Study of Gas Transport Phenomenon in Layered Polymer Nanocomposite Membranes

Patel, Anish; Acharya, N.K.

doi:10.1002/9781119364795.ch10

Cited by 5 publications

(9 citation statements)

References 26 publications

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“…The kinetic diameter and permeability values are taken from the obtained result of TR polyimides (350, 400, and 450 C) and pure HAB-6FDA polymer. [17] From the result of Figure 6, we can say that when we increased the amount of silica nanoparticles and heating temperature for thermal rearrangement, there is a gain in permeability for all different gases. Here, polymer chain mobility is restricted because rigid layer development around the nanoparticles is not distributed uniformly.…”

Section: Resultsmentioning

confidence: 88%

“…From this table, it was observed that as we increase the temperature from 300 to 400 C, the intensity of the beam passing through the membrane film decreased; this is due to the different compositions of organic and inorganic phases on the surface of the membrane film due to the composition of silica nanoparticles and thermal rearrangement process. [17] Moreover, some changes in the morphological structure of the membrane surface are observed because of the composition of silica nanoparticles with polymer solution modified by the intermolecular chain packing of the membrane surface. Therefore, the composite TR 400 C absorbed more light intensity than TR 300 C and TR 350 C because of the change in the morphological structure.…”

Section: Resultsmentioning

confidence: 99%

“…In this system, a gas permeation cell is connected with a vacuum pump towards the upstream side of the permeation cell; a gas supply unit includes a controller with a pressure transducer is used to measure pressure variations. [17] For accurate estimations, the overall system disclosed a steady vacuum to any uncertain value inside the F I G U R E 3 Schematic diagram of the constant volume/variable pressure system F I G U R E 2 HAB-6FDA polyimide with a ortho-functional chemical structure after the thermal rearrangement (TR) process system. Hence, the upstream volume and downstream volume of gas were empty to degas the membrane film.…”

Section: Methodsmentioning

confidence: 99%

“…[15,16] Similarly, the recent work has indicated that the purified climate assumes a significant part in the TR modification process for an ortho-functional polyimide. [17,18] Another adjustment in the layer morphology cloud is made by scattering inorganic fillers into the organic frame and the additional free volume available to move molecules of gases, which improves gas separation. In the polymer nanocomposite (PNC) membranes, the transformation of gas molecules depends on molecule size, molecule agglomeration, and a proper blend of inorganic/ polymer filler.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and characteristics of HAB‐6FDA thermally rearranged polyimide nanocomposite membranes

Patel

Acharya

2021

Polymer Engineering & Sci

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The thermal rearrangement of polyimides of ortho‐positioned functional group membranes improves the gas permselectivity properties of the polyimide precursor. For this experiment, HAB‐6FDA polyimide was synthesized from 3,3 dihydroxy‐4,4‐diamino‐biphenyl (HAB) and 2,2‐bis‐(3,4‐dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) by chemical imidization. A sample was modified from a pure polymer to silica nanoparticle composition. Furthermore, a modification was carried out by thermal rearrangement reaction at temperatures of 350, 400, and 450°C. The thermal property of these membrane films was characterized by differential scanning calorimetry (DSC), FTIR, opacity experiment, and free volume analysis. Permeability decreases with an increase in the kinetic diameter of gasses, which is normal behavior for glassy polymers. The composition of silica nanoparticles slightly changes the permeability in the polyimide. The combined effect of silica nanoparticles and thermal rearrangement of the HAB‐6FDA membrane has shown an excellent performance. The thermal rearrangement with nanocomposite shows a significant impact on a larger effect on permeation for lighter gases, that is, H2, CO2, and O2, compared with N2 and CH4. Particularly for H2/CH4 gas pair, it lies over Robeson's 2008 upper bound limit, which fits the composition in the novel class for the gas separation membranes.

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Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis and characteristics of HAB‐6FDA thermally rearranged polyimide nanocomposite membranes

Patel

Acharya

2021

Polymer Engineering & Sci

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“…The thermal treatment for models used in gas permeability and concentration experiments are developed to replicate the thermal rearrangement to samples, TR tests are heated from ambient conditions to 300°C at a rate of 5°C/min, then kept at 300°C for 1 hour. By this rearrangement technique it's ensures that complete iridization of the sample [26]. The temperature is then risen at a level of 50 °C/min to the required TR heat.…”

Section: Thermal Rearrangementmentioning

confidence: 99%

Spectroscopic and Transport Behavior of HAB-6FDA Thermally Rearranged (TR) Nanocomposite Membranes

Patel

Acharya

2021

Preprint

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Nanocomposite membranes are a class of innovative filtering materials made up of nanofillers embedded in a polymeric or inorganic oxide matrix that functionalized for the membrane. Thermally rearranged (TR) polymers are found to have a good blending of selectivity and permeability. Chemical iridization is a process for used to make HAB-6FDA polyimide from 3,3 dihydroxy-4,4 diamino-biphenyl (HAB) & 2,2-bis-(3,4-dicarboxyphenyl) hexafluoro propane dianhydride (6FDA). The sample is first changed from a pure polymer membrane to a silica nanofiller doped polymer layer and explain thermally rearrangement for gas permeability in polymer nanocomposite layers and its relationship with kinetic diameter of different gases. The selectivity is decreases as the permeability increases that shows on a trade-off relationship between permeability & selectivity. The CO2 permeability of the HAB-6FDA TR polymers is greater than that of other classes of polymers by equal free volume and indicating that these TR polymers have free volume distribution that supports high permeability. Thermally rearranged polymer nanocomposite exhibits higher gas permeability than that of silica doped and pure polymer. The selectivity for H2/N2 and H2/CO2 gas pairs exceeds towards Robeson's upper bound limit and in case of H2/CH4 gas pair this limit were crossed the Robeson’s upper bond limit. UV spectroscopy shows the change in transmission at higher wavelengths, while XRD show the reduction in FWHM with thermal treatment temperature. Polymer nanocomposite can be utilized to obtain high purity hydrogen gas for refinery and petrochemical applications.

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Impact of dope extrusion rate and multilayer polydimethylsiloxane coating on asymmetric polyethersulfone hollow fiber membrane for CO₂/N₂ and CO₂/CH₄ separation

Zainuddin

Ahmad

2022

Asia-Pacific J Chem Eng

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Carbon dioxide (CO 2 ) emissions to the atmosphere have greatly contributed to climate change as the concentration has increased since the pre-industrial period. Various mitigation strategies have been developed to combat climate change with membrane being one of the growing alternatives. Pristine hollow fiber (HF) membrane typically exhibits lower selectivity as compared to dense flat sheet membrane. In this study, we developed an asymmetric HF polyethersulfone (PES) membrane with critical concentration at two different dope extrusion rate (DER) at 3 and 6 mL/min to be studied for CO 2 /N 2 and CO 2 / CH 4 gas separation for flue gas and biogas upgrading applications by testing the fabricated membrane with pure gas permeation test with variable pressure at room temperature. It was observed that HF membrane extruded with high DER exhibits finger-like structure beneath the skin layer with more pinholes compared to HF extruded with low DER. The gas permeance was observed to increase in linear fashion as function of upstream pressure while the gas selectivity appears to be relatively constant regardless of upstream pressure. Meanwhile, polydimethylsiloxane (PDMS) coated HF PES membrane shows lower gas permeance as compared to its pristine membrane with improved CO 2 /N 2 and CO 2 /CH 4 selectivity. HF PES membrane extruded at 3 mL/min shows relatively low gas permeance, CO 2 /N 2 and CO 2 /CH 4 selectivity as compared to HF PES extruded at 6 mL/min. Additionally, this study shows that sequential coating of PDMS layer does not improve gas selectivity performance of the fabricated asymmetric PES HF membrane while the gas permeance reduction was observed.

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Study of Gas Transport Phenomenon in Layered Polymer Nanocomposite Membranes

Cited by 5 publications

References 26 publications

Synthesis and characteristics of HAB‐6FDA thermally rearranged polyimide nanocomposite membranes

Synthesis and characteristics of HAB‐6FDA thermally rearranged polyimide nanocomposite membranes

Spectroscopic and Transport Behavior of HAB-6FDA Thermally Rearranged (TR) Nanocomposite Membranes

Impact of dope extrusion rate and multilayer polydimethylsiloxane coating on asymmetric polyethersulfone hollow fiber membrane for CO₂/N₂ and CO₂/CH₄ separation

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Study of Gas Transport Phenomenon in Layered Polymer Nanocomposite Membranes

Cited by 5 publications

References 26 publications

Synthesis and characteristics of HAB‐6FDA thermally rearranged polyimide nanocomposite membranes

Synthesis and characteristics of HAB‐6FDA thermally rearranged polyimide nanocomposite membranes

Spectroscopic and Transport Behavior of HAB-6FDA Thermally Rearranged (TR) Nanocomposite Membranes

Impact of dope extrusion rate and multilayer polydimethylsiloxane coating on asymmetric polyethersulfone hollow fiber membrane for CO2/N2 and CO2/CH4 separation

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Impact of dope extrusion rate and multilayer polydimethylsiloxane coating on asymmetric polyethersulfone hollow fiber membrane for CO₂/N₂ and CO₂/CH₄ separation