In this study, the gas-liquid membrane contactor was considered for regeneration of the roomtemperature ionic liquids (RTIL) that can be used as physical solvents for carbon dioxide capture process at elevated pressures. Poly[1-(trimethylsilyl)-1-propyne] (PTMSP) was selected as a membrane material due to its high mass transport characteristics and good mechanical properties. Nine different RTILs, such asand [P66614][Phos], were used to evaluate the solvent-membrane compatibility. The long-term sorption tests (40+ days) revealed that the solvent-membrane interaction is mainly determined by the liquid surface tension regardless of viscosity and molecular size of RTILs. For instance, [Emim][BF4] and [Emim][DCA], having the surface tension of 60.3 and 54.0 mN/m, demonstrated a very low affinity to the bulk material of PTMSP (sorption as low as 0.02 g/g; no swelling); while for the next ionic liquid [Bmim][BF4] with surface tension of 44.4 mN/m, the sorption and swelling of PTMSP was 0.79 g/g and 21%, respectively. The long-term RTIL permeation test (p=40 bar, T=50°С, t>400 hours) confirmed that there is no hydrodynamic flow through PTMSP for [Emim][DCA] and [Emim][BF4]. The concept of CO2 stripping from RTIL with the membrane contactor by the pressure (p=40 bar) and temperature (T=20°С) swing was proofed by using PTMSP membrane and [Emim][BF4]. The overall mass transfer coefficient value was equal to(1.6-3.8)•10 -3 cm/s with respect to liquid flow rate. By using the resistance-in-series model, it was shown that the membrane resistance contribution to the gas transfer was estimated to be approximately 8%.

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The "green" synthesis of galactomannan sulfates using a sulfamic acid-urea mixture has been studied for the first time. The effect of the time and temperature of the galactomannan sulfation process on the degree of substitution of galactomannan sulfates has been investigated. It is shown that, at a temperature of 70°C with an increase in the process time up to 120 min, the degree of substitution increases up to 0.70. An increase in the process temperature up to 80°C leads to the production of galactomannan sulfates with a degree of substitution of 1.67. With a further increase in the process temperature to 90°C, the galactomannan structure is partially destructed, and the degree of substitution decreases. Embedding of the sulfate groups into the galactomannan structure has been confirmed by elemental analysis and Fourier-transform infrared spectroscopy. In addition, the initial and sulfated galactomannans have been characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and gel permeation chromatography. The thermal analysis shows that the initial galactomannan exhibits endothermic peaks at 254 and 294°C and an exothermic peak at 315°C, while sulfated galactomannan exhibits endothermic peaks at 209 and 275°C and an exothermic peak at 281°C. Using atomic force microscopy, it has been shown that the sulfated galactomannan film consists of spherical particles with an average diameter of 200-300 nm; according to the phase contrast data, it has the uniform composition without extraneous impurities.

For the development of high efficiency porous supports for composite membrane preparation, polysulfone (PSf) hollow fiber membranes (outer diameter 1.57 mm, inner diameter 1.12 mm) were modified by air plasma using the low temperature plasma treatment pilot plant which is easily scalable to industrial level and the Piranha etch (H 2 O 2 + H 2 SO 4 ). Chemical and plasma modification affected only surface layers and did not cause PSf chemical structure change. The modifications led to surface roughness decrease, which is of great importance for further thin film composite (TFC) membranes fabrication by dense selective layer coating, and also reduced water and ethylene glycol contact angle values for modified hollow fibers surface. Furthermore, the membranes surface energy increased two-fold. The Piranha mixture chemical modification did not change the membranes average pore size and gas permeance values, while air plasma treatment increased pore size 1.5-fold and also 2 order enhanced membranes surface porosity. Since membranes surface porosity increased due to air plasma treatment the modified membranes were used as efficient supports for preparation of high permeance TFC membranes by using poly[1-(trimethylsilyl)-1-propyne] as an example for selective layer fabrication.