The separation of equimolar mixtures of i-butane and n-butane through poly(1-trimethylsilyl-1-propyne)/MFI composite membranes was studied. Membranes were characterized by XRD and SEM. Addition of 50 wt% MFI particles into a PTMSP matrix showed increased permeability and simultaneous improved selectivity in the temperature range 25-200 °C. The best improvement was seen at 150 °C for the composites, giving almost threefold increase in permeability and 56% higher n-butane/i-butane selectivity over the pure polymer. To our knowledge, this is the first successful demonstration of the incorporation of a molecular sieve into a polymer matrix for butane isomer separations. The composite membranes were also tested for separations of n-hexane/2,2-dimethylbutane and p-xylene/o-xylene.
Bibliographical noteFunding Information:
We gratefully acknowledge the financial support of NSF NIRT, CBET-0403574, and CBET-0522518. All characterizations were performed at the Minnesota Characterization Facility, which receives support from NSF through the National Nanotechnology Infrastructure Network (NNIN). We thank S. Maheshwari (University of Minnesota) for the microtomy work.
Copyright 2008 Elsevier B.V., All rights reserved.
- Hybrid materials
- Permeation properties