## 3 Results
### FTIR Analysis of Modified Mt  
The representative FTIR spectra of the Mt and modified Mt are shown in Figure 2. For the Mt, the broad absorption bands, at 3446.4 and 1639.8 cm\({}^{-1}\), corresponded to the -OH stretching vibration and H-O-H bending vibration of free adsorbed water within the Mt interlayer, respectively. The characteristic absorption peak at 3632.5 cm\({}^{-1}\) was attributed to the stretching vibration of the Al-OH and Si-OH groups, and these hydroxyl groups were responsible for the reaction with the silane coupling agent [30]. The bands at 1036.1 and 793.4 cm\({}^{-1}\) were representative of the stretching vibration peaks of Si-O and Si-O-Al, respectively. In the case of H-Mt, the decrease in the intensity of the peak at 1036.1 and 793.4 cm\({}^{-1}\) was due to changes in the Si environment produced by the acid treatment, suggesting that the textural character of Mt had been changed. Meanwhile, an increase in the intensity of the bands at 3632.5, 3446.4, and 1639.8 cm\({}^{-1}\) was observed, indicating an increase in the amount of hydroxyl groups and adsorbed water, resulting from the interlayer Na\({}^{+}\) was partly exchanged with protons during the acid treatment. The spectrum of Si-Mt not only had the characteristic bands of Mt, but also exhibited two new peaks at 2928.2 and 2854.0 cm\({}^{-1}\), which were assigned to the antisymmetric and symmetric stretching vibrations of the -CH\({}_{2}\) groups, respectively. In addition, the characteristic peak of \(\gamma\)-MPS, observed at 1723.9 cm\({}^{-1}\) for the C=O stretching vibration, provided supplementary proof that \(\gamma\)-MPS molecules were successfully grafted onto the Mt. For the P-Mt, in addition to these peaks of Mt, the antisymmetric and symmetric stretching vibrations of the -CH\({}_{2}\) groups were also observed. Moreover, the relative intensities of the absorption bands at 3446.4 and 1639.8 cm\({}^{-1}\) decreased due to the decrease in the amount of water after the intercalation of TTPC. These results confirmed the successful intercalation of surfactants into the interlayer spacing of Mt, and that the surface had changed from a hydrophilic to a hydrophobic characteristic [31]. For the H-P-Mt, the appearance of strong absorption bands corresponded to the -CH\({}_{2}\) group, providing supporting information for the successful intercalation of TTPC into the  
Figure 2: FTIR spectra obtained from the Mt and functionalized Mt samples. (**a**) FTIR spectra of (A) Mt, (B) H-Mt, (C) P-Mt, (D) Si-Mt, (E) H-P-Mt, and (F) H-Si-Mt; (**b**) FTIR spectra of (A) Mt, (B) H-Mt, (G) P-Si-Mt, (H) Si-P-Mt, (I) H-Si-P-Mt, and (J) H-P-Si-Mt. H-Mt. Moreover, the peak intensity weakening of the stretching and bending vibrations of the O-H bands indicated that the amount of hydrated Na\({}^{+}\) decreased after the ion exchange reaction. The FTIR spectra of the H-Si-Mt not only exhibited the antisymmetric and symmetric stretching bands of the methylene groups, but also had a characteristic band of the C=O stretching vibration. Furthermore, the reduction in the absorption peak intensity of the adsorbed free water and/or hydroxyl groups provided evidence of the successfully intercalated silanes into the interlayer spacing and/or chemically grafted onto the broken edges and surfaces of the H-Mt [32]. A significant increase in the band intensity at 1723.9 cm\({}^{-1}\) was observed in H-Si-Mt, compared with that of the Si-Mt, indicating that acid activation had a prominent effect on the silylation. The FTIR spectra of the P-Si-Mt, Si-P-Mt, H-Si-P-Mt, and H-P-Si-Mt, as shown in Figure 2b, provided evidence of the presence of both surfactant and silane molecules. Compared with the P-Si-Mt, as expected, the peak intensity weakening of the methylene groups in the H-P-Si-Mt spectra attested that the acid activation could decrease the amount of ion-exchanged surfactants. Similar weakening was also observed for the H-Si-P-Mt, in contrast with Si-P-Mt.