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

Personal Author(s) : Maurtiz, Kenneth A. ; Moore, Robert B.

PDF Url : ADA316052

Report Date : SEP 1996

Pagination or Media Count : 31

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.

Descriptors :   *COMPOSITE MATERIALS, *IONOMERS, *FLUORINATION, *INORGANIC MATERIALS, METALS, THICKNESS, SCATTERING, PERMEABILITY, SPECTROSCOPY, LIQUIDS, SILICON DIOXIDE, MORPHOLOGY, FILMS, PHASE, GASES, X RAY DIAGNOSTICS, OXIDES, TEMPLATES, X RAY SCATTERING, SULFONATES, MEMBRANES, SULFUR, SORPTION, GRADIENTS, FLUORINE COMPOUNDS, ALKOXY RADICALS, SOL GEL PROCESSES.

Subject Categories : Polymer Chemistry
      Inorganic Chemistry
      Organic Chemistry
      Physical Chemistry
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE