376868 Polymer Functionalized Graphene Oxide As Thermally Responsive Ion Permeable Membrane

Monday, November 17, 2014: 12:52 PM
International 9 (Marriott Marquis Atlanta)
Jingmei Shen1, Kai Han1,2, Yi Y. (Chloe) Wu1, Elizabeth Martin3, Cary M. Hayner1, Mayfair C. Kung1, Kenneth R. Shull4 and Harold H. Kung1, (1)Chemical and Biological Engineering, Northwestern University, Evanston, IL, (2)Chemistry and Chemical Engineering, Central South University, Changsha, China, (3)Materials Science and Engineering, Northwestern University, Evanston, IL, (4)Northwestern University, Evanston, IL

A UCST polymer, poly(sulfobetaine) (PMABS), which exhibits upper critical solubility temperature (UCST) behavior, was successfully grown onto graphene oxide sheets with an atom-transfer polymerization process.  The modified graphene oxide sheets could be filtered to form free-standing papers that were then fabricated into a thermally-responsive membrane usable in non-aqueous solutions.  It was tested as a separator in a electrochemical cell, separating a Li foil and a reduced graphene oxide paper as the two electrodes in a configuration that was similar to a half-cell in a Li ion battery.  In the absence of the modified membrane, the specific storage capacitive for Li of the reduced graphene oxide paper increased ~30% when heated from 20oC to 80oC. In contrast, a PMABS-modified separator caused the storage capacity to decrease by over 50%.  The membrane were characterized using SEM, AFM, UV spectroscopy an quartz crystal microbalance. This reversible thermal reduction in ion permeability can be used to mitigate thermal runaway of a Li ion battery, or tune the thermal response of an ion sensor or an electrode, among other applications.

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See more of this Session: Multifunctional Composites
See more of this Group/Topical: Materials Engineering and Sciences Division