Please use this identifier to cite or link to this item:
|Title:||Characterizing free volumes and layer structures in polymeric membranes using slow positron annihilation spectroscopy|
|Citation:||Jean, Y.C., Chen, H., Zhang, S., Chen, H., Lee, L.J., Awad, S., Huang, J., Lau, C.H., Wang, H., Li, F., Chung, T.-S. (2011). Characterizing free volumes and layer structures in polymeric membranes using slow positron annihilation spectroscopy. Journal of Physics: Conference Series 262 (1) : -. ScholarBank@NUS Repository. https://doi.org/10.1088/1742-6596/262/1/012027|
|Abstract:||Positron annihilation spectroscopy coupled with a newly built slow positron beam at National University of Singapore has been used to study the free volume, pore, and depth profile (0 - 10 μm) in cellulose acetate polymeric membrane at the bottom and top sides of membranes for ionic separation in water purification applications. The S and R parameters from Doppler broadening energy of annihilation radiation representing free volumes (0.1-1 nm size) and pores (>1 nm-μm) as a function of depth have been analyzed into multilayers, i.e. skin dense, transition, and porous layers, respectively. The top side of membrane has large free volumes and pores and the bottom side has a skin dense layer, which plays a key role in membrane performance. Positron annihilation lifetime results provide additional information about free-volume size and distribution at the atomic and molecular scale in polymeric membrane systems. Doppler broadening energy and lifetime spectroscopies coupled with a variable mono-energy slow positron beam are sensitive and novel techniques for characterization of polymeric membrane in separation applications. © 2011 IOP Publishing Ltd.|
|Source Title:||Journal of Physics: Conference Series|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Feb 19, 2019
WEB OF SCIENCETM
checked on Feb 11, 2019
checked on Feb 9, 2019
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.