*2.2. Thermogravimetric Analysis*

TGA is a useful technique for studying the weight change of samples with increasing temperature. The degradation temperature (Td) is the temperature corresponding to the maximum rate of weight loss at each stage. The peak of Td can be clearly observed from the first derivative of the TGA curve with respect to temperature, called derivative thermogravimetry (DTG). As shown in Figure 4A, the weight of CS NPs and CS@CBLO NPs decreased as the temperature increased from 25 to 600 ◦C. The CS NPs showed two stages of weight loss (Figure 4A-i,B-i). The first and second stages of the weight loss of CS NPs were at temperature range of 31 to 114 ◦C and 171 to 293 ◦C, corresponding to water evaporation and chitosan decomposition, respectively. However, CS@CBLO NPs showed three stages of weight loss (Figure 4A-ii–vi,B-ii–vi). Compared to the TGA/DTG of CS NPs (Figure 4A-i,B-i), the third stage weight loss of CS@CBLO NPs in a temperature range of 293 to 415 ◦C was caused by CBLO decomposition. From the DTG thermograms, CS NPs exhibited two-stage degradation, at 65 ◦C and 250 ◦C, respectively (Figure 4B-i). However, the CS@CBLO NPs showed new Td at 368 ◦C (Figure 4B-ii–vi), corresponding to the Td of CBLO. The results confirmed that the encapsulation of CBLO into CS@CBLO NPs was successful.

**Figure 4.** (**A**) TGA and (**B**) DTG thermograms of (**i**) CS NPs and (**ii**)–(**vi**) CS@CBLO NPs prepared using different weight ratios of CBLO to chitosan of (**ii**) 0.25:1, (**iii**) 0.50:1, (**iv**) 0.75:1, (**v**) 1.00:1, and (**vi**) 1.25:1.
