Mixed metal-organic frameworks

Up to now, a variety of non-zeolite/polymer mixed-matrix membranes have been developed comprising either nonporous or porous non-zeolitic materials as the dispersed phase in the continuous polymer phase. For example, non-porous and porous silica nanoparticles, alumina, activated carbon, poly(ethylene glycol) impregnated activated carbon, carbon molecular sieves, Ti02 nanoparticles, layered materials, metal-organic frameworks and mesoporous molecular sieves have been studied as the dispersed non-zeolitic materials in the mixed-matrix membranes in the literature [23-35]. This chapter does not focus on these non-zeoUte/polymer mixed-matrix membranes. Instead we describe recent progress in molecular sieve/ polymer mixed-matrix membranes, as much of the research conducted to date on mixed-matrix membranes has focused on the combination of a dispersed zeolite phase with an easily processed continuous polymer matrix. The molecular sieve/ polymer mixed-matrix membranes covered in this chapter include zeolite/polymer and non-zeolitic molecular sieve/polymer mixed-matrix membranes, such as alu-minophosphate molecular sieve (AlPO)/polymer and silicoaluminophosphate molecular sieve (SAPO)/polymer mixed-matrix membranes. 

Since the strategy was initially based on catalytic purposes, the surfaces considered initially were mostly (i) highly divided oxides (here are included simple oxides, mixed oxides, zeoUtic materials, mesoporous systems, hybrid organic inorganic materials, metal organic frameworks, etc.) and (ii) highly divided metals (supported or unsupported small metal particles). 

Ferey, G., Millange, E, Morcrette, M., Serre, C., Doublet, M.-L., Greneche, J.-M., and Tarascon, J.-M. 2007. Mixed-valence Li/Fe-based metal-organic frameworks with both reversible redox and sorption properties. Angewandte Chemie International Edition 46, 3259-3263. 

Tanh Jeazet HB, Staudt C, Janiak C. Metal-organic frameworks in mixed-matrix membranes for gas separation. Dalton Trans 2012 41 14003-14027. 

Bae YS, Mulfort KL, Frost H et al (2008) Separation of CO2 from CH4 using mixed-Ugand metal-organic frameworks. Langmuir 24 8592-8598... 

Adams R, Carson C, Ward J et al (2010) Metal organic framework mixed matrix membranes for gas separations. Micropor Mesopor Mater 131 13-20... 

Figure 7.19 Influence of metal organic framework loading on the methanol and tetrahydrofuran permeance of a polyamide-based organic solvent nanoflltration mixed matrix membrane. MeOH, methanol THF, tetrahydrofuran.

J. Campbell, G. Szekely, R.P. Davies, D.C. Braddock, A.G. Livingston, Fabrication of hybrid polymer/metal organic framework membranes mixed matrix membranes versus in situ growth, Journal of Materials Chemistry A 2 (2014) 9260-9271. 

B. Zornoza, C. Tellez, J. Coronas, J. Gascon, F. Kapteijn, Metal organic framework based mixed matrix membranes an increasingly important field of research with a large application potential, Microporous Mesoporous Materials 166 (2013) 67-78. 

X.Y. Chen, H. Vinh-Thang, D. Rodrigue, S. Kaliaguine, Amine-functionalized MIL-53 metal-organic framework in polyimide mixed matrix membranes for CO2/CH4 separation, Industrial Engineering Chemistry Research 51 (2012) 6895-6906. 

This description might well be generalized to remove the word organic, since more recent work has revealed a wealth of inorganic hosts, such as zeolites and polyoxometallates," or mixed metal-organic coordination compounds, such as metal-organic frameworks (MOFs)... 

Hawes CS, NolvachaiY, Kulsing C, Knowles GP, Chafifee AL, Marriott PJ, Batten SR, Turner DR. Metal-organic frameworks as stationary phases for mixed-mode separation applications. Chem Commun 2014 50 3735-7. 

Erucar, L, S. ILesidn, Screening Metal-Organic Framework-Based Mixed-Matrix Membranes for CO/CH4 Separations. Industrial Engineering Chemistry Research, 2011, 50(22), 12606-12616. 

Zomoza et al (2013) reported the first examples of metal organic framework based mixed-matrix membranes outperforming state-of-art polymers. They noted the high application potential of... 

Various treatment methods based on conventional, modem and hybrid technologies have been applied for remediation of F , U and As in many parts of the world. These techniques have been critically reviewed in this chapter. Metal organic framework based mixed-matrix membranes have been reported to outperform state-of-art polymers. These composite membranes containing various adsorbents/fillers such as zeolites have high application potential and should be studied further for removal of heavy metals from wastewater. 

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