Depth heterogeneity of elemental composition, concentration of functional groups and degree of crosslinking in the active layers of reverse osmosis and nanofiltration membranes

Orlando Coronell, Mari Gonzalez, Benito Jose Marinas, David G Cahill

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We have studied the depth heterogeneity of the elemental composition, concentration of ionized functional groups and degree of polymer crosslinking in the active layer of the ESNA nanofiltration (NF) and FT30 reverse osmosis (RO) membranes. We studied the elemental composition of the bulk of the active layers using Rutherford backscattering spectrometry (RBS), and of the surface of the active layers using X-ray photoelectron spectroscopy (XPS). We also studied the concentration of functional groups by preparing membrane samples using the ion-probing procedure reported in our previous studies, and analyzing the prepared samples using RBS, XPS and time-of-flight secondary ion-mass spectrometry (TOF-SIMS). Our results show that the concentration of carboxylic groups and degree of polymer crosslinking in the active layer of the ESNA and FT30 membranes are higher near the top surface than in the bulk of the active layer. In contrast, amine groups were found to be preferentially located in the bottom ~ 100 nm of the FT30 active layer.

Original languageEnglish (US)
Title of host publication2009 AWWA Membrane Technology Conference and Exposition
StatePublished - 2009
Event2009 AWWA Membrane Technology Conference and Exposition - Memphis, TN, United States
Duration: Mar 15 2009Mar 18 2009

Other

Other2009 AWWA Membrane Technology Conference and Exposition
Country/TerritoryUnited States
CityMemphis, TN
Period3/15/093/18/09

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

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