CONDUCTIVITY AND STRUCTURAL STUDIES OF PEO-NH4SCN ELECTROLYTES

The paper summarizes conductivity and structural studies of PEO-NH4SCN electrolytes of salt concentration identified by the ether oxygen/amm onium cation ratio ranging between 200 and 3. The impedance and DSC st udies are performed during initial heating, cooling and reheating cycl es for all salt concentrations. Contrary to previous results recrystal lization was observed during cooling, which directly followed the init ial heating cycle. Therefore an increase in conductivity observed duri ng cooling can be attributed only to a difference between melting and recrystallization temperatures, the latter of which appears at the low er temperature range. FTIR studies indicate that complexation of ammon ium cation via hydrogen bonding to ether oxygen is the most probable w ay of formation of polymer-salt complex phase. The spectroscopic data suggest that cations are strongly bonded to polyether chains whereas a nions are free to move. Therefore charge transfer seems to be due to t he transport of anionic species.