Functional Patchy Nanoparticles by Interfacial Engineering

摘要金属纳米颗粒通常具有有机盖层，形成有机壳-金属核结构。因此，材料的性能和功能在很大程度上取决于这两种成分。在材料研究部固态和材料化学项目的支持下，该研究项目的重点是开发制备一类特殊纳米颗粒材料的有效程序，其中有机配体和金属成分可以以一种空间可控的方式独立地结合到纳米颗粒中。这为进一步操纵纳米粒子的结构和性质提供了一种独特的方法。那不勒斯纳米颗粒被用作最初的说明示例，类似于分层的那不勒斯蛋糕，在两极和赤道环上具有结构独特的有机/金属成分。这些纳米颗粒可用于制备更复杂的纳米颗粒材料和结构，以及用于燃料电池阴极的关键反应氧的电催化还原。研究活动与各种教育努力紧密结合，从对研究生、本科生和高中生等不同学生研究人员的现场培训。技术摘要：本研究项目的具体目的是开发基于有意界面工程的有效方案，用于制备具有三斑块结构的那不勒斯纳米颗粒，这些纳米颗粒不仅具有有机覆盖层，而且具有金属芯。这是建立在PI实验室先前成功制备两亲性Janus纳米粒子的基础上的。在目前的研究项目中，重点是那不勒斯纳米颗粒，在纳米颗粒的两极和赤道环上表现出明显不同的化学功能。同时，利用纳米颗粒与金属硫酸盐配合物之间的电交换反应，原有的单金属纳米颗粒核可以转化为双金属甚至三金属，第二金属和第三金属也不对称地分布在纳米颗粒核上。有机盖层和金属芯的制备和独立操作可用于进一步和更复杂的纳米颗粒化学功能化。这些基本的见解预计将进一步推进我们对控制纳米结构材料有组织组装的机制的理解。

Non-Technical AbstractMetal nanoparticles are generally stabilized with an organic capping layer, forming an organic shell-metal core structure. The materials properties and functions are therefore largely determined by these two components. With support from the Solid State and Materials Chemistry Program in the Division of Materials Research, this research project is focused on the development of effective procedures for the preparation of a special class of nanoparticle materials where the organic ligands as well as the metal components may be independently incorporated into the nanoparticles in a spatially controlled manner. This provides a unique way to further manipulate the nanoparticle structures and properties. Neapolitan nanoparticles are used as the initial illustrating examples, analogous to a layered Neapolitan cake with structurally distinct organic/metal components at the two poles and at the equatorial ring. These nanoparticles may be used to prepare more complicated nanoparticle materials and structures, and for electrocatalytic reduction of oxygen, a critical reaction at fuel cell cathode. The research activities are intimately integrated with various educational efforts, from on-hands training of diverse student researchers including graduate students, undergraduate students and high-school students. Technical AbstractThe specific aim of this research project is to develop effective protocols based on deliberate interfacial engineering for the preparation of Neapolitan nanoparticles with a tri-patchy structure not only of the organic capping layers but also of the metal cores. This is built upon the prior success of the PI's laboratory in the preparation of amphiphilic Janus nanoparticles. In the present research project the focus is on Neapolitan nanoparticles that exhibit distinctly different chemical functionalities at the two poles and on the equatorial ring of the nanoparticles. Concurrently, the original monometallic nanoparticle cores may be converted to bimetallic or even trimetallic ones by taking advantage of galvanic exchange reactions between the nanoparticles and metal-thiolate complexes, with the second and third metals also distributed asymmetrically on the nanoparticle cores. The ready and independent manipulation of both the organic capping layers and the metal cores into segregated patches may be exploited for further and more complicated chemical functionalization of the nanoparticles. The fundamental insights are anticipated to further advance our understanding of the mechanisms that control the organized assembly of nanostructured materials in general.