## 3 Results
Figure 8: Defective areas on the cross-section of the PE film with grafted PS (\(\Delta p\) = 74%) in the presence of DVB (2.5 vol. %). Arrows indicate defects in the grafted layers of PS. Figure 10: (**a**) Phase distribution of the grafted PS in the volume of the PE film (obtained in the cross-section of the membrane); (**b**) the phase particle of the cross-linked PS in the PE matrix (\(\Delta p\) = 74%, [DVB] = 0.5 vol. %). Dotted line indicates the particles of the PE lamella bonded to the surface. Figure 9: Coalescence of the phases of grafted PS in the presence of DVB in the PE matrix (\(\Delta p\) = 74%, [DVB] = 0.5 vol. %). The arrow marks the contact zone of the particles. Thus, the graft polymerization of St in the presence of DVB leads to the formation of hybrid membranes with a complex heterogeneous structure. This is also confirmed by a thermochemical analysis (Figure 11). Five peaks were detected in the typical DSC curve, which were highlighted using the multiple peak fit (Gaussian) functions of the OriginPro 2017 program. The peak temperatures and peak surface areas were 58 \({}^{\circ}\)C (10.3 J/g), 89.9 \({}^{\circ}\)C (18.3 J/g), 93.5 \({}^{\circ}\)C (1.1 J/g), 99.7 \({}^{\circ}\)C (15 J/g), and 104.5 \({}^{\circ}\)C (18.8 J/g), respectively. The total surface area of the crystal phase of PE is 63.64 J/g. The degree of crystallinity of the PE crystallites in relation to the melting heat of an ideal PE crystal was estimated to be 4 (1), 6.3 (2), 0.37 (3), 5.1 (4), and 7.4% (5), respectively. We identified transition 6 as the glass-transition temperature of PS, corresponding to 83 \({}^{\circ}\)C.  
Thus, the dispersion medium is registered: the phases of PE (melting point Tm and degree of crystallinity, Figure 11), the phase of grafted PS distributed in the dispersion medium (glass-transition temperature Tg), and the fragments of cross-linked phases of DVB distributed in both media. In some parts of the PE phase, which probably have an increased content of amorphous fragments, the microphase of the cross-linked PS is surrounded by the crystals (lamellae) of PE (Figure 10b). The membranes obtained in the presence of DVB due to the formation of a three-dimensional structure slightly change their linear dimensions when swelling in organic solvents. However, the solvent sorption does not decrease; in fact, it slightly increases (Figure 12). Apparently, this is due to the formation of a cryptoheterogenic porous structure during grafting. The pore-forming agents are methanol and St. In the films obtained at a high concentration of DVB in the solution of graft polymerization when swelling in o-xylene, the pores are opened and filled with this solvent. They reach a size of several millimeters and are visually distinguishable. Figure 13 shows that the swelling increases both with an increase in the degree of grafting of PS and the content of DVB in the solution of graft polymerization. Figure 2:0 DSC curves of grafted PE copolymer with PS (\(\Delta\)\(p\) = 74%) obtained in the presence of 2.5 vol. % DVB. The peak temperatures and peak surface areas were 1—58 \({}^{\circ}\)C (10.3 J/g), 2—89.9 \({}^{\circ}\)C (18.3 J/g), 3—93.5 \({}^{\circ}\)C (1.1 J/g), 4—99.7 \({}^{\circ}\)C (15 J/g), and 5—104.5 \({}^{\circ}\)C (18.8 J/g), respectively. The total surface area of the crystal phase of PE is 63.64 J/g. The 6 is the glass-transition temperature of PS, corresponding to 83 \({}^{\circ}\)C.  
Thus, the addition of DVB to the grafting solution allows directional control over a wide range of the distribution of the grafted PS over the thickness of the PE film and the morphology of the modified film. The self-diffusion coefficients of water measured by the pulsed field gradient technique in the PE film with grafted PS with different DVB contents are shown in Figure 2:1 As shown in our previous papers, water molecules are situated in two parts with different concentrations of sulfonate groups [21; 22]. There are two types of water molecules in the films with low DVB contents (Table 1).