, BBF-NCC, and BBF-AC.

Sample	zeta potential (mV)
BBF-B	−9.53
BBF-AC	−19.73
BBF-NCC	−30.93