Synthesis of Janus Hybrid Nanoparticles as Colloidal Amphiphiles

作为胶体两亲物的 Janus 混合纳米粒子的合成

• 批准号: 1307192
• 负责人: Jeffrey Pyun
• 金额: $ 35.4万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2016-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1307192&HistoricalAwards=false
• 关键词: Synthesis; Janus; Hybrid; Nanoparticles; Colloidal

TECHNICAL SUMMARY: The synthesis, assembly and polymerization of a new class of hybrid colloids composed of asymmetric nanorods with disparate colloidal components and differentially functionalized polymer ligands will be pursued. These types of hybrid colloids will exhibit Janus-type structural character, as the inorganic colloidal phase will be composed of a single semiconductor nanorod (based on CdSe@CdS) conjugated to a single dipolar cobalt nanoparticle (CoNP). Furthermore, the controllable functionalization of CdSe@CdS nanorod and CoNP surfaces with (co)polymeric ligands will be achieved. This Janus nanoparticle is a novel and unique platform that enables selective and differential functionalization of CoNP and CdSe@CdS nanorod surfaces with different types of polymeric ligands made from controlled radical polymerizations of varying hydrophilicity enabling creation of colloidal amphiphilic nanomaterials. The synthesis and structural variation of colloidal and polymeric components will be the central focus of the research that will enable further studies on the assembly of these Janus NPs and conversion via colloidal polymerization into heterostructured photocatalytic materials. The PI will investigate the self-organization of these amphiphilic Janus NP in solution and at oil-water interfaces to form various colloidal assemblies targeting the formation of linear NP chains with nanorods laterally oriented. Oxidation of the metallic CoNP phases of the Janus NP colloidal assemblies will then be conducted to afford cobalt oxide nanowires carrying CdSe@CdS nanorod side chains along every repeating unit of the cobalt oxide backbone. This methodology affords a route to spatially and electronically ordered p-n semiconductor junctions that are energetically aligned for photocatalysis. The composition, morphology, and electronic structure of these nanomaterials will be investigated via TEM, XRD, photoelectron and optical spectroscopies, along with photocatalysis studies with Janus NP colloidal assemblies and solution optical probe molecules upon irradiation. NON-TECHNICAL SUMMARY:The proposed research aims to develop new methods to prepare novel materials that combine organic polymers and inorganic particles with control of size, shape and function of the different components. This will require the development of new synthetic chemistry to prepare these types of inorganic particles that will be very small in size (i.e., nanoscopic) and decorated with a shell of organic polymer ligands as a plastic coating. Because these types of building blocks are very novel, methods to prepare and hybridize these into a single useful material are lacking, which the proposed research aims to address. Hence, the research is highly interdisciplinary, but grounded in basic and fundamental polymer science. Upon development of these synthetic methods, the preparation of asymmetric nanoparticles will enable evaluation of these materials for energy related problems, such as, photocatalytic generation of hydrogen from water. Furthermore, integration of the research with educational activities with K-12 students will be achieved by joint mentoring projects and a series of lectures given by the PI. Collaborations with South Korean academic institutions (Seoul National University) will also be integrated into this project through joint technical research and educational activities.

技术综述：由具有不同胶体成分的不对称纳米棒和不同官能化的聚合物配体组成的新型杂化胶体的合成、组装和聚合将是一项重要的工作。这些类型的杂化胶体将表现出Janus类型的结构特征，因为无机胶体相将由单个半导体纳米棒(基于CdSe@CDS)与单个偶极钴纳米颗粒(CoNP)结合组成。此外，还将实现具有(Co)聚合物配体的CdSe@CDS纳米棒和CoNP表面的可控官能化。这种Janus纳米粒子是一种新颖而独特的平台，可以使用不同类型的聚合物配体对CoNP和CdSe@CDS纳米棒表面进行选择性和差异化的功能化，这些聚合物配体是由不同亲水性的受控自由基聚合而成的，从而能够创建胶体两亲性纳米材料。胶体和聚合物组分的合成和结构变化将是研究的重点，这将使进一步研究这些Janus纳米粒子的组装和通过胶体聚合转化为异质结构光催化材料成为可能。PI将研究这些两亲性Janus NP在溶液和油水界面上的自组织，以形成各种胶体组装，目标是形成具有横向取向的纳米棒的线性NP链。然后，将对Janus NP胶体组件的金属CoNP相进行氧化，以获得沿着氧化钴骨架的每个重复单元携带CDSe@CDS纳米棒侧链的氧化钴纳米线。这种方法提供了一条在空间和电子上有序的p-n半导体结的路线，这些p-n半导体结在光催化中是能量排列的。这些纳米材料的组成、形貌和电子结构将通过透射电子显微镜、X射线衍射仪、光电子和光学光谱进行研究，同时还将利用Janus NP胶体组装和溶液光学探针分子在光照下进行光催化研究。非技术概述：拟议的研究旨在开发新的方法来制备将有机聚合物和无机颗粒结合在一起的新型材料，并控制不同组分的尺寸、形状和功能。这将需要开发新的合成化学来制备这些类型的无机颗粒，这些颗粒的尺寸将非常小(即纳米级)，并以有机聚合物配体的外壳作为塑料涂层进行装饰。由于这些类型的积木非常新颖，缺乏将其制备并杂交成单一有用材料的方法，而拟议的研究旨在解决这一问题。因此，这项研究是高度跨学科的，但以基础和基础聚合物科学为基础。随着这些合成方法的发展，不对称纳米颗粒的制备将使这些材料能够评估与能源有关的问题，例如从水中光催化制氢。此外，将通过联合辅导项目和由国际学生协会举办的一系列讲座，将研究与K-12学生的教育活动相结合。与韩国学术机构(首尔国立大学)的合作也将通过联合技术研究和教育活动纳入该项目。