(163ag) Nanoscale Morphology of Ionomer Systems
AIChE Annual Meeting
2006
2006 Annual Meeting
Materials Engineering and Sciences Division
Poster Session: Materials Engineering and Sciences Division
Monday, November 13, 2006 - 6:30pm to 9:00pm
The morphology of poly(styrene-ran-styrene
sulfonate) (P(S-SSx)) ionomers has been investigated extensively by
several research groups.[1-3] However,
only our 2001 publication has applied the method of scanning transmission
electron microscopy (STEM) to probe the size, shape and spatial distribution of
the ionic aggregates is these ionomers.[4]
This analytical electron microscopy method minimizes phase contrast that
can obscures nano-scale features and accentuates differences in atomic
number. We recently reported
quantitative agreement between results obtained by STEM and by small angle
x-ray scattering (SAXS) in a Cu-neutralized poly(styrene-ran-methacrylic acid) (SMAA)
ionomer.[5] This is the first report of
quantitative agreement regarding the size of spherical ionic aggregates as
determined by an imaging and a scattering method. We now apply these STEM and SAXS methods to characterize the
morphologies of P(S-SSx) random copolymers neutralized with various
cations. Combining direct imaging and
X-ray scattering of sulfonated polystyrene systems will resolve uncertainties
in the morphologies of these materials and serve as a guide to explain its many
unique physical properties.
[1] Yarusso, D.; Cooper, S. L., Macromolecules 1983, 16, 1871.
[2]O'Connell,
E.M.; Root; T.W.; Cooper, S.L., Macromolecules 1995, 11, 3995.
[3] Ding, S.Y.; Hubbard, S.R.;
Hodgson, K.O; Register, R.R.; Cooper, S.L., Macromolecules, 1988,
21, 1698.
[4] Kirkmeyer, B. P.; Weiss, R. A.;
Winey, K. I., Journal of Polymer Science:
Part B: Polymer Physics 2001,
39, 477.
[5] Benetatos, N.M.; Winey, K.I., Macromolecules,
submitted.