title: Insights into Free Volume Variations across Ion-Exchange Membranes upon Mixed Solvents Uptake by Small and Ultrasmall Angle Neutron Scattering.
abstract: Ion-exchange membranes are composite separation materials increasingly used in a variety of electro-membranes and electrochemical processes. Although promising for solvent reclamation, to date, their main applications are limited to aqueous environments due to physicochemical and microstructural changes of the materials upon exposure to nonaqueous and mixed solvents solutions, affecting long-term stability and separation performance. In the present work, the structural changes of commercial and novel hybrid ion-exchange membranes in mixed methanol/water and ethanol/water solutions are assessed for the first time using ultra- and small-angle neutron scattering techniques. The interface between the ion-exchange functional layer and the mechanical support of the membranes is evaluated in the ultralow-q region, while a broad solvent-dependent peak at the mid-q region was correlated to the microstructural properties which are related to the free volume across the ion-exchange domains and to the materials electrical and nanoscale mechanical properties. The results of this study may offer new opportunities toward the development of an efficient separation process using ion-exchange membranes for the purification of fermentation broths toward biofuel generation.
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, VIC 3216, Australia.
authors.forename: Francois-Marie
authors.initials: FM
authors.lastname: Allioux
authors.affiliation: Bragg Institute, Australian Nuclear Science and Technology Organisation , Lucas Heights, NSW 2234, Australia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Garvey
authors.affiliation: Bragg Institute, Australian Nuclear Science and Technology Organisation , Lucas Heights, NSW 2234, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Rehm
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, VIC 3010, Australia.
authors.forename: Blaise L
authors.initials: BL
authors.lastname: Tardy
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, VIC 3010, Australia.
authors.forename: Raymond Riley
authors.initials: RR
authors.lastname: Dagastine
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, VIC 3216, Australia.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Hodgson
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, VIC 3216, Australia.
authors.forename: Lingxue
authors.initials: L
authors.lastname: Kong
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, VIC 3216, Australia.
authors.forename: Ludovic Francis
authors.identifier: http://orcid.org/0000-0002-0264-4024
authors.initials: LF
authors.lastname: Dumée
keywords: electrodialysis; ion-exchange membranes; ionic clusters swelling; liquid AFM nanoindentation; small-angle neutron scattering