TY - JOUR
AU - S. S Piril Ertem
AU - Benjamin R Caire
AU - Tsung-Han Tsai
AU - Di Zeng
AU - Melissa A Vandiver
AU - Ahmet Kusoglu
AU - Soenke Seifert
AU - Ryan C Hayward
AU - Adam Z Weber
AU - Andrew M Herring
AU - E. E Bryan Coughlin
AU - Matthew W Liberatore
AB - <p><span>Anion exchange membranes (AEMs) are a promising class of materials for applications that require selective ion transport, such as fuel cells, water purification, and electrolysis devices. Studies of structure–morphology–property relationships of ion-exchange membranes revealed that block copolymers exhibit improved ion conductivity and mechanical properties due to their microphase-separated morphologies with well-defined ionic domains. While most studies focused on symmetric diblock or triblock copolymers, here, the first example of a midblock quaternized pentablock AEM is presented. A symmetric ABCBA pentablock copolymer was functionalized to obtain a midblock brominated polymer. Solution cast films were then quaternized to obtain AEMs with resulting ion exchange capacities (IEC) ranging from 0.4 to 0.9 mmol/g. Despite the relatively low IEC, the polymers were highly conductive (up to 60 mS/cm Br</span><span>−</span><span>at 90 °C and 95%RH) with low water absorption (&lt;25 wt %) and maintained adequate mechanical properties in both dry and hydrated conditions. X-ray scattering and transmission electron microscopy (TEM) revealed formation of cylindrical non-ionic domains in a connected ionic phase.&nbsp;</span></p>
BT - Journal of Polymer Science Part B: Polymer Physics
DA - 01/2017
DO - 10.1002/polb.24310
IS - 7
LA - eng
N2 - <p><span>Anion exchange membranes (AEMs) are a promising class of materials for applications that require selective ion transport, such as fuel cells, water purification, and electrolysis devices. Studies of structure–morphology–property relationships of ion-exchange membranes revealed that block copolymers exhibit improved ion conductivity and mechanical properties due to their microphase-separated morphologies with well-defined ionic domains. While most studies focused on symmetric diblock or triblock copolymers, here, the first example of a midblock quaternized pentablock AEM is presented. A symmetric ABCBA pentablock copolymer was functionalized to obtain a midblock brominated polymer. Solution cast films were then quaternized to obtain AEMs with resulting ion exchange capacities (IEC) ranging from 0.4 to 0.9 mmol/g. Despite the relatively low IEC, the polymers were highly conductive (up to 60 mS/cm Br</span><span>−</span><span>at 90 °C and 95%RH) with low water absorption (&lt;25 wt %) and maintained adequate mechanical properties in both dry and hydrated conditions. X-ray scattering and transmission electron microscopy (TEM) revealed formation of cylindrical non-ionic domains in a connected ionic phase.&nbsp;</span></p>
PY - 2017
SP - 612 
EP -  622
ST - J. Polym. Sci. Part B: Polym. Phys.
T2 - Journal of Polymer Science Part B: Polymer Physics
TI - Ion transport properties of mechanically stable symmetric ABCBA pentablock copolymers with quaternary ammonium functionalized midblock
VL - 55
ER -