Property Control of (Perfluorinated Ionomer)/(Inorganic Oxide) Composites by Tailoring the Nanoscale Morphology.
Abstract
The morphology and properties of perfluorosulfonate ionomers (PFSI's) can be significantly altered by simple changes in the type of counterion used to neutralize the membrane. Furthermore, with a range of counterions, different solution and melt-processing procedures may be used to control the size and shapes of the ionic domains in PFSIs. A major objective of this research was to test our hypothesis that nanophase-separated morphologies of PFSIs act as catalytic - templates that control the morphology of in situ-grown, sol-gel derived phases. This hypothesis was verified for PFSI/SiO2 and PFSI/organically-modified SiO2 hybrids using SAXS. Nanostructures based on the alkoxides of Si, Ti, Al, Zr and alkylalkoxysilanes were probed by various spectroscopic and x-ray scattering methods. The mechanical, thermal and degradative properties of these hybrids can be engineered via nanostructural manipulation. Two forms of compositional gradients were generated within PFSIs: (1) SiO2 nanoparticle cores having organic or metal oxide shells; (2) gradients of inorganic composition across film thicknesses. Gas permeation and liquid sorption can be manipulated via nanostructural tailoring as well as by composition gradients. PFSI SO2 F precursors can be cross linked and inorganic phases introduced via in situ amination and sol-gel reactions for aminopropyltriethoxysilane.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1996
- Accession Number
- ADA316052
Entities
People
- Kenneth A. Maurtiz
- Robert B Moore
Organizations
- University of Southern Mississippi