The permeability and selectivity of nanocomposite membrane of PEBAx 1657/PEI/SiO2 for separation of CO2, N2, O2, CH4 gases: A data set

The poly ether-block-amide (PEBAx)/Poly-ether-imide (PEI)/SiO2 nanocomposite membranes were fabricated using the solution casting method and utilized for separation of N2, O2, CH4, and CO2 gases. The effect of SiO2 nanoparticles loading on permeability and selectivity of gases using the nanocomposite membranes was tested. The data showed that the permeability of the gases increased with increasing SiO2 nanoparticle content. dBy adding SiO2 nanoparticles (10 wt%), the permeability of N2, O2, CH4, and CO2 gases elevated from 0.39, 1, 1.83 and 11.1 to 2.01, 1.95, 2.98 and 19.83 Barrer unit, respectively (at a pressure of 2 Bar). In contrast, with increasing SiO2 content the selectivity of the studied gases decreased. The morphology, crystallinity and the functional groups of the fabricated membranes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) techniques. The data presented confirm the influence of the nanoparticles on the membrane structure and thus on the permeability and selectivity of the membranes.


a b s t r a c t
The poly ether-block-amide (PEBAx)/Poly-ether-imide (PEI)/SiO 2 nanocomposite membranes were fabricated using the solution casting method and utilized for separation of N 2 , O 2 , CH 4, and CO 2 gases. The effect of SiO 2 nanoparticles loading on permeability and selectivity of gases using the nanocomposite membranes was tested. The data showed that the permeability of the gases increased with increasing SiO 2 nanoparticle content. dBy adding SiO 2 nanoparticles (10 wt%), the permeability of N 2 , O 2 , CH 4, and CO 2 gases elevated from 0.39, 1, 1.83 and 11.1 to 2.01, 1.95, 2.98 and 19.83 Barrer unit, respectively (at a pressure of 2 Bar). In contrast, with increasing SiO 2 content the selectivity of the studied gases decreased. The morphology, crystallinity and the functional groups of the fabricated membranes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fouriertransform infrared spectroscopy (FTIR) techniques. The data presented confirm the influence of the nanoparticles on the membrane structure and thus on the permeability and selectivity of the membranes.

Data
The X-Ray Diffraction (XRD) of SiO 2 nanoparticles and fabricated membranes is shown in Fig. 1. Also, the FTIR analysis of SiO 2 nanoparticles and membranes are depicted in Fig. 2. Four SEM images of prepared membranes have been indicated in Fig. 3. The effect of SiO 2 nanoparticle loading on permeability in various feed gas pressure is shown in Fig. 4. Table 1 is related to the kinetic diameter and condensability of the studied gases. The selectivity of CH 4 , N 2 , and O 2 gases is depicted in Table 2. The raw data for this work are presented in the Supplementary section.

Value of the Data
This data can be useful for developing the nanocomposite polymeric membranes. The study may be applicable for oil, gas and petrochemical industries for natural gas sweetening and purification processes. Our data can be helpful for power plants to the separation of CO 2 gas released from fossil fuels. This paper introduces a membrane to the world of industry that can be useful for controlling carbon dioxide gas and thus controlling global warming.
were dispersed in di-methyl-formamide by the ultrasonic process for 60 min at 50 C. A 6% w/v of polymer solution was fabricated by adding Pebax 1657 and PEI (4:1 wt ratio) to the solution at 120 C.
To form a homogeneous solution, the mixing was continued for 24 h. Afterward, the solution was poured on Teflon mold at 70 C. Then, the solvent completely removed from the membranes by vacuum drying in the ambient temperature for 4 h. Finally, the thickness of the prepared membranes was measured by a micrometer. A schematic for the membrane fabrication is illustrated in Fig. 5.

Gas permeability and selectivity measurement
The gas permeability was measured using the time lag method [2,3]. The gas flow rate was obtained using a constant pressure method. In this method, by connecting the downstream space to the water column, and by measuring the changes of water column's height over time, the gas flow rate passing through the membrane is obtained. The gas flow rate can achieve from the slope of the linear part of the water column height as a function of time. Then, the permeability coefficient can be calculated using the following equation [4]: where P is the gas permeability coefficient in the polymer (1 Barrer ¼ cm 3 (STP).cm/cm 2 .S.cmHg), Q is the gas flow rate (cm 3 /s), l is the membrane thickness (cm), A is the cross-section area of membrane (cm 2 ), P 1 and P 2 are the gas pressure in upstream and downstream, respectively. The membrane ideal selectivity respect to a given gas can calculate through the following equation [5]: where a is the membrane ideal selectivity, P i and P j are the gas permeability coefficient of gas (i) and (j), respectively.

Acknowledgment
We thank the Jundi Shapur University of Technology, Iran for their assistance and technical support to conduct this study (through Grant No.: JUST-203).