Most commercial membranes for molecular separations are polymeric and, despite extensive research over the past decades, are based on a mere handful of polymers. However, if membrane technology is to penetrate new and demanding application areas, such as carbon dioxide capture from flue gases, better and more robust membrane materials are needed. For high-volume applications, high permeability is necessary in order to minimize membrane area. It is well known that high permeability is generally associated with poor selectivity, as illustrated by double logarithmic "Robeson" plots of selectivity against permeability [1]. The challenge is to push the bounds of membrane performance to higher permeability, whilst also achieving long-term stability under demanding conditions of use. A step-change in performance is most likely to come through a synergistic combination of materials. Thus, "mixed matrix" or "nanocomposite" membranes have been the focus of much recent research. In the context of the "DoubleNanoMem" project, a wide variety of nanofillers have been utilised with a single polymer, PIM-1 [2], enabling the effects of different kinds of filler to be investigated. A range of porous crystalline materials have been incorporated into PIM-1, including inorganic molecular sieves and metal-organic frameworks, as listed in Table 1. The fillers and nanocomposite membranes have been characterized by scanning electron microscopy (SEM). Figure 1 shows an example of a SEM image for a PIM-1/MIL-101 membrane, and the particle size distribution of MIL-101 determined from the SEM image. Permeation properties have been investigated for nanocomposite membranes both as prepared and after alcohol treatment. Representative selectivity/permeability data for the CO2/N2 pair are shown in Fig. 2. For various fillers, significant enhancements in permeability, compared to pure PIM-1, are achieved for both as prepared and ethanol-treated membranes, with selectivities that are close to, or exceed, Robeson's 2008 upper bound. Acknowledgment The work leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. NMP3-SL-2009-228631, project DoubleNanoMem. AB is supported by the Engineering and Physical Sciences Research Council (EPSRC). References [1]L.M. Robeson, The upper bound revisited, J. Membr. Sci. 320 (2008) 390-400. [2]P.M. Budd et al., Gas permeation parameters and other physicochemical properties of a polymer of intrinsic microporosity: Polybenzodioxane PIM-1, J. Membr. Sci. 325 (2008) 851-860.
Nanocomposite membranes with PIM-1 matrix
JC Jansen;P Bernardo;F Bazzarelli;G Clarizia;F Galiano;A Figoli;
2012
Abstract
Most commercial membranes for molecular separations are polymeric and, despite extensive research over the past decades, are based on a mere handful of polymers. However, if membrane technology is to penetrate new and demanding application areas, such as carbon dioxide capture from flue gases, better and more robust membrane materials are needed. For high-volume applications, high permeability is necessary in order to minimize membrane area. It is well known that high permeability is generally associated with poor selectivity, as illustrated by double logarithmic "Robeson" plots of selectivity against permeability [1]. The challenge is to push the bounds of membrane performance to higher permeability, whilst also achieving long-term stability under demanding conditions of use. A step-change in performance is most likely to come through a synergistic combination of materials. Thus, "mixed matrix" or "nanocomposite" membranes have been the focus of much recent research. In the context of the "DoubleNanoMem" project, a wide variety of nanofillers have been utilised with a single polymer, PIM-1 [2], enabling the effects of different kinds of filler to be investigated. A range of porous crystalline materials have been incorporated into PIM-1, including inorganic molecular sieves and metal-organic frameworks, as listed in Table 1. The fillers and nanocomposite membranes have been characterized by scanning electron microscopy (SEM). Figure 1 shows an example of a SEM image for a PIM-1/MIL-101 membrane, and the particle size distribution of MIL-101 determined from the SEM image. Permeation properties have been investigated for nanocomposite membranes both as prepared and after alcohol treatment. Representative selectivity/permeability data for the CO2/N2 pair are shown in Fig. 2. For various fillers, significant enhancements in permeability, compared to pure PIM-1, are achieved for both as prepared and ethanol-treated membranes, with selectivities that are close to, or exceed, Robeson's 2008 upper bound. Acknowledgment The work leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. NMP3-SL-2009-228631, project DoubleNanoMem. AB is supported by the Engineering and Physical Sciences Research Council (EPSRC). References [1]L.M. Robeson, The upper bound revisited, J. Membr. Sci. 320 (2008) 390-400. [2]P.M. Budd et al., Gas permeation parameters and other physicochemical properties of a polymer of intrinsic microporosity: Polybenzodioxane PIM-1, J. Membr. Sci. 325 (2008) 851-860.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
