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

化学系的大分子、超分子和纳米化学（MSN）项目支持爱荷华州立大学Javier Vela教授的CAREER奖研究和教育项目。Vela教授和他的学生研究了新的表面配体掺杂策略，能够控制每个纳米晶体的功能化程度或价。作为这项工作的一部分，Vela教授的团队将研究由表面修饰引起的配体组织、表面化学和纳米晶体性质的变化。控制每个纳米晶体的功能化程度仍然是胶体半导体领域尚未解决的挑战。表面改性通常通过与过量羧酸或氨基端硫醇交换配体来进行。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具有化学活性的天然配体的表面掺杂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，并探索利用表面掺杂量子点进行镧系光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，为跨越无机-有机-溶剂界面的激子衰变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纳米晶体的表面亲和力和渗透性，以及其在生物组织和亚细胞结构中定位、穿透和运输的能力。此外，表面掺杂纳米晶体的高级表征将进一步加深我们对表面配体组织及其如何影响光电性能的理解。该提案的教育目标是通过在爱荷华州立大学引入一个大学范围的纳米系列研讨会和纳米化学课程来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学生和家庭提供多样化的招聘和双语活动来扩大参与。每周一次的研讨会和一门正式课程将促进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教授将直接面向日益增长的人口，以提高对纳米科学的认识和倡导，将其作为改善社区、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.