Fig. 4

Structural characterization of different BC samples. a FT-IR ATR spectra of HC-6CF-BC (black), LC-6CF-BC (red) and BC (blue), showing a structural modification. New peaks appeared at 1530 cm⁻¹ and 1650 cm⁻¹ in the spectra of HC-6CF-BC and LC-6CF-BC, demonstrating the successful introduction of 6CF into BC. b XRD spectra of HC-6CF-BC (black), LC-6CF-BC (red) and BC (blue), showing changes in crystallinity. c TG and d DTG analysis of HC-6CF-BC (black), LC-6CF-BC (red) and BC (blue). The lowest endothermic peak of HC-6CF-BC (black) and LC-6CF-BC (red) was 330 °C and 335 °C, respectively, and the peak was 365 °C for BC (blue). The crystallization temperature of 6CF-BC was lower than BC by 30–35 °C, indicating an increase in the amorphous cellulose content in 6CF-BC