## 2 Results and Discussion
### Materials Characteristics
#### 2.1.3 SAXS Investigation
Figure 3: _Cont._  
The highest level of scattering was observed for DVB:TEVS = 1:2 sample, whereas the lowest was noticed for DVB:TEVS = 2:1. Due to the presence of scattering objects (polymer domains) in the materials' body, their size and relative quantity may be responsible for the scattering capacity and observed differences. Although all tested materials have a similar type of morphology, polymer domains in the DVB:TEVS = 1:2 sample should be marked as more visible. The phenomenon can be associated with the enhanced porosity of material as a result of greater amount of TEVS. In the case of this sample (DVB:TEVS = 1:2), increased porosity is associated with a higher amount of crosslinking agent and may cause the presence of additional nanometer forms (pores) able to generate the scattering effect [50; 51]. In this way, a comparison of the level of scattering by hybrid samples can provide information about the degree of surface homogeneity [52; 53]. The scattering properties of organic-inorganic materials can be discussed by Porod law. In this case, the scattering effect at large q values is applied. According to [PERSON] law, the scattering curves of particle systems and porous materials with smooth surfaces decay proportionally to q\({}^{-3}\) at large angles (I(q) \(\approx\) k\({}_{3}\)/ q\({}^{3}\) for smeared data). When [PERSON]'s law is observed for experimental data (like in Figure 3b), it is a good indication of well-defined interfaces between regions of different electron density. Here, the scattered intensity is proportional to the reciprocal of suitable power of scattering vector (I(q)-k\({}^{4}\) for non-smeared SAXS data and I(q)-k\({}^{3}\) for smeared SAXS data). Figure 3b shows the calculated Porod plots for investigated samples. Porod curves display a plateau and the SAXS data asymptotically approaches a constant value. The procedure allows evaluating the Porod  
Figure 3: Experimental SAXS profiles corresponding to hybrid microspheres with various amounts of organic and inorganic components (**a**) Porod plots, and Porod constants determined from experimental patterns (**b**). The black arrows show the range of scattering vector suitable for the Porod linear range. The log-log plots of SAXS intensity in the power-law range (**c**). constant k based on the asymptotic decay of the scattering curve at the higher angles. The amplitude of the asymptote is proportional to the particle's surface-area-to-volume ratio and concentration. The most important feature of the Porod law suggests that the Porod constant is proportional to the surface area and the square of the electron density contrast. In this case, a simple comparison of the Porod constant allows illustrating the differences in the specific surface of materials in a way that is much simpler and faster than conventional methods of testing porosity. Comparing the absolute S/V values calculated from the Porod approximation, a clear decrease in the value for the sample containing the majority of the organic phase is visible. The S/V values equal 0.061 A\({}^{-1}\), 0.048 A\({}^{-1}\) and 0.039 A\({}^{-1}\) for DVB:TEVS = 1:2, DVB:TEVS = 1:1, and DVB:TEVS = 2:1 samples, respectively. This suggests creating an extended three-dimensional surface of material containing mostly an inorganic blowing agent and a significant reduction of this surface by increasing the degree of smoothness using larger amounts of the organic phase. The estimated values of the interface surface from SAXS data (S\({}_{\text{SAXS}}\)) are given in Table 1 and are equal to 521, 402 and 311 m\({}^{2}\)/g, respectively. Comparison of the specific surface area determined by using two different methods (low-temperature nitrogen sorption method: Brunauer-Emmett-Teller (BET) and SAXS indicates a correlation between both techniques for evaluating structural characteristics generated by polymer-domains and pores. Slight differences indicate a low amount of closed porosity of the microspheres. Small-angle X-ray scattering allows conducting statistical analysis of scatters nanostructures.