Effects of novel silane modification of zeolite surface on polymer chain rigidification and partial pore blockage in polyethersulfone (PES)-zeolite A mixed matrix membranes

Yi Li, Huai Min Guan, Tai-Shung Chung*, Santi Kulprathipanja

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

256 Scopus citations

Abstract

A novel silane coupling agent, (3-aminopropyl)-diethoxymethyl silane (APDEMS) was used in this work to modify zeolite surface for mixed matrix membranes (MMMs). Both elementary analysis and XPS spectra confirm the chemical modification, while BET measurements show no changes in zeolite surface area and total pore volume after the modification. Polyethersulfone (PES)-zeolite 3A, 4A and 5A MMMs were fabricated at high processing temperatures using unmodified and chemical modified zeolite. SEM images of these MMMs indicate the interface between polymer and zeolite phases becomes better if modified zeolite is used. The effects of chemical modification of zeolite surface and zeolite loadings on the gas separation performance of these MMMs were investigated. Both permeability and selectivity of MMMs made from APDEMS modified zeolite are higher than those of MMMs made from unmodified zeolite at 20 wt% zeolite loading because of a decrease in the degree of partial pore blockage of zeolites. The permeability of all studied gases decreases with increasing zeolite content for PES-zeolite 4A-NH2 MMMs, while for PES-zeolite 5A-NH2 MMMs, the gas permeability decreases and then increases with an increase in zeolite loadings. This unique phenomenon implies that using large pore-size zeolite for MMMs would potentially offset the negative effects of partial pore blockage and polymer chain rigidification on permeability. A modified Maxwell model with adjusted parameters was applied to study the PES-zeolite 4A-NH 2 MMM system. The predicted permeability and selectivity show very good agreement with experimental data, indicating the modified Maxwell model is fully capable of predicting the gas separation performance of MMMs made from both unmodified and modified zeolite.

Original languageEnglish (US)
Pages (from-to)17-28
Number of pages12
JournalJournal of Membrane Science
Volume275
Issue number1-2
DOIs
StatePublished - Apr 20 2006

Keywords

  • Maxwell model
  • Mixed matrix membrane
  • Partial pore blockage
  • Polymer chain rigidification
  • Silane modification of zeolite surface

ASJC Scopus subject areas

  • Filtration and Separation
  • Polymers and Plastics

Fingerprint Dive into the research topics of 'Effects of novel silane modification of zeolite surface on polymer chain rigidification and partial pore blockage in polyethersulfone (PES)-zeolite A mixed matrix membranes'. Together they form a unique fingerprint.

Cite this