Yu. P. Kuznetsov

Deep desalination of water by evaporation through polymeric membranes

Transport properties and structural features of a number of already known and new types of polymeric membranes in desalination of aqueous salt solutions by membrane distillation and pervaporation were studied. The possibility of obtaining distilled water in a single stage by pervaporation from dilute or concentrated aqueous salt solutions was examined for the example of membranes fabricated from celluloses of varied origin (wood, cotton, bacterial).

Nanocomposite based on polyamidoimide with hydrosilicate nanoparticles of varied morphology

Polymeric nanocomposites based on aromatic polyamidoimide and nanotubes of magnesium hydrosilicate Mg3Si2O5(OH)4 with a chrysotile structure were obtained and studied for the first time. The morphology and mechanical and transport properties of the composites formed were analyzed, which enabled optimization of their synthesis conditions.

Effect of molecular weight parameters on gas transport properties of poly(2,6-dimethyl-1,4-phenylene oxide)

The gas permeability of O 2 and N 2 for homogeneous and composite membranes prepared from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) samples with different molecular weight parameters was investigated. Temperature dependencies of gas permeability coefficients and permselectivity were determined for homogeneous membranes. It was established that gas permeability coefficients of homogeneous membranes depend on molecular weight of the polymers used. The gas permeability of composite membranes with a PPO selective layer was investigated as a function of PPO intrinsic viscosity [η] and its casting solution concentration (c). It was shown that under the condition [η].c = const it is possible to obtain composite membranes with the same transport properties by using polymers with different molecular weight parameters.

Interrelation between preparation conditions and structure of asymmetric membranes based on poly((diphenyl oxide amido)-N-phenylphthalimide)

Morphology of asymmetric membranes based on poly((diphenyl oxide amido)-N-phenylphthalimide) was studied by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The effect of preparation conditions on the morphology and transport properties of the membranes was investigated. The test membranes were prepared by the phase-inversion method under the conditions of “wet” casting in the polymer-solvent (N-methyl pyrrolidone)-nonsolvent (water, ethanol, 2-propanol, or aqueous alcohol solutions) systems. Feed casting solutions with a concentration of 10–14 wt %, including those containing a weak nonsolvent (ethyl acetate) were used. A comparative analysis of the structural features and water permeability of the test membranes allows the conclusion that some types of membranes can be used in nanofiltration processes.

Pervaporation Membranes for Separating Mixtures of Methanol and Methyl tert-Butyl Ether

Transport characteristics of new types of bi- and multilayer composite polymer pervaporation membranes and asymmetrical membranes in separating mixtures of methanol and methyl tert-butyl ether were studied. The principles of design of the membranes and their mass-exchange characteristics are treated in terms of the Henis-Tripodi resistance model.

Dehydration of Organic Solvents by Evaporation through Membranes Based on Polyelectrolytic Complexes

Evaporation of binary aqueous-organic mixtures through composite membranes with coatings based on polyelectrolytic complexes including different combinations of polyelectrolytic polycations and polyanions was studied. The possibility of efficient dehydration of organic solvents by their pervaporation was demonstrated.

Structure and Gas Separation Properties of Composite Membranes with Poly(2,2,3,3,4,4,5,5-octafluoro-n-amyl Acrylate) Cover Layer

Effect of the formation procedure on the structure and transport characteristics of poly(2,2,3,3,4,4, 5,5-octafluoro-n-amyl acrylate)-polyamidoimide composite membranes in separation of O2/N2 gas mixture (air) over a wide temperature range is studied.

Prediction of separating characteristics of pervaporation membranes by inverse gas chromatography

The potentiality of inverse gas chromatography to predict separating properties of pervaporation membranes is studied for the example of a membrane composed of a mixture of polyvinyl alcohol and polyacrylic acid. Correlation relationships between the retention time of substances and relative rate of their mass transfer across the membrane were derived. A comparative method for assessment of the membrane selectivity was suggested proposed, and its consistency was checked for pervaporation separation of methanol-methyl acetate-water-acetic acid, methanol-toluene, and ethanol-ethyl acetate mixtures, including those with an azeotropic composition.

Structure and Transport Properties of Films of Mixed Cellulose Esters

Cellulose acetomyristates of varied composition were studied. The sample volume abnormally increases in high-temperature stretching and after swelling in benzene. Cellulose acetomyristates can be used as membranes for separating aromatic and aliphatic hydrocarbons.

Microporous polyimide films based on blends of polyamido acid and cellulose derivatives

The effect of a blowing agent, cellulose diacetate, on the structural nonuniformity and physicomechanical properties of polyimide films was studied by thermogravimetric analysis and scanning electron microscopy. Changes in the gas permeability of the films in the course of thermal degradation of the blowing agent were estimated. The feasibility was demonstrated of using these films for fabrication of composite membranes.