SusChEM: Understanding Microwave Interactions to Control Magnetic Nanocrystal Growth from a Single Source Precursor

可持续和具有成本效益的纳米材料生产需要合成方法，这些方法需要少量的能源、快速的反应速度和可回收的成分。对于工业应用，这些合成方法还必须具有可伸缩性和可重复性。微波(MW)化学方法可以达到这些性能要求。杰弗里·斯特鲁斯博士正在研究微波化学，以开发合成尺寸非常小的磁性合金(纳米颗粒)的新方法。他特别感兴趣的是确定微波频率、功率和光学性质对基于普鲁士蓝分子的分子簇热分解速度的影响。普鲁士蓝分子是两种不同的过渡金属，当它们被微波加热分解形成金属合金时，就会产生具有极强磁性的纳米颗粒。这些磁性在许多技术应用中可能是有用的。通过明智地选择兆瓦变量，斯特劳斯博士能够控制纳米级磁铁的成分和大小，根据手头的任务仔细地调整其磁性。这项研究揭示了在双金属纳米颗粒合成中广泛有用的知识，并为纳米金属系统建立了新的合成路线，这些系统是可持续的，可以规模应用于工业应用。这项研究中开发的微波方法学不仅影响到磁学和磁体技术领域，还可能为开发新的催化剂提供途径。斯特劳斯博士的研究具有重大而广泛的影响，因为它在许多层面上都对学生有吸引力。他积极参与培训在STEM领域任职人数不足的学生。他通过亲身参与科学活动，为高中和初中的科学家提供学习经验，与他们互动。Strouse博士在他位于佛罗里达州立大学的公开网站上维护有关微波方法学、微波效应和新材料结构特性的最新细节。在美国国家科学基金会化学系高分子、超分子和纳米化学(MSN)计划的支持下，佛罗里达州立大学的Geoffrey Strouse博士利用微波(MW)化学开发纳米级双金属磁体合金的新合成方法。他的微波合成使用可回收的超临界二氧化碳溶剂和货架稳定的单一来源前体(M‘[M(CN)6])n，其中M’，M是过渡金属，因为它们的磁性以金属合金的形式存在。通过仔细选择微波功率、频率和分子设计，斯特鲁斯博士能够通过选择性地耦合到前体中的电偶极子和磁偶极子来控制反应速度。结合计算研究、介电光谱和磁性测量、仪器设计和纳米双金属合金的材料表征，制备了一系列先进的磁性材料，并研究了微波诱导反应机理。这项研究对工业磁性和催化应用具有重要的更广泛的影响，因为该方法是可扩展的，并可能转化为新材料和更大数量的应用。斯特劳斯博士让年轻学生、科学教师、本科生和研究生参与他的研究，并为STEM领域代表性不足的学生提供指导。他积极参与高中生和中学生的外展活动，并通过实践科学活动为这些学生提供学习经验。他积极维护一个网站，用于传播数据、实验方法和详细的微波辐射分析，公众可以通过华丽的州立大学网页访问该网站。

Sustainable and cost-effective nanomaterial production requires synthesis methods that demand small amounts of energy, rapid reaction rates, and recyclable components. For industrial applications, these synthesis methods must also be scalable and reproducible. Microwave (MW) chemistry methods may achieve these performance demands. Dr. Geoffrey Strouse is investigating microwave chemistry to develop new methods for the synthesis of magnetic alloys with very small dimensions (nanoparticles). He is particularly interested in determining the effects of MW frequency, power, and optical properties on the rate of thermal decomposition of molecular clusters based upon the Prussian blue molecule. Prussian blue molecules have are two different transition metals which, when decomposed by MW heating to form a metal alloy, create a nanoparticle with extremely strong magnetic properties. These magnetic properties may be useful in many technological applications. By judiciously choosing the MW variables, Dr. Strouse is able to control the composition and size of the nanoscale magnet, carefully tailoring its magnetic properties to the task at hand. The research uncovers knowledge that is broadly useful in bimetallic nanoparticle synthesis and establishes new synthetic routes for nano-metal systems that are sustainable and can be scaled to industrial applications. The MW methodology developed in this research impacts not only the fields of magnetism and magnet technology, but may offer routes to new catalysts as well. Dr. Strouse's research has significant broader impacts, since it is attractive to students at many levels. He is actively involved in training students underrepresented in the STEM fields. He interacts with high school and middle school scientists by providing learning experiences for them with hands on scientific activities. Dr. Strouse maintains up-to-date details on MW methodolgy, microwave effects, and structural properties of the new materials on his publically-accessible website at Florida State University.Supported by the Macromolecular, Supramolecular and Nanochemistry (MSN) Program of the Chemistry Division at NSF, Dr. Geoffrey Strouse of Florida State University employs microwave (MW) chemistry to develop new synthesis methodologies for nano-scaled bi-metallic magnet alloys. His MW synthesis uses recyclable supercritical CO2 solvent and a shelf-stable single-source precursor, (M'[M(CN)6])n, where M', M are transition metals chosen for their magnetic properties in the metal alloy form. By careful selection of microwave power, frequency, and molecular design, Dr. Strouse is able to control the rate of the reaction by selectively coupling to electric and magnetic dipoles in the precursor. In conjunction with computational studies, dielectric spectroscopy and magnetic measurements, instrumental design, and materials characterization of the nanosized bi-metallic alloys are used to fabricate a series of advanced magnetic materials and to investigate MW-induced reaction mechanisms. The research has significant broader impact on industrial magnetic and catalytic applications, since the methodology is scalable and may be translated to new materials and larger quantity applications. Dr. Strouse involves young students, science teachers, undergraduate and graduate students in his research, and serves as a mentor of students underrepresented in STEM fields. He is actively engaged in outreach to high school and middle school students, and provides learning experiences for these students with hands-on science activities. He actively maintains a website for dissemination of data, experimental methodology, and detailed MW analysis, accessible to the general public through Florid State University web pages.