Nanoparticle-directed synthesis of organic nanorods

有机纳米棒的纳米颗粒定向合成

• 批准号: 1404285
• 负责人: Guangzhao Mao
• 金额: $ 32.93万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1404285&HistoricalAwards=false
• 关键词: Nanoparticle; directed; synthesis; organic; nanorods; Nanoparticle; directed; synthesis; organic; nanorods

Guangzhao Mao from Wayne State University is supported by an award from the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry to investigate organic nanorod growth on an inorganic nanoparticle, the "seed" which is several nanometers (billionths of a meter) across. The long-range goal is to learn to build tiny devices that combine the functions of organic and inorganic nanomaterials. The specific objectives are: 1) to investigate growth of these organic structures using gold nanoparticles seeds, 2) to show what effects on the nanorods depend on the seed size and shape, and 3) to make conductive organic nanorods by crystallizing charged organic molecules using electric current at the nanoparticles. The research contributes knowledge of nucleation and crystallization at the nanoscale, which is critical in nanomaterials synthesis and applications. The proposed real-time measurements are challenging because of the time and length scales of nucleation and growth processes and their inherent transient nature. To date, very few reliable measurements of the microscopic mechanisms and kinetics of molecular nucleation have been made. The synthesis of nanorods and nanowires from small organic molecule electrochemistry is transformative because most nanorods synthesized before have been of inorganic materials. The seed-mediated process is applicable to the manufacturing of inexpensive and field-ready electrochemical sensors. The educational plan focuses on three areas: 1) integration of research and teaching infrastructure by utilizing NSF MRI resources, 2) mentoring underrepresented students by working with the Wayne State University GO-GIRLS program, and 3) providing research experiences for undergraduates.Nanoparticles as nucleation seeds inhibit nucleation below a critical seed size and promote nucleation of crystals with different morphology than bulk in a size range above the critical size. The primary hypothesis is that the small size of nanoparticles imposes an unsustainable strain in the nucleated crystal and leads to the nanorod shape. An alternative hypothesis is the crystallographic confinement imposed by crystalline facets, edges, or corners of the nanoparticle seed. Two different systems, carboxylic acid crystals in evaporative crystallization and tetrathiafulvalene charge-transfer salt crystals in electrocrystallization allow a rigorous test of the primary and alternative hypotheses. Electrocrystallization affords a precise control of the nucleation and crystallization process, which is critical for understanding the seed-mediated process. Unlike work by others using seeds of similar building blocks as the nuclei, the work investigates the formation of the nanoparticle/nanorod architecture using heterogeneous and non-epitaxial seed-mediated nucleation. The hypotheses are examined by real-time electrochemical AFM experiments of the charge-transfer salt crystallization on gold nanoparticle-decorated electrodes. The proposed study explores an alternative strategy to integrate molecular and supramolecular components into nanodevices. In order for organic species to be used in nanodevices, the effect of area or shape confinement on molecular self-assembly must be addressed. The proposed research is significant because 1) the method incorporates organic species to make truly hybrid nanostructures; 2) the modular approach facilitates divergent combinatorial electrochemistry; and 3) the solution-based room-temperature process is potentially scalable for the manufacturing of molecular conductors, connectors, switches, and networks.

来自韦恩州立大学的广豪毛毛（Guangzhao Mao）得到了化学部的大分子，超分子和纳米化学计划的奖励，以调查无机纳米粒子上有机纳米棒的增长，即“种子”，这是几种纳米计（亿米三分之一）。远程目标是学习建立结合有机和无机纳米材料功能的微型设备。具体目标是：1）使用金纳米颗粒种子研究这些有机结构的生长，2）显示对纳米棒的影响取决于种子的大小和形状，以及3）通过使用纳米颗粒的电流结晶带电的有机有机分子来制造导电有机纳米棒。该研究有助于纳米级的成核和结晶知识，这在纳米材料的合成和应用中至关重要。提议的实时测量值是具有挑战性的，这是因为成核和生长过程的时间和长度尺度及其固有的瞬态性质。迄今为止，几乎没有对微观机制和分子成核动力学的可靠测量。来自小有机分子电化学的纳米棒和纳米线的合成具有变化性，因为以前合成的大多数纳米棒都是无机材料的。种子介导的工艺适用于制造廉价和现场的电化学传感器。教育计划侧重于三个领域：1）通过使用NSF MRI资源来整合研究和教学基础架构，2）通过与Wayne State University go-girls计划合作来指导代表性不足的学生，以及3）3）提供研究经验，为较小的纳米颗粒提供了较低的型号，而在成核的范围内，纳米颗粒的差异较大，而构成种子的差异，则在成核的范围内促进成核的差异，而成核的成素质，而构成了成核的成构，而不是成核的成构，而不是成核的成构，则是对成核的差异。范围高于临界大小。主要的假设是，纳米颗粒的小尺寸在核晶体中施加了不可持续的应变，并导致纳米体形状。另一种假设是纳米颗粒种子的晶体，边缘或角的晶体学限制。两种不同的系统，蒸发结晶中的羧酸晶体和电晶中的四硫硫酸盐电荷转移 - 转移盐晶体可以对主要和替代假设进行严格的测试。电结构化提供了对成核和结晶过程的精确控制，这对于理解种子介导的过程至关重要。与其他人使用类似于核的种子的种子不同，该作品研究了使用异质和非外观种子介导的成核研究纳米颗粒/纳米棒结构的形成。通过在金纳米粒子装饰的电极上的电荷转移盐结晶的实时电化学AFM实验来研究这些假设。拟议的研究探讨了将分子和超分子成分整合到纳米版本中的替代策略。为了使有机物种用于纳米版本，必须解决面积或形状限制对分子自组装的影响。拟议的研究很重要，因为1）该方法融合了有机物种，以实现真正的混合纳米结构； 2）模块化方法促进了不同的组合电化学； 3）基于溶液的室温工艺可能可扩展用于制造分子导体，连接器，开关和网络。