## 3 Results and Discussion  
### Investigation of Structure and Composition for Composite Beads  
The spectra were recorded comparatively for the composite beads with RM content (1-RM \(\div\) 3-RM) vs. the reference counterparts (1-Ref \(\div\) 3-Ref) and the precursor materials (copolymers and RM alone) to determine the effect of the addition of RM on the chemical structure and composition and the importance of the copolymer/RM ration in the composite beads (Figure 2A-C). In the area of low wavelengths, the signals corresponded to the sulfate ions from the redox initiation system, with symmetric stretch \(\sim\)950 cm\({}^{-1}\)[73] (for beads and copolymers) and stretching of S=O from DMSO around 1030 cm\({}^{-1}\) (beads) [74], and overlapped with the signals in RM corresponding to the Si-O-Al bonds (\(\sim\)1000 cm\({}^{-1}\)) in all the spectra of composite beads (1-RM, 2-RM, and 3-RM). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample** & **TOC (mg/L)** & **TOC (mg/L)** \\
**Code** & **1 st Step** & **2 nd Step** \\ \hline
1-REF & **8.99** & 1.76 \\
1-RM & **14.55** & 1.28 \\
2-REF & 1.21 & - \\
2-RM & 1.84 & - \\
3-REF & 0.71 & - \\
3-RM & 1.78 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Total organic carbon (TOC) in the supernatants resulting from the washing procedure of copolymer beads. Figure 2A shows the FTIR spectra for the series 1-RM and 1-Ref, which reveals the characteristic bands of the copolymer at 3386 cm\({}^{-1}\) and 1730 cm\({}^{-1}\) (stretching O-H and C=O, respectively, from the -COOH group of AA), 2243 cm\({}^{-1}\) (stretching C\(\equiv\)N bond of AN), and 2926 cm\({}^{-1}\) (stretching -CH\({}_{2}\) copolymer backbone) [72]. In this series (1-Ref vs. 1-RM), no significant differences can be observed between the analyzed samples. However, the band's intensity at 1450 cm\({}^{-1}\) is visibly lower after RM integration. This latter band is attributed to the in-plane deformation of the aliphatic CH\({}_{2}\) groups in the copolymer [75]. The band's intensity reduction can be attributed to physical interactions of the backbone with RM, which reduces the intensity of vibrations. Figure 2B (2-RM and 2-Ref spectra) indicates the appearance of characteristic bands of the copolymer at 3428 cm\({}^{-1}\) (O-H), 1735 (C=O), 2241 cm\({}^{-1}\) (C\(\equiv\)N), and 2929 cm\({}^{-1}\) (-CH\({}_{2}\)), but also the decrease in the band intensity at 1456 cm\({}^{-1}\) in the spectrum of 2-RM. For the last series of samples, 3-RM and 3-Ref, the spectra (Figure 2C) are somewhat different from the previous series, presenting (i) a large hump in the region of 2300-3600 cm\({}^{-1}\), which can be attributed to the higher capacity of the C3 copolymer to retain intramolecular water (C3 contains the highest amount of AA 20%) [72], (ii) lower intensities of characteristic bands from the copolymer  
Figure 2: FTIR spectra of analyzed composite copolymer beads compared to RM alone and their corresponding precursor copolymer: (**A**) C1-based series; (**B**) C2-based series; (**C**) C3-based series. (3447 cm\({}^{-1}\), 1741 cm\({}^{-1}\), 2238 cm\({}^{-1}\), and 2926 cm\({}^{-1}\)) as a result of increased copolymer-RM interactions, and (iii) a significant decrease in the band intensity characteristic for -CH\({}_{2}\) deformation that shifts to 1436 cm\({}^{-1}\) after the addition of RM (3-RM spectrum). The following TGA results (Figure 3) were used to characterize the thermal stability of beads and compute the RM content after complete combustion of the copolymeric phase. For all copolymers and composite beads, three distinct mass loss ranges can be noticed between 25 and 200 \({}^{\circ}\)C, 220 and 500 \({}^{\circ}\)C, and 500 and 750 \({}^{\circ}\)C (Figure 3A-C). The first mass loss is accompanied by endothermic effects (Figure 3D-F) caused by drying and loss of residual solvent molecules. The following two decomposition steps above 200 \({}^{\circ}\)C are accompanied by exothermic events (Figure 3B,D,F), indicating oxidation thermal decomposition reactions.