CAREER: Single Particle Visualization of Chemical Processes During Multimetallic Nanocrystal Synthesis

在美国国家科学基金会化学部大分子、超分子和纳米化学（MSN）项目的支持下，马里兰大学帕克分校的泰勒·沃尔（Taylor Woehl）将对合成金属纳米颗粒的化学过程进行基础研究。金属纳米颗粒是一种十亿分之一米大小的小颗粒，由不同金属混合而成。金属纳米颗粒在化学传感器、光学材料和加速化学反应的催化剂方面具有潜在的应用前景。更好地了解金属纳米颗粒的合成过程对控制其性能具有重要意义。参与该项目的学生将获得使用最先进仪器合成和表征纳米粒子的经验。这个职业奖将支持科幻小说中的纳米科学（NS2F）项目，该项目将通过科幻小说的窗口向那些通常不会寻求校外STEM（科学、技术、工程和数学）活动的高中生（包括那些来自代表性不足的少数群体的学生）介绍纳米科学的概念。该计划旨在提高高中生的科学素养，并为他们提供积极的科学榜样。在这个项目中，Taylor Woehl博士和他的团队将建立一种方法，通过电子束辐射分解来控制溶液化学，以探测在金属硫代酸前体合成多金属纳米颗粒的溶液合成过程中形成的反应中间体。相关液相电子显微镜和质谱将用于描述和可视化分子和纳米级反应中间体，包括金属配体配合物，金属纳米团簇和晶体核，在单个实体尺度上。通过这些实验，研究小组旨在阐明连接分子尺度（例如，纳米簇化学）和纳米尺度化学（例如，晶体成核和生长）的反应机制，并开发新的纳米晶体形成理论，以解释“非经典”效应，从而能够利用反应中间体来控制多金属纳米颗粒的性质。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 of the Division of Chemistry at the National Science Foundation, Taylor Woehl at the University of Maryland-College Park will conduct fundamental research on the chemical processes involved in the synthesis of metal nanoparticles, small particles one billionth of a meter in size containing a mixture of different metals. Metal nanoparticles have potential applications as chemical sensors, optical materials, and catalysts in accelerating chemical reactions. A better understanding of the synthetic processes is important for controlling the properties of metal nanoparticles. Students working on this project will gain experience synthesizing and characterizing nanoparticles using state of the art instruments. This CAREER award will support The Nanoscience in Science Fiction (NS2F) program, which will introduce high school students that would not normally seek out extramural STEM (science, technology, engineering and mathematics) activities, including those from under-represented minority groups, to concepts in nanoscience through the window of science fiction. The program aims to improve science literacy of high school students and provide them with positive science role models.In this project, Dr. Taylor Woehl and his team will establish methods to controllably drive solution chemistry with electron beam radiolysis to probe the reaction intermediates formed during solution phase synthesis of multi-metallic nanoparticles from metal thiolate precursors. Correlative liquid phase electron microscopy and mass spectrometry will be used to delineate and visualize molecular and nanoscale reaction intermediates, including metal-ligand complexes, metal nanoclusters, and crystal nuclei, on the single entity scale. Through these experiments, the research team aims to elucidate reaction mechanisms connecting molecular scale (e.g., nanocluster chemistry) and nanoscale chemistry (e.g., crystal nucleation and growth) and to develop new nanocrystal formation theories to account for ‘non-classical’ effects that will enable harnessing reaction intermediates to control the properties of multimetallic nanoparticles.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.