Alkene/alkane permselectivities of a carbon molecular sieve membrane

Suda, Hiroyuki; Haraya, Kenji

doi:10.1039/a606385c

Cited by 88 publications

(39 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They showed that the permeability of CMSM increased for the oxidized membranes whereas lower permeability was observed for sintered membranes. Besides, Suda and Haraya [23] explored the change of pore dimension of carbon membranes formed by calcinating under mild activation to exhibit excellent selectivity for alkene/alkane separation. On the other hand, Hayashi et al [24] have successfully controlled the pore sizes and increased the selectivity of carbon membranes by chemical vapor deposition of propylene.…”

Section: Introductionmentioning

confidence: 99%

“…Many studies have reported that a CMSM with tailored microstructure (pore size, pore volume, etc.) could be obtained by controlling the pyrolysis conditions [2,6,9,13,15,[17][18][19] and post-/pre-treatment conditions [7,10,[20][21][22][23][24]. On the other hand, CMSMs can be modified to improve their permeation properties or to solve several problems inherent to their structures.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides

Tin

Chung

Kawi

et al. 2004

Microporous and Mesoporous Materials

View full text Add to dashboard Cite

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides Tin, P.; Chung, T-S.; Kawi, S.; Guiver, Michael AbstractTwo brand-new modification technologies were developed for pyrolyzing the carbon molecular sieve membranes (CMSMs) with excellent separation efficiency. The modifications were performed on polymeric precursors. It is believed that the space filling effect by these modifications could considerably alter the separation performance of resultant carbon membranes. Firstly, a cross-linking modification was performed on polymeric precursors at room temperature before pyrolysis. The effectiveness of chemical crosslinking technology in improving gas separation capability of CMSMs was investigated. In this study, the permeation properties of carbon membranes derived from cross-linked Matrimid were characterized as a function of cross-linking density. Results demonstrated that the permeability of modified CMSMs decreased with increasing in cross-linking density. Detailed examination reveals that cross-linking modification increased the selectivity at a low degree of cross-linking but reduced the selectivity at a higher degree of cross-linking. The improvement of separation efficiency at low degree of cross-linking is presumably related to the swelling of polymer chains by methanol during cross-linking modification. Consequently, the second extremely simple modification method by using pure methanol immersion was developed. It was found that the CMSMs derived from methanol-treated precursors exhibited superior transport properties. Methanol treatment yielded CMSMs with higher selectivities if compared to CMSMs based on untreated and cross-linked Matrimid. Therefore, it can be concluded that the swelling of polymer chains by methanol appears to be an effectual modification method to produce the CMSMs with excellent separation properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides

Tin

Chung

Kawi

et al. 2004

Microporous and Mesoporous Materials

View full text Add to dashboard Cite

show abstract

“…Moreover, as compared to polymeric materials, carbonized membranes have higher tolerance to harsh environments due to the sluggish chemical reactivity and better thermal resistance. The microstructure of carbon membranes from polyimides is determined by a number of factors including: (1) the different chemical structure of polyimides which induces dissimilar chain packing, thermal stability, molecular flatness and in-plane orientation [27,28]; (2) the pyrolysis conditions such as temperature, atmosphere and heating rate [29,30]; (3) the pre-treatment of polyimide before carbonization using thermostabilization, polymer blending, nonsolvent immersion or chemically grafted side groups [31][32][33][34][35][36][37]; (4) post-treatment of carbonized membranes by oxidation or chemical vapor deposition [38][39][40].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, cross-linking and carbonization of co-polyimides containing internal acetylene units for gas separation

Xiao

Chung

Guan

et al. 2007

Journal of Membrane Science

View full text Add to dashboard Cite

Cross-linkable polyimides containing internal acetylene units have been synthesized by random copolymerization of 6FDA dianhydride, 2,3,5,6-tetramethyl-1,4-phenylenediamine (Durene) and 4,4 ′ -diaminodiphenylacetylene (p-intA) diamine as materials for gas separation. Compared with 6FDA-Durene polyimide, 6FDA-Durene/p-intA co-polyimide shows denser polymer chain packing, which is confirmed by wide-angle X-ray diffraction (WAXD). The thermally treated co-polyimides are insoluble in various solvents and show an increase in T g , indicating the formation of network structures among the polymer chains. Differential scanning calorimetry (DSC) and FT-Raman suggest that cross-linking arises from Diels-Alder cycloaddition between the internally arranged acetylene units along the polymer main chain, resulting in extended conjugated aromatic structures. The thermally cross-linked membranes show enhanced resistance to CO 2 plasticization up to around 5 × 10 6 Pa (700 psi). The rigidified membrane structure provides increased gas selectivity without severely compromising gas permeability. The gas separation performance of carbonized membranes is remarkably superior to those of neat and cross-linked copolyimides because of a large increase in rigidification in the polymer matrix. A Diels-Alder cycloaddition reaction produces a much more rigid and planar conjugated aromatic structure in the polymer chains and results in a higher degree of graphitization during carbonization, which is confirmed by XPS and WAXD. Carbon membranes derived from co-polyimides with more internal acetylene units show much better gas separation performance than those derived from polyimides without internal acetylene units.

show abstract

“…Investigations of the functional group found that trimethylsilyl groups improved the permeability, whereas sulfonyl groups enhanced the ideal selectivity. PPO derivative-based carbon membranes showed good separation performance, comparable to that of polyimide carbon membranes 10) , indicating that PPO is a promising precursor candidate for hollow-fiber carbon membranes. Metal-containing carbon membranes derived from SPPO were also studied.…”

Section: Development Of Novel Hollow-fiber Carbon Membranesmentioning

confidence: 81%

Development and Application of Novel Hollow-fiber Carbon Membranes Derived from Poly(phenylene oxide)

Yoshimune

2015

J. Jpn. Petrol. Inst.

View full text Add to dashboard Cite

Novel hollow-fiber carbon membranes were successfully fabricated using poly(phenylene oxide) (PPO) and derivatives as a precursor polymer. These free-standing carbon membranes had permeation properties above the upper bound of conventional polymeric membranes including PPO precursor polymers. Metal-containing carbon membranes derived from sulfonated PPO (SPPO) were also prepared by the ion exchange method and the effect of metal cations on the gas transport properties was studied. Transition metal ions such as Ag significantly enhanced gas permeabilities without affecting the ideal selectivities. The development of flexible hollowfiber carbon membranes was successfully achieved using SPPO as a precursor polymer. Superior flexibility combined with excellent gas separation performance were obtained by pyrolysis at 600 ºC. The present findings indicate the potential for commercial application of carbon membranes. Some applications of carbon membranes were also investigated such as selective dehydration of olefin gases, alcohol dehydration by pervaporation and CO2/CH4 mixed gas separation.

show abstract

Alkene/alkane permselectivities of a carbon molecular sieve membrane

Cited by 88 publications

References 12 publications

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides

Synthesis, cross-linking and carbonization of co-polyimides containing internal acetylene units for gas separation

Development and Application of Novel Hollow-fiber Carbon Membranes Derived from Poly(phenylene oxide)

Contact Info

Product

Resources

About