Free Volume in C60 Modified PPO Polymer Membranes by Positron Annihilation Lifetime Spectroscopy

Jan Kruse, Klaus Rätzke, Franz Faupel, D.M. Sterescu, Dimitrios Stamatialis, Matthias Wessling

Research output: Contribution to journalArticleAcademicpeer-review

25 Citations (Scopus)

Abstract

PPO (poly(2,6-dimethyl-1,4-phenylene oxide)) is a well-known membrane material showing good gas separation properties. The incorporation of nanoparticles can enhance or deteriorate the performance of composite membranes, sometimes depending only on the way of the composite preparation. We have modified the PPO polymer with C60 fullerenes up to a content of 2 wt %. Previous investigations showed a strong dependence of permeability on whether the C60 is simply dispersed in the polymer or chemically bonded to the polymer chains. Free volume effects were suggested as an explanation but not experimentally confirmed. Here, we present free volume studies by positron annihilation lifetime spectroscopy. An additional long positron lifetime shows the increased free volume of composite samples, while the high electron affinity of C60 helps to indicate the homogeneity of the samples. Combining the presented results with permeability measurements refines the understanding of this promising membrane material.
Original languageUndefined
Pages (from-to)13914-13918
JournalJournal of physical chemistry B
Volume111
Issue number50
DOIs
Publication statusPublished - 2007

Keywords

  • IR-71615
  • METIS-243831

Cite this