Tags

Type your tag names separated by a space and hit enter

Positron annihilation spectroscopic evidence to demonstrate the flux-enhancement mechanism in morphology-controlled thin-film-composite (TFC) membrane.
Environ Sci Technol 2005; 39(6):1764-70ES

Abstract

In this study, positron annihilation lifetime spectroscopy (PALS) is applied to explain the flux-enhancement mechanism in thin-film-composite (TFC) membranes prepared by using dimethyl sulfoxide (DMSO) as an additive in the interfacial polymerization. The TFC membranes show a large increase in water flux, up to 5-fold, compared to nonadditive membrane. Atomic force microscopy (AFM) shows that surface roughness and surface area increase when DMSO in the aqueous phase solution phase works to increase miscibility of the aqueous and the organic phase by reducing the solubility difference of two immiscible solutions. X-ray photoelectron spectroscopy (XPS) reveals the variation of the chemical compositions to the extent that there is a considerable increase in the cross-linked amide linkages of the flux-enhanced TFC membranes. The effects of these structural changes on the molecular-size free volume properties are evaluated by PALS studies. The PALS results are the first to experimentally show that the thin films of cross-linked aromatic polyamide RO membranes are composed of two types of pores having radii of about 2.1-2.4 A from tau3, network pore, and 3.5-4.5 A from tau4, aggregate pore. The increase in the size and number of network pores by means of DMSO addition during interfacial polymerization enhances the water flux notably. The size of aggregate pores also increases and may contribute to enhance water flux, although their number inevitably decreases as the number of network pores becomes increased. Details on the correlations between RO performances and o-Ps lifetime parameters are clearly described based on the pore-flow model of reverse osmosis developed by Sourirajan et al.

Authors+Show Affiliations

Research Institute of Advanced Materials, Seoul National University, San 56-1, Shillim-dong, Gwanak-gu, Seoul 151-742, Korea.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15819236

Citation

Kim, Sung Ho, et al. "Positron Annihilation Spectroscopic Evidence to Demonstrate the Flux-enhancement Mechanism in Morphology-controlled Thin-film-composite (TFC) Membrane." Environmental Science & Technology, vol. 39, no. 6, 2005, pp. 1764-70.
Kim SH, Kwak SY, Suzuki T. Positron annihilation spectroscopic evidence to demonstrate the flux-enhancement mechanism in morphology-controlled thin-film-composite (TFC) membrane. Environ Sci Technol. 2005;39(6):1764-70.
Kim, S. H., Kwak, S. Y., & Suzuki, T. (2005). Positron annihilation spectroscopic evidence to demonstrate the flux-enhancement mechanism in morphology-controlled thin-film-composite (TFC) membrane. Environmental Science & Technology, 39(6), pp. 1764-70.
Kim SH, Kwak SY, Suzuki T. Positron Annihilation Spectroscopic Evidence to Demonstrate the Flux-enhancement Mechanism in Morphology-controlled Thin-film-composite (TFC) Membrane. Environ Sci Technol. 2005 Mar 15;39(6):1764-70. PubMed PMID: 15819236.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Positron annihilation spectroscopic evidence to demonstrate the flux-enhancement mechanism in morphology-controlled thin-film-composite (TFC) membrane. AU - Kim,Sung Ho, AU - Kwak,Seung-Yeop, AU - Suzuki,Takenori, PY - 2005/4/12/pubmed PY - 2005/7/26/medline PY - 2005/4/12/entrez SP - 1764 EP - 70 JF - Environmental science & technology JO - Environ. Sci. Technol. VL - 39 IS - 6 N2 - In this study, positron annihilation lifetime spectroscopy (PALS) is applied to explain the flux-enhancement mechanism in thin-film-composite (TFC) membranes prepared by using dimethyl sulfoxide (DMSO) as an additive in the interfacial polymerization. The TFC membranes show a large increase in water flux, up to 5-fold, compared to nonadditive membrane. Atomic force microscopy (AFM) shows that surface roughness and surface area increase when DMSO in the aqueous phase solution phase works to increase miscibility of the aqueous and the organic phase by reducing the solubility difference of two immiscible solutions. X-ray photoelectron spectroscopy (XPS) reveals the variation of the chemical compositions to the extent that there is a considerable increase in the cross-linked amide linkages of the flux-enhanced TFC membranes. The effects of these structural changes on the molecular-size free volume properties are evaluated by PALS studies. The PALS results are the first to experimentally show that the thin films of cross-linked aromatic polyamide RO membranes are composed of two types of pores having radii of about 2.1-2.4 A from tau3, network pore, and 3.5-4.5 A from tau4, aggregate pore. The increase in the size and number of network pores by means of DMSO addition during interfacial polymerization enhances the water flux notably. The size of aggregate pores also increases and may contribute to enhance water flux, although their number inevitably decreases as the number of network pores becomes increased. Details on the correlations between RO performances and o-Ps lifetime parameters are clearly described based on the pore-flow model of reverse osmosis developed by Sourirajan et al. SN - 0013-936X UR - https://www.unboundmedicine.com/medline/citation/15819236/Positron_annihilation_spectroscopic_evidence_to_demonstrate_the_flux_enhancement_mechanism_in_morphology_controlled_thin_film_composite__TFC__membrane_ L2 - https://dx.doi.org/10.1021/es049453k DB - PRIME DP - Unbound Medicine ER -