Perpendicularly Aligned, Anion Conducting Nanochannels in Block Copolymer Electrolyte Films
Perpendicularly Aligned, Anion Conducting Nanochannels in Block Copolymer Electrolyte Films
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DOI：
10.1021/acs.chemmater.5b04452
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发表时间：
2016-03-08
影响因子：
8.6
通讯作者：
Nealey, Paul F.
中科院分区：
文献类型：
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作者：
Arges, Christopher G.;Kambe, Yu;Nealey, Paul F.
在纳米结构聚合物电解质材料中，将结构和形态与离子导电性等整体传输性能联系起来是一个困难的命题，因为在这种聚合物薄膜中，精确和准确地控制离子结构域的有序性和取向是一个挑战。在这项工作中，通过在基板上进行化学表面修饰，并利用通用的溶剂蒸气退火(SVA)技术，将聚(苯乙烯-嵌段-2-乙烯基吡啶)(PSbP2VP)嵌段共聚物大面积垂直组装到基板表面。在嵌段共聚物组装后，一种新的化学气相渗透反应(CVIR)技术选择性地将2-乙烯基吡啶嵌段转化为2-乙烯基N-甲基吡啶(NMP+X-)基团，这些基团是阴离子电荷载体。所制备的嵌段共聚电解质在选择性地向P2VP嵌段引入离子部分并与其他反离子形式(X-=氯离子、氢氧化物等)进行离子交换后，保持了其取向和有序的纳米结构。所制备的嵌段共聚聚合物电解质膜具有较高的氯离子电导率，在20℃的去离子水中为45ms cm(-1)，是阴离子导电聚合物电解质膜中最高的氯离子电导率。此外，采用化学外延和密度倍增的方法，实现了嵌段共聚电解质的直线片层。设计的方案可以精确和准确地控制纳米结构聚合物电解质薄膜中离子结构域的取向，并为未来研究聚合物电解质结构和离子传输之间的关系提供了一个平台。
Connecting structure and morphology to bulk transport properties, such as ionic conductivity, in nanostructured polymer electrolyte materials is a difficult proposition because of the challenge to precisely and accurately control order and the orientation of the ionic domains in such polymeric films. In this work, poly(styrene-block-2-vinylpyridine) (PSbP2VP) block copolymers were assembled perpendicularly to a substrate surface over large areas through chemical surface modification at the substrate and utilizing a versatile solvent vapor annealing (SVA) technique. After block copolymer assembly, a novel chemical vapor infiltration reaction (CVIR) technique selectively converted the 2-vinylpyridine block to 2-vinyl n-methylpyridinium (NMP+ X-) groups, which are anion charge carriers. The prepared block copolymer electrolytes maintained their orientation and ordered nanostructure upon the selective introduction of ion moieties into the P2VP block and post ion-exchange to other counterion forms (X- = chloride, hydroxide, etc.). The prepared block copolymer electrolyte films demonstrated high chloride ion conductivities, 45 mS cm(-1) at 20 degrees C in deionized water, the highest chloride ion conductivity for anion conducting polymer electrolyte films. Additionally, straight-line lamellae of block copolymer electrolytes were realized using chemoepitaxy and density multiplication. The devised scheme allowed for precise and accurate control of orientation of ionic domains in nanostructured polymer electrolyte films and enables a platform for future studies that examines the relationship between polymer electrolyte structure and ion transport.