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Mixed matrix membranes based on MIL-101 metal organic frameworks in PIM-1

P Bernardo;JC Jansen;G Clarizia;
2014
2014
Istituto per la Tecnologia delle Membrane - ITM
Inglese
ICOM2014, the 10th International Congress on Membrane and Membrane processes
Sì, ma tipo non specificato
20-25 Luglio, 2014
Suzhou, China
The development of Polymers of Intrinsic Microporosity (PIMs) has given a strong boost to gas separation membrane research. Thanks to ladder-type structures, containing spiro-centres1 or other contortion sites, PIMs obtain high internal surface areas and free volume, which result in an ultra-high permeability2. The spiro-bisindane PIM-1 was shown to surpass the 1991 Robeson upper bound for certain gas pairs and determined the more recent upper bound.3 Mixed matrix membranes (MMMs) have the potential to enhance further the transport properties of polymeric membranes when an appropriate combination of fillers and polymer matrix is used. Usually porous fillers in polymers with a low permeability are used and the improved performance derives mostly from the greatly enhanced permeability induced by the dispersed filler. In this paper, a much more challenging approach is presented, namely to use as the polymer matrix PIM-1, which already performs at the top of the current state of the art, in combination with a Metal Organic Framework (MOF) filler. MOFs, three-dimensional porous coordination polymers, combine an open porosity and large inner surface area.4 The crystalline Cr-terephthalate MIL-101 has both large cages (3.4 nm cavity with ca. 1.6 nm windows) and small cages (2.9 nm cavity with 1.2 nm windows). It presents a very high surface area, more than three times higher than that typically reported for PIM-1. Mixed matrix membranes, containing up to 30% of the MIL-101, were prepared by solution casting. Their characterization was carried out by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), thermo¬gravimetric analysis (TGA), N2 adsorption at 77 K and X-ray diffraction (XRD). The idea is that the size, shape, concentration and spatial distribution of the fillers, and their interactions with the PIM-1 polymer matrix affect the polymer chain packing and thus the available free volume. Thus, besides affecting directly the permeability, the MOFs may also reduce in time the effects of physical ageing. The PIM-1/MIL-101 membranes were highly permeable to gases, even more than PIM-1/ZIF-8-containing membranes.5 The increase in permeability with respect to PIM-1 is mainly related to changes in the gas diffusion and hence to the creation of additional surface area and disruption to polymer packing. The ideal selectivity is not affected and in the case of CO2/CH4 and CO2/N2 separations the performance of the MMMs surpasses the relative upper bound. In addition, the incorporation of MIL-101, particularly as 50 nm nanoparticles, effectively reduced the typical permeability decline over time related to physical aging. Acknowledgements Financial support was received from: the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 228631 "DoubleNanoMem", and the Italian Programma Operativo Nazionale Ricerca e Competitività 2007-2013, project PON01_01840 "MicroPERLA". References 1.P. M. Budd, B. S. Ghanem, S. Makhseed, N. B. McKeown, K. J. Msayib and C. E. Tattershall, Chem. Commun., 230 (2004). 2.P. M. Budd, N. B. McKeown, B. S. Ghanem, K. J. Msayib, D. Fritsch, L. Starannikova, N. Belov, O. Sanfirova, Y. Yampolskii and V. Shantarovich, J. Membr. Sci. 325, 851 (2008). 3.L. M. Robeson, J. Membr. Sci. 320, 390 (2008). 4.O. M. Yaghi, H. Li, C. Davis, D. Richardson and T.L. Groy, Acc. Chem. Res. 31, 474 (1998). 5.A.F. Bushell, et al., J. Membr. Sci., 427, 48-62 (2013).
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info:eu-repo/semantics/conferenceObject
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04 Contributo in convegno::04.02 Abstract in Atti di convegno
P. Bernardo; J.C. Jansen; G. Clarizia; P.M. Budd; M.P. Attfield; A.F. Bushell; M.R. Khdhayyer
   Nanocomposite and Nanostructured Polymeric Membranes for Gas and Vapour Separations
   DOUBLENANOMEM
   FP7
   228631
04.02 Abstract in Atti di convegno
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14243/287853
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