3.1.3. TGA

The thermal stabilities of the Bi-MIPs, Bi-NIPs, Si-MIPs and Si-NIPs were studied by TGA analysis, and the results are presented in Figure 3b,c. As shown in Figure 3b, the thermogravimetric analysis curves of the Bi-NIPs, Si-MIPs and Si-NIPs are the same as those of the Bi-MIPs without significant difference. The Bi-MIPs start to decompose at 220 ◦C, the temperature of the fastest decomposition rate occurs at 404 ◦C and the maximum decomposition temperature (Tmax) is 468 ◦C. The decomposition process is divided into two stages, including dehydration in the low-temperature zone (100–220 ◦C) and decomposition in the high-temperature zone (404–462 ◦C). The decomposition of the second stage is due to the decomposition of the crosslinker (EGDMA), indicating that the stability of the crosslinker is the main factor affecting the thermal stability of the polymers. The TGA results demonstrate that the Bi-MIPs have excellent thermal stability.

**Figure 2.** SEM, average particle size and particle size distribution images of Bi-MIPs (**a**,**b**), Bi-NIPs (**c**,**d**), Si-MIPs (**e**,**f**) and Si-NIPs (**g**,**h**).

**Figure 3.** (**a**) FI-IR images of the Bi-MIPs, Bi-NIPs, Si-MIPs and Si-NIPs; (**b**) TGA images of the Bi-MIPs, Bi-NIPs, Si-MIPs and Si-NIPs; (**c**) TGA and DTG images of the Bi-MIPs.
