Structure and gas permeation of nanoporous carbon membranes based on RF resin/F-127 with variable catalysts
- PDF / 529,434 Bytes
- 10 Pages / 584.957 x 782.986 pts Page_size
- 33 Downloads / 175 Views
Tonghua Wang and Jieshan Qiu Carbon Research Laboratory, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China (Received 4 June 2014; accepted 14 October 2014)
Nanoporous carbon membranes (NCMs) were fabricated by the blends of resorcinol–formaldehyde (RF) resin and Pluronic F-127 through the processes of assembly, membrane-casting, solidification, and pyrolysis. The effect of the catalyst type (i.e., NaOH and Na2 CO 3) on the structure and property of precursors and their derived NCMs was investigated. The as-obtained precursors and NCMs were characterized by thermogravimetry, differential scanning calorimetry, x-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, elemental analysis, nitrogen adsorption, and gas permeation techniques. The results have shown that defect-free NCMs can be easily procured by the NaOH and Na2CO3 catalysts. In contrast, the precursor made from the Na2CO3 catalyst exhibits higher char yield than that from NaOH after pyrolysis. NaOH-based NCMs are beneficial for the separation of H2/N2 and CO2/N2 gas pairs. Na2CO3-based NCMs are more favorable for the separation of O2/N2 with an ideal selectivity of 6.29 and an O2 permeability of 3.27 Barrer.
I. INTRODUCTION
During the last two decades, the development of nanoporous carbon membranes (NCMs) has been rapidly increasing owing to their excellent gas permeation, thermal resistance, and chemical inertness.1 NCMs have a wide range of potential applications, such as gas separation, membrane reactors, ultrafiltration, sensors, fuel cells, and so on.2–5 However, NCMs are still limited in bench-scale due to the restriction of several unresolved issues. The first and most important issue is how to reduce the production cost to compete with traditional membrane materials in the market.6,7 To attain it, one has to develop cheap precursor, or to remarkably improve the separation performance, to compensate for the production cost of NCMs. Up to now, a lot of precursors have been developed to prepare NCMs, including polyimide, phenolic resin (PR) and its derivatives (e.g., resorcinol– formaldehyde (RF)), polyfurfuryl alcohol, polyphenylene oxide, poly(vinylidene chloride-co-vinyl chloride), polypyrrolone, poly(phthalazinone ether sulfone ketone), etc. Among them, PR or RF is one type of inexpensive polymers with suitable features, such as high char yield and thermal stability, to be applied as NCMs. 8,9 Nevertheless, in recent years, PR (or RF) has not a)
Address all correspondence to this author. e-mail: [email protected], [email protected] DOI: 10.1557/jmr.2014.327 J. Mater. Res., Vol. 29, No. 23, Dec 14, 2014
http://journals.cambridge.org
Downloaded: 14 Mar 2015
received much interest from membrane researchers. The reason lies in two aspects: (a) Poor membraneforming ability of PR making it difficult to prepare defect-free carbon membranes; and (b) low permeability of the as-prepared carbon membranes resulting in unappealing for an industrial concern. Therefore, some m
Data Loading...
