## 3 Results
### Structure and Morphology Assessment via XRD Patterns, SEM-EDS, and HRTEM Micrographs  
XRD patterns for natural bentonite (BN), drug-loaded bentonite (BNF), modified bentonite (BA1), and drug-loaded modified bentonite (BA1F) are depicted in Figure 2. The diffractograms show characteristic peaks of montmorillonite along with impurities, such as quartz and feldspar. In BN, the characteristic montmorillonite peaks appear at approximately 5-10\({}^{\circ}\) 20, corresponding to the basal plane d\({}_{001}\) = 14.29 A, confirming the presence of a smectitic structure with calcium intercalation. Additionally, a secondary peak at 4.49 A (d\({}_{020}\)) further supports the identification of montmorillonite as the dominant mineral. The d\({}_{001}\) basal spacing of 39.8 A confirms that the clay is classified as calcium bentonite (Ca-bentonite), as the presence of hydrated calcium cations directly influences the expansion of the crystalline layers [12]. The peak observed around 7\({}^{\circ}\) (20) shows significant variation among the samples, which can be attributed to structural modifications in the montmorillonite layers. This shift and intensity change likely results from interlayer expansion or contraction caused by acid treatment, leading to peak displacement [11; 12]. The presence of quartz is evidenced by an intense peak at approximately 26\({}^{\circ}\) 20, characteristic of the crystalline plane of SiO\({}_{2}\). This peak appears in all samples, indicating that quartz persists even after chemical modifications. Smaller peaks associated with feldspar are observed in the range of 20-30\({}^{\circ}\) 20, corresponding to common impurities in natural bentonite. After acid treatment (BA1), a broadening of the montmorillonite peaks is observed, suggesting a reduction in crystallinity and partial structural disorder due to cation dissolution and impurity removal. This effect is more pronounced in the shift of the d\({}_{001}\) basal peak, indicating a contraction of the layered structure due to the extraction of interlayer ions [12]. SEM images for bentonite adsorbents (BN and BA1) and their respective drug-loaded samples (BNF and BA1F) are presented in Figure 3. As reported in other studies, bentonite \begin{table}
\begin{tabular}{c c c} \hline
**Element** & **BN—Composition (a\%)** & **BA1—Composition (a\%)** \\ \hline Na & 0.87 & 0.00 \\ Mg & 2.06 & 1.93 \\ Others & 4.65 & 2.06 \\ \hline \end{tabular}
\end{table} 
Table 1: _Cont._  
Figure 2: XRD of samples BN, BNF, BA1, and BA1F. exhibits a certain degree of amorphicity due to its undefined morphology at the nanometric scale. The images show variations in particle size, influenced by the treatment and changes in sample composition. In the BN sample, larger and more defined particles are observed, with some spherical agglomerates, indicating a relatively intact clay structure. After acid treatment (BA1), the particles appear more fragmented and disordered, suggesting the removal of interlayer cations and partial dissolution of the clay mineral structure. These morphological changes align with the structural modifications observed in the XRD results, confirming the impact of acid activation and drug incorporation on the physicochemical properties of bentonite [13]. TEM images (Figure 4) highlight significant morphological differences induced by the acid activation process. The BN sample exhibits relatively dense and layered structures with distinguishable plate-like particles, suggesting a well-preserved clay mineral framework. In contrast, the BA1 sample shows a more fragmented and amorphous appearance, with irregular and thinner layers, indicating partial dissolution of the clay structure due to acid leaching. These changes align with the XRD and SEM results, confirming the reduction in crystallinity and increased disorder after acid treatment. The presence of darker regions in the BA1 sample suggests the formation of defects and the removal of interlayer cations, contributing to the modified physicochemical properties of bentonite [14].