S. Sunderrajan et al., Propane and propylene sorption in solid polymer electrolytes based on poly(ethylene oxide) and silver salts, J MEMBR SCI, 182(1-2), 2001, pp. 1-12
The sorption of propylene and propane in solid polymer electrolytes based o
n blends of poly(ethylene oxide) (PEO) and silver nitrate, AgNO3, silver tr
iflate, AgCF3SO3, silver trifluoroacetate, AgCF3CO2. or silver tetrafluorob
orate, AgBF4, are reported. These solid polymer electrolytes exhibit prefer
ential sorption for propylene over propane due to complexation of propylene
with silver ions in the polymer matrix and reduced propane solubility in t
he solid polymer electrolyte films relative to that in PEO alone. The order
of olefin solubility in blends containing 1 mol of silver ions per mole of
ethylene oxide (EO) units is: AgBF4 >> AgCF3SO3 > AgCF3CO2 > AgNO3. At 35
degreesC and 40 cmHg pressure, a PEO/AgBF4 film containing 1 mol of silver
ions per mole of EO sorbed 5.3 g propylene but only 0.083 g propane per 100
g of solid polymer electrolyte. AgBF4 is highly soluble in PEO and complet
ely disrupts polymer crystallinity even at low salt concentration (approxim
ately 10 wt.%) without significantly altering the glass transition temperat
ure. Other silver salts (e.g. AgNO3) do not dissolve completely in PEO and
are much less effective at promoting enhanced olefin solubility. (C) 2001 E
lsevier Science B.V. All rights reserved.