## 3 Conclusions and Future Recommendations  
Factual data presented in this review proves once again how complex the systems are, nanocomposites of the type of filled polymers and how the effects of nano-fillers on the transport properties of the corresponding membranes are in some cases unpredictable. However, as a result of the formation of nanocomposites of this type, unique membrane characteristics can be achieved. This applies both to porous and to continuous polymer composites containing nano-fillers. Great prospects in this field of membrane science are associated with the appearance of special techniques for the inclusion of nanoparticles in the material [43; 52; 151], with the expansion of the spectrum of nano-fillers from which a useful effect is expected [45; 52; 148; 152; 153], as well as with the appearance of methods for analyzing and visualizing the distribution and the state of fillers in matrices of different morphologies [29; 51; 135; 154]. New polymeric materials are engaged in the synthesis of nanocomposite membranes, including those responsive to stimuli, and are also capable of self-organization or forming  
Figure 30: Pervaporation properties of (**a**) PAI-1 and (**b**) PAI-1-SNF films (Cyh—cyclohexane, EtOH—ethanol, MeOH—methanol, HOH—water). The sequence of penetrants during the pervaporation is as follows: direction 1: Cyh \(\rightarrow\) EtOH \(\rightarrow\)MeOH \(\rightarrow\) HOH; direction 2: HOH \(\rightarrow\) MeOH \(\rightarrow\) EtOH \(\rightarrow\) Cyh [150]. compositionally heterogeneous films [92; 97; 102; 155; 156; 157]. Their use makes it possible to influence the nature of the distribution of nano-fillers in the matrix. Composite membranes obtained acquire a new set of properties, in particular, for the pervaporation separation of liquids, as illustrated above, as well as in a number of review papers [158; 159]. An analysis of the results presented in the review shows that all cases under consideration can be classified into three categories for which properties of composite materials are determined by:  
1. characteristics of nanoparticles introduced into the polymer matrix--their functional, dimensionality, quantity and distribution pattern in a polymer medium;
2. effects of nano-fillers on the polymer, which lead to a change in its supramolecular organization, in particular, to the formation of films whose structural-morphological properties differ significantly from those characteristic of the original polymer itself;
3. characteristics of the region at the boundary of the inorganic and polymer phases. It is in this area of the composite where each of the components manifests itself as a participant in most processes, and that its functional groups may have a different reactive capacity under specific spatial conditions, in particular under conditions of limited movement of molecules or fragments thereof. In this connection, the question arises of the role of interaction between the polymer and inorganic phases, the adhesion and formation of nano- or larger-sized voids. Only an integrated approach and consideration of all three of these situations can lead to the development of an algorithm for the directed change in the properties of membrane materials, taking into account a special separation problem. Methods of studying in the variant \"from the opposite\", as well as the methods of gradual elimination of individual factors of influence can be used for the investigation of such systems, which are not easily accessible for analysis by direct analytical methods. Such methods include the technique of alternative choice that we have illustrated in our works with an alternative choice of a polymer matrix or nanoparticles, other things being equal.