Self-Assembling Redox-Mediators

CBET - 1263970自组装氧化还原介体Abbott，Nicholas L. 威斯康星大学麦迪逊分校智力优势：该研究旨在广泛推进氧化还原活性表面活性剂的分子水平设计，这些表面活性剂有可能在电化学和光电化学系统中作为自组装氧化还原介体。该研究的第一个目标是专注于表面活性剂，包括氧化还原活性基团二茂铁，并寻求对二茂铁氧化态的变化如何影响的基本理解。氧化还原活性表面活性剂在表面（例如，电极表面）。为此，表面等离子体共振，本研究将结合原子力显微镜和电位阶跃计时库仑法来检验二茂铁基两亲物在化学功能化固体表面上依赖于氧化态的自组装的三个关键假设。本研究将揭示表面活性剂在表面上的平衡和动力学性质的基本见解。本研究的第二个关键目标是了解依赖于氧化态的自组装是如何发生的。氧化还原活性表面活性剂在表面（如在目标中阐明的）的氧化影响这些表面活性剂在电极处的氧化的前向和后向速率。前向和后向电化学转化的速率，在第二个目标下进行的研究将寻求建立基于自组装氧化还原介体的原理，所述自组装氧化还原介体可用于最小化太阳能驱动装置中的不期望的重组或逆反应，用于光致发光和水裂解。在光阳极处氧化介体的还原）在确定中起中心作用。染料敏化太阳能电池和光解水过程的效率循环伏安法、电位阶跃计时库仑法和暗电流测量将与第一个研究目标中出现的知识相结合，以阐明基于自组装的物理过程，这些过程可用于调节氧化还原表面活性剂的氧化/还原速率。以确定的速率和在表面上的指定位置转换分子的两亲性的能力有可能通过使新型实验能够促进我们对表面活性剂体系的动态和平衡性质的理解来广泛影响表面活性剂科学。特别是氧化还原活性表面活性剂在表面（电极）的氧化还原速率的测量将为复杂表面活性剂体系在表面的动力学提供基本的见解 由该研究产生的知识的技术潜力也是巨大的。具体地，鉴定动力学上快速但在电极处表现出低复合速率的氧化还原介体仍然是一个未解决的挑战，如果解决了该挑战，将提高一系列光驱动技术的效率。这些太阳能技术提供了提供可持续的电能来源以及太阳能燃料（e.g.as从水的分解获得）的潜力，这两者都降低了对碳基能源的依赖和更广泛地CO2的排放。电化学控制分子的两亲性的能力将使控制表面活性剂的现象，在一系列的技术背景，包括分离，药物输送，能量收集材料的合成和生物分子界面的设计。在这个项目中描述的研究也提供了令人兴奋的机会，通过项目，联合收割机表面活性剂科学，胶体化学，界面科学和这些学生还将获得参与两项国际合作（与以色列和日本的合作者）的不寻常机会。

CBET - 1263970 Self-Assembling Redox-MediatorsAbbott, Nicholas L. University of Wisconsin-Madison Intellectual Merit: The research seeks to broadly advance the molecular level design of redox active surfactants that have the potential to serve as self assembling redoxmediators in electrochemical and photoelectrochemical systems. The first goal of the research isfocused on surfactants that incorporate.The redox active group ferrocene and seeks to develop a fundamental understanding of how changes in the oxidation state of the ferrocene impacts. The self assembly of the redox active surfactants at surfaces (e.g.,electrode surfaces). To this end,surface plasmon resonance,atomic force microscopy and potential step chronocoulometry will be combined to test three key hypotheses regarding oxidation state dependent self assembly of ferrocenyl amphiphiles on chemically functionalized solid surfaces Fundamental insights into The equilibriumand dynamic properties of surfactants at surfaces will emerge from the research A second key goal of The research is to understand how the oxidation state dependent self assembly of redox active surfactants at surfaces(as elucidated in goal) impacts the forward and backward rates of oxidation of these surfactants at electrodes Building from preliminary data indicating that incorporation of redox probes into self assembling molecules can substantially change. The rates of forward and backward electrochemical transformations,research conducted under the second goal will seek to establish principles based on self assembling redox mediators that can be used to minimize undesirable recombination or back reactions in solar energy driven devices for photovoltaics and water splitting Such back reactions(e.g.,reduction of an oxidized mediator at a photoanode) play a central role in determining. The efficiency of both dye sensitized solar cells and photolytic processes for water splitting Cyclic voltammetry,potential step chronocoulometry and darkcurrent measurements will be combined with knowledge emerging from the first research goal to elucidate physical processes based on self assembly that can be exploited to regulate the rates ofoxidation/reduction of redox surfactantsBroader Impacts: The ability to transform the amphiphilicity of molecules at defined rates and at specified locations on surfaces has the potential to broadly impact surfactant science by enabling new types of experiments that will advance our understanding of the dynamic and equilibrium properties of surfactant systems. In particular measurement of rates of oxidation and reduction ofredox active surfactants at surfaces (electrodes)will provide fundamental insights into the dynamics of complex surfactant systems at surfaces technological potential of the knowledge to be generated by this research is also substantial Specifically,identification of redox mediators that are kinetically fast yet exhibit low rates of recombination at electrodes remains an unresolved challenge that,if solved, would advance the efficiency of a range of light driven technologies. These solar technologies offer the potential to provide sustainable sources of electrical energy as well as solar fuels(e.g.as obtained from splitting of water) both lowering reliance of carbon based energy sources and emissions of CO2 More broadly. The ability to electrochemically control the amphiphilicity of molecules will enable control of surfactant based phenomena in a rangeof technological contexts including separations drug delivery energy harvesting materials synthesis and design of biomolecular interfaces.The research described in this project also provides exciting opportunities for the education of graduateand undergraduate students through projects that combine surfactant science colloid chemistry interface science and electrochemical engineering.These students will also be presented with the unusual opportunity of being involved in two international collaborations (with collaborators in Israel and Japan)