Synthesis, Morphology, and Ion Conduction of Polyphosphazene Ammonium Iodide Ionomers

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• 作者：Joshua Bartels ; Andrew Hess ; Huai-Suen Shiau ; Harry R. Allcock ; Ralph H. Colby ; James Runt
• 刊名：Macromolecules
• 出版年：2015
• 出版时间：January 13, 2015
• 年：2015
• 卷：48
• 期：1
• 页码：111-118
• 全文大小：405K
• ISSN：1520-5835

文摘

Anion conducting polyphosphazene ionomer analogues of poly[bis(methoxyethoxyethoxy)phosphazene] (MEEP) were synthesized and their iodide transport properties studied. Polymer bound cations were quaternized with either short alkyl or short ether oxygen chains. X-ray scattering reveals a low q peak near 4 nm^鈥? arising from the backbone鈥揵ackbone spacing between polyphosphazene chains, an ion-related peak at 8 nm^鈥?, and a peak at 15 nm^鈥? corresponding primarily to the amorphous halo of the PEO side chains. Because of the short spacing of the intermediate q peak, the ions are proposed to exist mostly in isolated ion pairs or small aggregates. First-principles calculations combined with dielectric spectroscopy suggest that less than 10% of the ions are in isolated pairs while the remainder participate in quadrupoles or other small aggregates. These ionomers display high values for the high frequency dielectric constant, 蔚_{鈭?/sub> (highest value 蔚鈭?/sub> = 11), due to atomic polarization of the iodide anion. These MEEP-based ionomers have room temperature dc conductivity of order 10^鈥? S cm^鈥? and show potential for application in iodide conducting solar cells if the segmental mobility could be increased.}