Characterization of multilayer nanofiltration membranes using positron annihilation spectroscopy
Journal
Journal of Membrane Science
Journal Volume
343
Journal Issue
1-2
Pages
147-156
Date Issued
2009
Author(s)
Abstract
Positron annihilation spectroscopy (PAS) coupled with a slow positron beam was used to characterize in situ the layer structure and depth profile of the cavity size in thin film composite (TFC) polyamide nanofiltration (NF) membranes prepared by the interfacial polymerization method. Two techniques, using PAS coupled with a slow positron beam of Doppler broadening energy spectra (DBES) and positron annihilation lifetime spectroscopy (PALS) designed to reveal the layer structure and the cavity sizes contained in a multilayer thin film composite NF membrane, were assessed. To the best knowledge of the authors, a characterization of the depth profile of cavities in NF membranes using PAS coupled with a slow positron beam has never been reported. The membranes selected have a composite structure containing three layers: a selective polyamide layer, a transition layer, and a porous support prepared by the phase inversion technique. Furthermore, the cavity size distribution in the selective top layer plays an important role in determining the performance of the NF membranes. ? 2009 Elsevier B.V. All rights reserved.
Subjects
Membrane characterization
Nanofiltration
Pore size distribution
Positron annihilation spectroscopy
Slow positron beam
SDGs
Type
journal article