The crystallinity (χc), which was calculated based on the
crystalline and amorphous intensity of cellulose aerogels, is
calculated following the method in ref 60. It was found that the
crystallinity has a slight decrease (Table 3). Nevertheless, the crystallite size of reflection (L200) and the interlayer distance
(d200) of BCA and HBCAs of these cellulose aerogel samples
did not show obvious variation after the trimethylsilylation
(Table 3). This may be because the modifier (TMCS) on the
surface of cellulose nanofibers enhanced the proportion of
amorphous phase, while the trimethylsilylation did not destroy
the crystal structure of bacterial cellulose. The increase of
amorphous phase did not damage the crystalline phase, which
can further suggest that the trimethylsilylation of BCA with
TMCS occurred essentially only on the surface of the cellulose
nanofibers.
Thermal Degradation Behavior. The TGA and DTG
curves of BCA and the HBCAs are shown in Figure 6.
Compared with the original cellulose aerogel, the TGA curves