Nanocrystal Conversion Pathways for the Synthesis of Multimetallic Nanostructures

在化学学部大分子、超分子和纳米化学（MSN）项目的支持下，印第安纳大学布卢明顿分校的Sara Skrabalak教授将开发制造纳米尺度多金属材料的新方法。纳米级尺寸的金属颗粒具有不同于块状材料的迷人特性。例如，大块金呈现为有光泽的黄色，而纳米级金可以根据颗粒大小和形状呈现许多不同的颜色，从而产生了彩色玻璃的绚丽色彩。金属颗粒的纳米级特性现在正被用于促进可持续性、安全性、健康等方面的技术。然而，由两种或两种以上金属组成的纳米级粒子的一般合成还远远不够发达。Skrabalak小组的目标是开发具有明确结构和组成特征的可预测和可推广的多金属纳米颗粒合成。该项目将在一个包容的环境中为研究生提供强有力的培训。此外，这项研究将与广泛的教育和推广活动相结合，以促进对纳米尺度材料的理解，包括通过与当地艺术家和非科学家合作，通过“十的幂”概念探索尺度的重要性。Skrabalak教授和她的学生将与印第安纳州布卢明顿艺术委员会合作，确定一个地点和艺术家来创作一幅公共壁画，探索大小和规模及其对公共生活的重要性。公众探索这一主题的活动将在壁画的首次亮相和随后的推广活动中使用。多金属纳米颗粒的合成将从已知的纳米颗粒开始，然后通过物理和化学方法将其转化为更复杂的纳米颗粒。纳米颗粒的转化途径将主要集中在两类纳米颗粒上。首先，高熵合金金属纳米粒子——由五种或五种以上元素组成的多元素单相材料，其原子比例相似——将通过加热core@shell纳米粒子来促进相互扩散。它们形成的机制将通过监测晶体相和元素分布的变化来确定。新的作文也将成为目标。其次，通过多金属纳米颗粒与金属前驱体之间的电替换，合成具有不同金属畴的纳米颗粒异质结构。阐明不同纳米颗粒异质结构形成的机制，以实现原子级和纳米级结构的集成。这些复合纳米粒子的组成和结构特性也将被研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry (MSN) Program in the Division of Chemistry, Professor Sara Skrabalak at Indiana University – Bloomington will develop new ways of making multimetallic materials with nanoscale dimensions. Metal particles with nanoscale dimensions have fascinating properties that differ from bulk materials. For example, bulk gold appears as a lustrous yellow color while nanoscale gold can appear many different colors depending on particle size and shape, having given rise to the brilliant colors of stained glass. The nanoscale properties of metal particles are now being leveraged in technologies that promote sustainability, security, health, and more. However, general syntheses for nanoscale particles composed of two or more metals are far less developed. The Skrabalak group aims to develop predictable and generalizable syntheses for multimetallic nanoparticles with defined structural and compositional features. This project will provide robust training for graduate students in an inclusive environment. In addition, this research will be coupled with broad educational and outreach initiatives that promote understanding of nanoscale materials, including exploration of the importance of scale through the “Powers of Ten” concept with local artists and non-scientists. Professor Skrabalak and her students will work with the Art Commission of Bloomington, Indiana to identify a site and artist for the creation of a public mural that explores size and scale and their importance to public life. Activities for the public’s exploration of this topic will be developed for use during the mural’s debut and subsequent outreach events.The synthesis of multimetallic nanoparticles will start with known nanoparticles, which will then be converted into more complex nanoparticles by physical and chemical methods. The nanoparticle conversion pathways will focus on two nanoparticle classes. First, high entropy alloy metal nanoparticles – multi-element, single-phase materials consisting of five or more elements in similar atomic ratios – will be synthesized by heating core@shell nanoparticles to facilitate interdiffusion. The mechanism that accounts for their formation will be determined by monitoring changes in crystal phase and elemental distribution. New compositions also will be targeted. Second, nanoparticle heterostructures with different metal domains will be synthesized by galvanic replacement between multimetallic nanoparticles and metal precursors. The mechanism that accounts for the formation of different nanoparticle heterostructures will be elucidated to achieve particles with integrated atomic and nanoscale architectures. The compositional and structural properties of these complex nanoparticles will also be studied.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.