Accession Number:

ADA316052

Title:

Property Control of (Perfluorinated Ionomer)/(Inorganic Oxide) Composites by Tailoring the Nanoscale Morphology.

Descriptive Note:

Final rept. 1993-1996,

Corporate Author:

UNIVERSITY OF SOUTHERN MISSISSIPPI HATTIESBURG DEPT OF POLYMER SCIENCE

Report Date:

1996-09-01

Pagination or Media Count:

31.0

Abstract:

The morphology and properties of perfluorosulfonate ionomers PFSIs 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 PFSISiO2 and PFSIorganically-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.

Subject Categories:

  • Polymer Chemistry
  • Inorganic Chemistry
  • Organic Chemistry
  • Physical Chemistry
  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE