Nanobipolar junction interfaces for ion-exchange membrane and resin materials for electrochemical systems

1703307随着提供零排放电力的可再生能源的日益整合，电化学技术可能很快就会超越电动汽车，也会影响水处理和化学品生产。电化学电池的一个熟悉的例子是电池，其中电子从储存电化学能的化学物质中释放出来。电子通过受控路径行进以完成电路并提供电力。 由于电子带负电荷，带正电荷的离子（例如，电池酸）必须同时匡威物理屏障以保持电荷中性。固态聚合物电解质隔膜提供这些受控且分离的同时引导电子和离子的路径。 在腐蚀性和反应性很强的环境中，这种隔膜必须具有化学、电化学、热和机械稳定性。为了使不需要的能量和功率损失最小化，还必须使电子转移的阻力最小化，这可以通过分离器的分子级设计来实现。 该项目的重点是分子设计和优化一类相对未开发的聚合物电解质隔膜，称为双极膜。 双极膜在用于水裂解电化学反应的共享界面处结合带正电荷和带负电荷的分子的接合点。电化学水分解能够将瞬时可再生能源转化为化学能，用于长期储存。该项目将在分子水平上设计双极结，以最大限度地减少能量损失，并对许多电化学技术产生潜在影响。该项目旨在通过将双极结中的界面面积与水裂解动力学和水和离子物种的传质相关阻力相关联，克服双极膜当前的一些局限性。揭示这种相关性预计将产生较低的电阻双极膜，其转化为较低的能量足迹电化学反应器-分离器工艺。该项目的中心假设假定，水解离的细胞超电位和双极结界面面积之间存在反比、相称的关系。测试中心假设将通过经由两种方法制造精确定义的双极结接口来完成：i.）通过嵌段共聚物光刻在衬底表面上构建2D双极结，以及ii.）通过由嵌段共聚物模板提供的纳米结构模具纳米图案化本体膜表面。预期的结果将揭示双极结界面的显着结构特征如何支配电化学电池的性能时，分裂水。 最后，该项目将有助于培训未来的STEM劳动力，以应对水-能源关系中的未来挑战，并将激发8年级和9年级学生对数学的兴趣，并开展宣传活动，说明代数原理在材料设计中的实用性。

1703307 ArgesWith increasing integration of renewable energy sources that provide emission-free electrical power, electrochemical technologies may soon extend beyond electric automobiles to also impact water treatment and chemical production. A familiar example of an electrochemical cell is the battery, in which electrons are released from a chemical species that has stored electrochemical energy. The electrons travel via a controlled pathway to complete the electrical circuit and provide electricity. As the electrons are negatively charged, positively charged ions (for example, battery acid) must simultaneously converse a physical barrier to maintain charge neutrality. A solid-state polymer electrolyte separator provides these controlled and separate pathways that simultaneously channel electrons and ions. In an environment that is often quite corrosive and reactive, this separator must be chemically, electrochemically, thermally, and mechanically stable. To minimize unwanted energy and power losses, resistances to the transfer of electrons must also be minimized, which can be accomplished via molecular-level design of the separator. This project focuses on molecular design and optimization of a relatively unexplored class of polymer electrolyte separators, called bipolar membranes. A bipolar membrane incorporates a junction of positively and negatively charged molecules at a shared interface for water splitting electrochemical reactions. Electrochemical water splitting enables conversion of transient renewable power to chemical energy for long term storage. This project will engineer the bipolar junction on a molecular-level scale to minimize energy losses, with potential impact to a number of electrochemical technologies.This project aims to overcome some of the current limitations of bipolar membranes by correlating interfacial area in the bipolar junction to water-splitting kinetics and mass transport related resistances of water and ion species. Uncovering this correlation is anticipated to yield lower resistant bipolar membranes that translate to lower energy footprint electrochemical reactor-separator processes. The central hypothesis of the project posits that an inverse, commensurate relationship exists between cell overpotential for water dissociation and bipolar junction interfacial area. Testing the central hypothesis will be accomplished by fabricating precisely defined bipolar junction interfaces via two approaches: i.) constructing 2D bipolar junctions on substrate surfaces through block copolymer lithography and ii.) nanopatterning bulk membrane surfaces through nanostructured molds afforded from block copolymer templates. The expected outcomes will reveal how the salient structural features of bipolar junction interfaces govern electrochemical cell performance when splitting water. Finally, the project will contribute to the training of a future STEM workforce prepared to address future challenges in the water-energy nexus, and it will spark 8th and 9th grade students' interest in math with outreach activities that illustrate the utility of algebra principles to materials design.