Composite polymer electrolyte containing ionic liquid and functionalized polyhedral oligomeric silsesquioxanes for anhydrous PEM applications.
Composite polymer electrolyte containing ionic liquid and functionalized polyhedral oligomeric silsesquioxanes for anhydrous PEM applications.
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DOI：
10.1021/am900020w
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发表时间：
2009-05
影响因子：
9.5
通讯作者：
S. Subianto;Mayur K. Mistry;N. Choudhury;N. Dutta;R. Knott
中科院分区：
文献类型：
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作者：
S. Subianto;Mayur K. Mistry;N. Choudhury;N. Dutta;R. Knott
将离子液体（IL）与多功能多面体低聚硅氧烷（POSSs）增强的Nafion膜结合，制备了一种用于无水质子交换膜（PEM）的新型支撑液膜。采用直接磺化法对POSS进行功能化处理，并通过浸润法将磺化后的POSS （S-POSS）掺入到Nafion 117膜中。所得到的杂化膜在Nafion基质和多功能POSS之间表现出强烈的离子相互作用，导致玻璃化转变温度和在极低S-POSS负载（1%）下的热稳定性提高。S-POSS的存在也改善了质子的电导率，特别是在低湿度下，由于其在离子域的限制，质子的电导率显着增加，并通过毛细管冷凝促进水分的吸收。为了实现无水导电性，将IL - 1-丁基-3-甲基咪唑双（三氟甲基磺酰基）亚胺（BMI-BTSI）掺入这些膜中以在无水的情况下提供质子传导。虽然IL的掺入对Nafion膜有塑化作用，但与Nafion 117和Nafion-IL膜相比，含有IL的S-POSS复合膜在高温下具有更高的模量，具有显着更高的质子电导率（150℃，20% IL时为5 mS/cm）。这表明多功能POSS和IL能够通过增强材料内的离子相互作用来协同工作，从而实现理想的质子电导率和这种膜的机械性能。
A new type of supported liquid membrane was made by combining an ionic liquid (IL) with a Nafion membrane reinforced with multifunctional polyhedral oligomeric silsesquioxanes (POSSs) using a layer-by-layer strategy for anhydrous proton-exchange membrane (PEM) application. The POSS was functionalized by direct sulfonation, and the sulfonated POSS (S-POSS) was incorporated into Nafion 117 membranes by the infiltration method. The resultant hybrid membrane shows strong ionic interaction between the Nafion matrix and the multifunctional POSS, resulting in increased glass transition temperature and thermal stability at very low loadings of S-POSS (1%). The presence of S-POSS has also improved the proton conductivity especially at low humidities, where it shows a marked increase due to its confinement in the ionic domains and promotes water uptake by capillary condensation. In order to achieve anhydrous conductivity, the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMI-BTSI) was incorporated into these membranes to provide proton conduction in the absence of water. Although the incorporation of an IL shows a plasticizing effect on the Nafion membrane, the S-POSS composite membrane with an IL shows a higher modulus at high temperatures compared to Nafion 117 and a Nafion-IL membrane, with significantly higher proton conductivity (5 mS/cm at 150 degrees C with 20% IL). This shows the ability of the multifunctional POSS and IL to work symbiotically to achieve the desirable proton conductivity and mechanical properties of such membranes by enhancing the ionic interaction within the material.