Currently, membrane technologies are widely applied in various industries. They are alternative processes to traditional separation methods (for example, distillation, extraction, adsorption, etc.) because of low energy consumption, compact equipment, simplicity and flexibility in operation, and environmental friendliness. The focus will be done on two membrane processes applied for the separation of liquid mixtures such as ultrafiltration and pervaporation due to their (1) high relevance for practical application and (2) specific difference, both in the driving force and in the membrane structure (non-porous for pervaporation, porous for ultrafiltration). Ultrafiltration is one of the most demanded membrane methods in various industries: dairy, food, textile, pharmaceutical and metallurgy, and in particular, for water treatment. This method is used to separate high molecular weight from low molecular weight components. The most promising and developing process for the separation of liquid mixtures of low molecular weight substances is pervaporation. This method is actively used for the concentration, fractionation and purification. It allows separating of isomers, azeotropic mixtures, close-boiling and thermally unstable substances, which is difficult to separate by traditional separation methods. Especially, this method found wide applications for the dehydration of organic mixtures.
Modern problems of chemical technology determine the relevance and necessity of not only the development of these membrane processes, but also the search for novel membranes with tailored properties. The efficient and promising ways to achieve the tailored properties of polymer materials are the complex application of bulk and surface modifications/functionalization of membranes from well-known polymers. It should also be noted that the most important type of modified materials are polymer nanocomposites, which include nanoparticles as modifiers. The introduction of these modifiers allows flexible and targeted changes in the physicochemical characteristics of the membrane material and purposefully to improve the transport characteristics of membranes (non-porous and porous).

To demonstrate the effect of nanoparticles on the ultrafiltration membrane characteristics, the modification of ultrafiltration membranes based on well-known polyphenylene oxide and polyphenylene isophthalamide, modified by carbon nanoparticles such as carbon nanotubes, graphite and fullerene, will be considered.

The effect of varying conditions of a modification on the pervaporation membrane characteristics of widely used polymer polyvinyl alcohol (PVA) will be considered. Bulk and surface modifications will be applied to overcome the trade-off between the permeability and selectivity of the polymeric membranes.