## 3 Results and Discussion
### Characterization of Magnetic PMO Nanoparticle Systems  
The magnetic ethylene- and phenylene-bridged PMO NPs were prepared under similar reaction conditions by utilizing different organosilane monomers. Figure 1a shows a representative scanning electron microscopy (SEM) image in which spherical and monodispersed nanoparticles can be clearly seen. Figure 1b-d, showing TEM images, confirms the presence of magnetic nanoparticles in the cores inside highly ordered mesostructures. It presents scanning transmission electron microscopy (STEM) and transmission electron microscopy (TEM) images of the resulting magnetic ethylene-bridged PMO NPs. Figure 2 shows magnetic phenylene-bridged PMO NPs. Under the same synthetic conditions, the resulting M-Phenylene PMO NPs exhibited different structural and textural properties. The obtained smoothed-surface spherical system exhibited some polydispersity where mesostructure ordering was not clearly observed. However, the magnetite nanoparticles were also settled in the cores of these nanoparticles. Figure 1: (**a**) SEM, (**b**) STEM, and (**c–d**) TEM micrographs of M-Ethylene PMO NPs. The average diameter and the outer surface charge of the magnetic PMO nanoparticles were determined by dynamic light scattering analysis (DLS). The obtained average size of M-Ethylene PMO NPs ranged between 85 and 150 nm and their zeta potential value was \(-28.6\) mV (Figure 3). With M-Phenylene PMO NPs, this system exhibited an average diameter of 221.2 nm with a \(-9.06\) mV zeta potential value (Figure 4). The obtained magnetic PMO NP systems were further examined using EDX spectroscopy and EDX mapping analysis in order to confirm all the elemental compositions in both systems. From the EDX spectroscopy results shown in Figures 5 and 6, the existence of magnetite nanoparticles inside the  
Figure 4: Size distribution (**a**) and zeta potential (**b**) analysis of Magnetic Phenylene-PMO NPs. Figure 3: Size distribution (**a**) and zeta potential analysis (**b**) of Magnetic Ethylene-PMO NPs. Figure 2: (**a**) SEM and (**b**) TEM micrographs of M-Phenylene PMO nanoparticles (NPs). cores was confirmed. As supportive results, the EDX mapping analysis clearly shows the deposition of all other elements including silica and oxygen that compose the particles' silica network, whereas the magnetic nanoparticles were mostly localized in the cores. In addition to the TEM results shown previously, the XRD pattern of M-Ethylene PMO NPs (Figure 7a) indicated a well-resolved peak in the range of 20 = 1.5\({}^{\circ}\)-2.5\({}^{\circ}\), whereas the Phenylene-PNO NPs exhibited a broad XRD peak (Figure 7b), which confirmed the previous TEM results of distorted mesostructures in these nanoparticles. In addition, both XRD patterns exhibited the characteristic peaks of magnetite nanoparticles at 20 = 30\({}^{\circ}\), 35\({}^{\circ}\), 43\({}^{\circ}\), 53\({}^{\circ}\), 57\({}^{\circ}\), and 63\({}^{\circ}\). The compositional information of M-Ethylene PMO NPs and M-Phenylene PMO NPs was characterized by FT-IR spectroscopy (Figure 8). The FTIR spectra of both systems were very similar, displaying distinct absorbance peaks at 796, 1028, 1093, and 1271 cm\({}^{-1}\), which can be assigned to Si-C vibrations. In addition, the absorption bands at 1154 cm\({}^{-1}\) and at the interval of 2950-3730 cm\({}^{-1}\) in both curves are assigned to the asymmetrical stretching of siloxane groups (Si-O-Si) and Si-OH stretching vibrations, respectively. The absorbance peaks at 2850-2927 cm\({}^{-1}\) are assigned to C-H stretching from both nanoparticle systems. In addition, the presence of the oleate group coating on the magnetite nanoparticles is indicated by the bands at the interval 2853-2930 and 1634 cm\({}^{-1}\), which are attributed to the stretching of C-H and the C=C groups, respectively. Figure 5: EDX spectroscopy (Left) and EDX mapping analysis (Right) of M-Ethylene PMO NPs. Figure 6: EDX spectroscopy (Left) and EDX mapping analysis (Right) of M-Phenylene PMO NPs.