Solvent tunable multi-block ionomer morphology and its relationship to modulus, water swelling, directionally dependent ion transport, and actuator performance
Solvent tunable multi-block ionomer morphology and its relationship to modulus, water swelling, directionally dependent ion transport, and actuator performance
复制标题
溶剂可调多嵌段离聚物形态及其与模量、水膨胀、方向依赖性离子传输和执行器性能的关系
DOI：
10.1016/j.polymer.2016.09.055
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发表时间：
2016
期刊：
影响因子：
4.6
通讯作者：
C. Cornelius
中科院分区：
文献类型：
--
作者：
Wenjian Zheng;C. Cornelius
磺化五嵌段离聚物（SBI）溶剂流延膜的离子域空间排列从随机过渡到连接良好的层状/六方结构。这种微相分离的形态是可调的，并且相关的溶液性质从非极性环己烷/庚烷（CH）过渡到极性四氢呋喃（THF）。观察到的形态变化，其特征在于使用透射电子显微镜（TEM）和小角X射线散射（SAXS）。SAXS显示，膜内平均磺化畴间间距不对称增加。例如，溶剂浇铸的SBI-H+膜畴间间距从使用CH的30.8nm变为使用THF的43 nm。这种层状/六边形形态导致两倍的吸水率从23重量%增加到46重量%，并且质子传导率从4.5 mS/cm提高到47.8 mS/cm。离子聚合物-金属复合材料（IPMC）的致动性能是形态依赖。具有随机形态的膜具有小的致动位移和缓慢的弯曲速度。然而，连接良好的离子域能够实现快速且大的弯曲运动。
Sulfonated penta-block ionomer (SBI) solvent cast film's ion domain spatial arrangement transitioned from random into well-connected lamellar/hexagonal structures. This micro-phase separated morphology was tunable and associated solution properties transitioning from nonpolar cyclohexane/heptane (CH) to polar tetrahydrofuran (THF). The observed morphology changes were characterized using transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). SAXS revealed that average sulfonated inter-domain spacing increased asymmetrically within the film. For example, solvent cast SBI-H+film inter-domain spacing changed from 30.8 nm using CH to 43 nm with THF. This lamellar/hexagonal morphology led to a two-fold water uptake increase from 23 wt% to 46 wt%, and an order-of-magnitude proton conductivity improvement from 4.5 mS/cm to 47.8 mS/cm. Ionomeric polymer-metal composite (IPMC) actuation performance was morphology dependent. The film with a random morphology had small actuation displacement with slow bending speed. However, well-connected ion domains enabled rapid and large bending motions.