In this work, performance of composite membranes was investigated for desalination of Kashan city’s water via pervaporation process. PEBA/PAN/PE, PEBA/PSF/PE and PEBA+NaX/PSF/PE composite membranes that used, was synthesized via a phase inversion route. For all experiments under 45◦, salt rejection was too high and equals to 99.9% that this quantity dropped by increasing the temperature that cause membrane swelling in high temperatures. Water contact angle and water take-up were measured to evaluate the hydrophilicity of the membrane. Also the effect of operating conditions including feed temperature and permeate pressure on permeability and selectivity is discussed. A permeate flux of 4.93 kg/m2h with salt rejection of 99.9% could be achieved at a feed temperature of 50oC and a vacuum of 0.04 bar. Apparent diffusion coefficients of water at various permeate pressure and feed temperature are calculated. The most effective parameter was feed temperature.

In this work, polyamid-polyether block copolymer (PEBA) was synthesized as a selective top layer of nanostructure ceramic supports and their performance on separation of polar (CO2) and non-polar (N2) gases were evaluated. The effects of several parameters such as polymer solution concentration and number of coated layers on the performance of prepared composite membranes were investigated. PEBA/ceramic nanocomposite membranes were fabricated by dip-coating of ceramic nanocomposite porous support in 3, 10 and 30 wt. % of copolymer solutions with different dip-coating steps. Chemical and morphological studies on the synthesized copolymer and hybrid membranes were carried out by FT-IR spectroscopy, Atomic force microscopy (AFM), scanning electron microscopy (SEM) and optical microscopy (OM). The results showed that hybrid membranes with 30 wt. % of copolymer solution with 4 dip-coating steps had better performance in the separation of CO2 and N2 processes.

This study involved the synthesis of iron-doped macroporous TiO2 sheets, which were subsequently incorporated into a polyether block amide (PEBA) matrix. The investigation focused on various properties ofthe resulting membranes, including morphology, chemical structure, thermal behavior, crystallinity, mechanical strength, and separation characteristics. The findings indicated that the incorporation of FeTiO2 sheets enhanced the mechanical strength of the membranes by forming physical bonds with the polymer chains. Additionally, these sheets created facilitated transport mechanism through Lewis acid centers, resulting in an increase in CO2 permeability. However, the formation of hydrogen bonds led to a stiffening of the polymer matrix, which limited the enhancement of CO2 permeability to 12.4% in the optimal membrane compared to the pure membrane. Conversely, the increased stiffness of the polymer matrix reduced N2 permeability while enhancing CO2/N2 selectivity by 136% in the optimal membrane relative to the pure membrane, thereby allowing it to surpass the upper Robson line

In this research, Polyether block amide (PEBA) containing different loadings of α-Al2O3 particles was deposited on top of the polysulfone (PSf ) supports to form PEBA 1657‒α-Al2O3/PSf multilayer composite mixed matrix membranes (MCMMMs). Multilayer Composite structure was used to overcome the sedimentation of fillers in the polymer matrix. Moreover, alpha phase of the Al2O3 particles was applied to improve the distribution of these particles at higher loadings. SEM, XRD, and FTIR tests were applied to study morphology, crystalline structure, and chemical structure of the membranes, respectively. Gas permeation properties of the membranes were also measured using three different pure gases (CO2, CH4, and N2) at the pressure of 7 bar and temperature of 25 ºC. CO2 permeance and ideal selectivity of CO2/CH4, and CO2/N2 for the optimum MCMMM with 20 wt% loading of α-Al2O3 particles were 25% (117.5 Barrer), 81.5 % (32), and 86.5% (57) higher than that of multilayer composite neat membrane (MCNM), respectively. The molecular simulation results confirmed the results of the experimental studies and approved that the α-Al2O3 particles are right candidates for improving the PEBA performance for CO2 separation.

In this research, pure polyether block amide (PEBA) membrane and PEBA membrane containing tween surfactant were made using molecular simulation and analyzed from a molecular point of view. In order to investigate the structure of the membranes, their density and free fraction volume were calculated. Also, the radial distribution function was plotted in order to investigate the interaction of CO2 gas with PEBA polymer chains and tween molecules, and the permeability and solubility coefficients against CO2 and N2 gases were obtained. Moreover, the selectivity of CO2 over N2 was calculated for the membranes. The results showed an increase in the solubility and diffusion coefficients of CO2, followed by an increase in the permeability of this gas by adding tween to the polymer matrix, while the selectivity of the membrane containing tween decreased due to the increase in the diffusion coefficient of N2 in this membrane compared to the pure membrane.

In this work, the structure of a poly ether block amide (PEBA) polymeric membrane was investigated using molecular simulation study. This membrane performance for the separation of CO2 from N2 was evaluated. In this regard, the density and fractional free volume (FFV) for this membrane were calculated and compared with experimental data. The results showed the conformity of the molecular simulation results with experimental work results. In addition, the mobility of PEBA chains and its polyether and polyamide parts were measured on a molecular scale which cannot be measured on a laboratory scale. Then the diffusion and solubility coefficients of gases were determined for this membrane and the permeability of CO2 and CO2/N2 selectivity were calculated. The performance properties of the simulated membrane showed that, solubility has a greater role in CO2/N2 selectivity than diffusivity in this membrane, so that CO2 permeability and CO2/N2 selectivity were 116.9 and 130 Barrer, respectively.