title: Membranes with artificial free-volume for biofuel production.
abstract: Free-volume of polymers governs transport of penetrants through polymeric films. Control over free-volume is thus important for the development of better membranes for a wide variety of applications such as gas separations, pharmaceutical purifications and energy storage. To date, methodologies used to create materials with different amounts of free-volume are based primarily on chemical synthesis of new polymers. Here we report a simple methodology for generating free-volume based on the self-assembly of polyethylene-b-polydimethylsiloxane-b-polyethylene triblock copolymers. We have used this method to fabricate a series of membranes with identical compositions but with different amounts of free-volume. We use the term artificial free-volume to refer to the additional free-volume created by self-assembly. The effect of artificial free-volume on selective transport through the membranes was tested using butanol/water and ethanol/water mixtures due to their importance in biofuel production. We found that the introduction of artificial free-volume improves both alcohol permeability and selectivity.
authors.affiliation: Department of Chemical &Biomolecular Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: Nikos
authors.initials: N
authors.lastname: Petzetakis
authors.affiliation: CSIRO Manufacturing Private Bag 10, Clayton South, Victoria 3169, Australia.
authors.forename: Cara M
authors.initials: CM
authors.lastname: Doherty
authors.affiliation: CSIRO Manufacturing Private Bag 10, Clayton South, Victoria 3169, Australia.
authors.forename: Aaron W
authors.initials: AW
authors.lastname: Thornton
authors.affiliation: Materials Sciences Division &Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: X Chelsea
authors.initials: XC
authors.lastname: Chen
authors.affiliation: Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Pepa
authors.initials: P
authors.lastname: Cotanda
authors.affiliation: CSIRO Manufacturing Private Bag 10, Clayton South, Victoria 3169, Australia.
authors.forename: Anita J
authors.initials: AJ
authors.lastname: Hill
authors.affiliation: 1] Department of Chemical &Biomolecular Engineering, University of California, Berkeley, California 94720, USA [2] Materials Sciences Division &Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA [3] Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Nitash P
authors.initials: NP
authors.lastname: Balsara