scholarly journals Substituted Polynorbornene Membranes: A Modular Template for Targeted Gas Separations

2021 ◽  
Author(s):  
Xinyi Wang ◽  
Trevor Wilson ◽  
Dmitry Alentiev ◽  
Maria Gringolts ◽  
Eugene Finkelshtein ◽  
...  

Polynorbornenes are ideal materials for systematic structure-property investigations designed to correlate gas-transport properties to polymer structure. The modular nature of norbornene-based systems provides a facile route towards the synthesis of...

2017 ◽  
Vol 30 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Guangliang Song ◽  
Lina Wang ◽  
Dandan Liu ◽  
Jianan Yao ◽  
Yiming Cao

Polyimides (PIs) with single phenyl pendant substitution were prepared based on three diamines containing phenyl pendant group, namely, 2,5-bis(4-aminophenoxy) biphenyl, 2-phenyl-4,4′-diaminodiphenyl ether, and 2,5-diaminobiphenyl (p-PDA), with the dianhydride component of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride, respectively. The physical properties of the membranes were examined, including thermal properties, fractional free volume ( FFV), solubility, and morphological structures, and were compared with the analogues without phenyl pendant. Gas transport properties of the membranes were investigated and discussed from the viewpoint of structure–property relationship. For 6FDA-derived PI membranes, gas permeability increased as the degree of PI backbone rigidity leveled up. Gas transport properties were not improved by the incorporation of phenyl pendant group for 6FDA type containing ether linkage and marginally improved as compared between PI (6FDA/p-PDA) and PI (6FDA/p-phenylenediamine (PDA)). To increase the phenyl substitution density of 6FDA/PDA-type backbone, a novel diamine bearing two phenyl pendant groups, that is, 2,6-diphenyl-1,4-diaminobenzene (p, p′-PDA) was synthesized, and PI derived from 6FDA and p, p′-PDA was prepared. The gas permeability coefficients of PI (6FDA/p, p′-PDA) were remarkably larger than those of PI (6FDA/p-PDA) and PI (6FDA/PDA).


2015 ◽  
Vol 493 ◽  
pp. 766-781 ◽  
Author(s):  
Zachary P. Smith ◽  
Guiomar Hernández ◽  
Kristofer L. Gleason ◽  
Advaith Anand ◽  
Cara M. Doherty ◽  
...  

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1282
Author(s):  
Gleb O. Karpov ◽  
Ilya L. Borisov ◽  
Alexey V. Volkov ◽  
Eugene Sh. Finkelshtein ◽  
Maxim V. Bermeshev

Polynorbornenes represent a fruitful class of polymers for structure–property study. Recently, vinyl-addition polynorbornenes bearing side groups of different natures were observed to exhibit excellent gas permeation ability, along with attractive C4H10/CH4 and CO2/N2 separation selectivities. However, to date, the gas transport properties of fluorinated addition polynorbornenes have not been reported. Herein, we synthesized addition polynorbornene with fluoroorganic substituents and executed a study on the gas transport properties of the polymer for the first time. A norbornene-type monomer with a C6F5 group, 3-pentafluorophenyl-exo-tricyclononene-7, was successfully involved in addition polymerization, resulting in soluble, high-molecular-weight products obtained in good or high yields. By varying the monomer concentration and monomer/catalyst ratio, it was possible to reach Mw values of (2.93–4.35) × 105. The molecular structure was confirmed by NMR and FTIR analysis. The contact angle with distilled water revealed the hydrophobic nature of the synthesized polymer as expected due to the presence of fluoroorganic side groups. A study of the permeability of various gases (He, H2, O2, N2, CO2, and CH4) through the prepared polymer disclosed a synergetic effect, which was achieved by the presence of both bulky perfluorinated side groups and rigid saturated main chains. Addition poly(3-pentafluorophenyl-exo-tricyclononene-7) was more permeable than its metathesis analogue by a factor of 7–21, or the similar polymer with flexible main chains, poly(pentafluorostyrene), in relation to the gases tested. Therefore, this investigation opens the door to fluorinated addition polynorbornenes as new potential polymeric materials for membrane gas separation.


2020 ◽  
Vol 2 (6) ◽  
pp. 399-406
Author(s):  
E. A. Grushevenko ◽  
I. L. Borisov ◽  
D. S. Bakhtin ◽  
V. V. Volkov ◽  
A. V. Volkov

2019 ◽  
Vol 217 ◽  
pp. 183-194 ◽  
Author(s):  
N. Belov ◽  
R. Chatterjee ◽  
R. Nikiforov ◽  
V. Ryzhikh ◽  
S. Bisoi ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2199
Author(s):  
Khadija Asif ◽  
Serene Sow Mun Lock ◽  
Syed Ali Ammar Taqvi ◽  
Norwahyu Jusoh ◽  
Chung Loong Yiin ◽  
...  

Polysulfone-based mixed matrix membranes (MMMs) incorporated with silica nanoparticles are a new generation material under ongoing research and development for gas separation. However, the attributes of a better-performing MMM cannot be precisely studied under experimental conditions. Thus, it requires an atomistic scale study to elucidate the separation performance of silica/polysulfone MMMs. As most of the research work and empirical models for gas transport properties have been limited to pure gas, a computational framework for molecular simulation is required to study the mixed gas transport properties in silica/polysulfone MMMs to reflect real membrane separation. In this work, Monte Carlo (MC) and molecular dynamics (MD) simulations were employed to study the solubility and diffusivity of CO2/CH4 with varying gas concentrations (i.e., 30% CO2/CH4, 50% CO2/CH4, and 70% CO2/CH4) and silica content (i.e., 15–30 wt.%). The accuracy of the simulated structures was validated with published literature, followed by the study of the gas transport properties at 308.15 K and 1 atm. Simulation results concluded an increase in the free volume with an increasing weight percentage of silica. It was also found that pure gas consistently exhibited higher gas transport properties when compared to mixed gas conditions. The results also showed a competitive gas transport performance for mixed gases, which is more apparent when CO2 increases. In this context, an increment in the permeation was observed for mixed gas with increasing gas concentrations (i.e., 70% CO2/CH4 > 50% CO2/CH4 > 30% CO2/CH4). The diffusivity, solubility, and permeability of the mixed gases were consistently increasing until 25 wt.%, followed by a decrease for 30 wt.% of silica. An empirical model based on a parallel resistance approach was developed by incorporating mathematical formulations for solubility and permeability. The model results were compared with simulation results to quantify the effect of mixed gas transport, which showed an 18% and 15% percentage error for the permeability and solubility, respectively, in comparison to the simulation data. This study provides a basis for future understanding of MMMs using molecular simulations and modeling techniques for mixed gas conditions that demonstrate real membrane separation.


1992 ◽  
Vol 25 (2) ◽  
pp. 788-796 ◽  
Author(s):  
D. H. Weinkauf ◽  
H. D. Kim ◽  
D. R. Paul

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