Hollow fiber membrane mixed-matrix membranes

Hollow Fiber Asymmetric Mixed-Matrix Membranes... 

Zeolite/polymer mixed-matrix membranes can be fabricated into dense film, asymmetric flat sheet, or asymmetric hollow fiber. Similar to commercial polymer membranes, mixed-matrix membranes need to have an asymmetric membrane geometry with a thin selective skin layer on a porous support layer to be commercially viable. The skin layer should be made from a zeohte/polymer mixed-matrix material to provide the membrane high selectivity, but the non-selective porous support layer can be made from the zeohte/polymer mixed-matrix material, a pure polymer membrane material, or an inorganic membrane material. 

The geometries for asymmetric mixed-matrix membranes include flat sheets, hollow fibers and thin-fihn composites. The flat sheet asymmetric mixed-matrix membranes are formed into spirally wound modules and the hollow fiber asymmetric mixed-matrix membranes are formed into hollow fiber modules. The thin-film composite mixed-matrix membranes can be fabricated into either spirally wound or hollow fiber modules. The thin-film composite geometry of mixed-matrix membranes enables selection of different membrane materials for the support layer and low-cost production of asymmetric mixed-matrix membranes utilizing a relatively high-cost zeolite/polymer separating layer on the support layer. 

Widjojo, N., Chung, T.S., and Kulprathipanja, S. (2008) The fabrication of hollow fiber membranes with doublelayer mixed-matrix materials for gas separation. J. Memhr. Sci., 325 (1), 326-335. 

Dual-layer polyethersulfone (PES)/BTDA-TD1/MD1 co-polyimide (P84) hollow fiber membranes with a submicron PES-zeolite beta mixed matrix dense-selective layer for... 

Keywords Polymeric membrane, phase inversion, hollow fiber, electrospimiing, modification of membranes, graft polymerization, mixed matrix membrane, UV irradiation, tensile strength... 

Polymer matrix selection determines minimum membrane performance while molecular sieve addition can only improve membrane selectivity in the absence of defects. Intrinsically, the matrix polymer selected must provide industrially acceptable performance. For example, a mixed matrix membrane using silicone rubber could exhibit properties similar to intrinsic silicone rubber properties, O2 permeability of 933 Baiters and O2/N2 permselectivity of 2.1 (8). The resulting mixed matrix membrane properties would lie substantially below the upper boimd trade-off curve for gas permeability and selectivity. In contrast, a polymer exhibiting economically acceptable permeability and selectivity is a likely candidate for a successful polymer matrix. A glassy polymer such as Matrimid polyimide (PI) is an example of such a material because it exhibits acceptable properties and current technology exists for formation of asymmetric hollow fibers for gas separation (10). 

A next-future application of MOFs is predicted for MOF-oiganic polymer-based mixed matrix membranes in hollow fiber or spiral wound geometry. Established membrane production technologies such as hollow fiber spinning or foil casting can be used for the preparation of mixed matrix membranes. Further, MOFs match much better with organic polymers than zeolites, for example, even if the latter have been hydrophobized, such as by silylation. 

Mixed matrix hollow fiber membranes made with modified HSSZ-13 zeolite in polyetherimide polymer matrix for gas separation. /. Membr. Sd., 288, 195-207. 

Ismail, A.F., Kusworo, T.D., and Mustafa, A. (2008) Enhanced gas permeation performance of polye-thersulfone mixed matrix hollow fiber membranes using novel Dynasylan Ameo silane agent. /. Memhr. Sci.,... 

Ekiner, O.M. and Kulkarni, S.S. (2003) Process for making mixed matrix hollow fiber membranes for gas separation. US Patent 5,553,805. 

Crosslinked and crosslinkable hollow fiber mixed matrix membrane and method of making the same. US Patent 6,755,900. 

Husain, S. (2006). Mixed Matrix Dual Layer Hollow Fiber Membranes for Natural Gas Separation, in Chemical Biomolecular Engineering, PhD Dissertation, Georgia Institute of Technology. 

O. M. Ekiner, S.S. Kulkarni, Process for making hollow fiber mixed-matrix membrane, US Patent 6663805 (2003). 

For example, Ronco [48] suggested the possibility of mixing the biomaterial of a specific membrane with a sorbent material based on a significant enhancement of internal and backfiltration in hollow-fiber hemodialyzers. Thus, the single membrane will have both characteristics, i.e., diffusion and adsorption for removal of uremic acid, and is called mixed matrix membrane (MMM) [49,50]. The MMM concept had been proposed earlier as an alternative to traditional chromatographic column [51]. 

M.S.L. Tijink, M. Wester, G. Glorieux, K. Gerritsen, J. Sun, P.C. Swart, Z. Borneman, M. Wessling, R. Vanholder, J. A. Joles, D. Stamatiahs, Mixed matrix hollow fiber membranes for removal of protein-bound toxins from human plasma. Biomaterials, 34 (32), 7819-7828,... 

Jiang LY, Chung TS, Cao C, Huang Z, Kulprathipanja S. Fundamental understanding of nano-sized zeolite distribution in the formation of the mixed-matrix single and dual-layer asymmetric hollow fiber membranes. J Membr Sci 2005 252(l-2) 89-100. 

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