CAREER: Investigating Surface Ligand Doping, Organization and Valency in Semiconductor Nanocrystal Quantum Dots: A Bridge Between Nano Chemistry Research and Education

化学部的大分子、超分子和纳米化学（MSN）计划支持爱荷华州州立大学哈维尔·贝拉教授的职业奖研究和教育计划。Vela教授和他的学生们研究了新的表面配体掺杂策略，这些策略能够控制功能化程度或每电子单位的化合价。作为这项工作的一部分，Vela教授的小组将研究表面改性导致的配体组织，表面化学和生物学性质的变化。控制每纳米粒子的官能化程度仍然是胶体半导体中未解决的挑战。表面改性通常通过与过量的羧酸酯或胺封端的硫醇进行配体交换来进行。然而，这种方法无法控制表面改性的程度。为了解决这一问题，Vela教授和他的学生将合成表面掺杂的量子点，并表征其表面微观结构，合成用于表面掺杂的模块化功能多齿配体并研究其与量子点的配体交换行为，并探索表面掺杂量子点用于镧系元素光学活化和稀土定量配给。这项研究将对我们微调能量和电荷转移供体和受体的数量和相对构型的能力产生积极影响，为无机-有机-溶剂界面上的激子衰减途径提供前所未有的控制。这项研究的成功将为制造，组装和发现用于成像，生物，能源和催化的功能纳米材料提供强有力的策略。例如，特定官能团的表面覆盖程度将影响微球的表面亲和力和渗透性，以及其定位、渗透和转运穿过生物组织和亚细胞结构的能力。此外，表面掺杂纳米晶体的先进表征将进一步我们的理解，表面配体组织和这如何影响光电性能。这项建议的教育目标是通过在爱荷华州州立大学举办一系列大学范围的纳米研讨会和纳米化学课程，缩小纳米技术研究和教育方面的差距，并通过为西班牙裔和拉丁裔/a学生和家庭举办各种招聘和双语活动来扩大参与。每周一次的研讨会和正式课程将促进跨部门纳米技术研究人员之间的互动和交流。通过用两种语言交流科学，Vela教授将直接解决日益增长的人口问题，以提高对纳米科学的认识和宣传，作为改善社区、国民经济和环境的一种方式。

The Macromolecular, Supramolecular, and Nanochemistry (MSN) program of the Division of Chemistry supports the CAREER Award's research and education program of Prof. Javier Vela at Iowa State University. Prof. Vela and his students investigate new surface ligand doping strategies that enable to control the degree of functionalization or valency per nanocrystal. As part of this effort, Prof. Vela's group will investigate the changes in ligand organization, surface chemistry and nanocrystal properties that result from surface modification. Controlling the degree of functionalization per nanocrystal remains an unsolved challenge in colloidal semiconductors. Surface modification is routinely performed by ligand exchange with excess carboxylate- or amine-terminated thiols. However, this method fails to control the extent of surface modification. To solve this problem, Prof. Vela and his students will synthesize surface-doped quantum dots capped with chemically-active native ligands and characterize their surface microstructures, synthesize modular functional polydentate ligands for surface-doping and study their ligand exchange behavior with quantum dots, and explore the use of surface-doped quantum dots for lanthanide optical activation and rationing of rare earths. This research will positively impact our ability to fine-tune the number and relative configuration of energy- and charge-transfer donors and acceptors, providing unprecedented control over exciton decay pathways across the inorganic-organic-solvent interface.Success of this research will result in powerful strategies to fabricate, assemble and discover functional nanomaterials for imaging, biology, energy and catalysis. For example, the extent of surface coverage by a particular functional group will impact a nanocrystal's surface affinity and permeability, and its ability to localize, penetrate, and be transported across biological tissues and subcellular structures. In addition, advanced characterization of surface-doped nanocrystals will further our understanding of surface-ligand organization and of how this affects optoelectronic properties. The educational goals of this proposal are to close gaps in nanotechnology research and education by introducing a university-wide nano seminar series and a nanochemistry course at Iowa State University, and to broaden participation via diverse recruiting and bilingual activities for Hispanic and Latino/a students and families. A weekly seminar and a formal course will promote interactions and facilitate exchanges among nanotechnology researchers across departments. By communicating science in two languages, Prof. Vela will directly address a growing demographic to raise awareness and advocacy for nanoscience as a way to improve the community, the national economy, and the environment.