Using Nanoparticles to Confine Molecular Self-Assembly

使用纳米粒子限制分子自组装

• 批准号: 0755654
• 负责人: Guangzhao Mao
• 金额: $ 29.85万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2013-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0755654&HistoricalAwards=false
• 关键词: Using; Nanoparticles; Confine; Molecular; Self

CBET-0755654MaoThe project is at the interface of two active research areas: nanoparticle arrays and organic thin films. Self assembled monolayers of amphiphiles are relevant to biological processes and in lubrication, colloidal stabilization, and detergency. Nanoparticle arrays are applicable to thin film devices. The overall objective of this proposal is to explore the possibility of nucleating molecular nanorods on inorganic nanoparticle surfaces in order to explore the nanoconfinement effect in templated crystallization and to generate a unique hybrid nano architecture. Experimental and theoretical evidence in non epitaxial seed mediated nucleation suggests that a critical seed size and the presence of other confinement effects are necessary for the selective formation of rod like nanoclusters attached to the nanoparticle seeds. To test this hypothesis, gold nanoparticles of various sizes will be used and physicochemical experiments will be conducted to characterize and understand the underlying molecular self assembly mechanisms of the hybrid architectures. The proposed study will continue a preliminary investigation of co-deposited cadmium selenide nanoparticles with eicosanoic acid, by using gold nanoparticles of varying sizes immobilized on solid substrates as models. Additionally, our ability to regulate the overall geometry of the hybrid by controlling seed shape, and our ability to impart electrical conductivity to the organic component, will be explored. The kinetics of crystallization will be probed by in situ AFM experiments. In addition to ongoing collaboration with Dr. Helmuth Mohwald at the Max Planck Institute of Colloids and Interfaces, the proposal will seek to characterize the hybrid ultrathin film structure by neutron diffraction/scattering through collaboration with Dr. Stuart M. Clarke at the University of Cambridge. Intellectual Merit. Shape restrictive nucleation stems from the high curvature of a nanoparticle surface, which imposes unsustainable strains for tangential crystal growth. Other alternative controls for nanoparticle mediated nucleation of nanorods will be explored, which may include high supersaturation, favorable wetting of seed by nucleus, 1D growth habit, and seed surface defects. The seed mediated nucleation represents an alternative approach to nanoparticle and nanorod integration. Unlike previous work using seeds of the same building blocks as the nuclei, the proposed work will investigate the formation of the nanoparticle/nanorod architecture using heterogeneous and non epitaxial seed mediated nucleation, i.e. the nucleus is made of different building blocks (organic) than those of the seed (inorganic). The confinement control for small molecules at molecular length scales, 0.11 nm, is more difficult than the confinement by polymer length scales, 10100 nm. To date, very few reliable measurements of microscopic mechanisms and kinetics of molecular crystal formation at early stages have been made. If successful, the solutionbased, room temperature approach will facilitate divergent combinatorial and scalable chemistry for the construction of branched nano objects. The hybrid nanostructure allows the size dependent properties of each component to be tuned independently. Broader Impacts. Crystallization confined to nano media impacts a number of emerging technologies including thin film and high throughput screening devices. From a human resources perspective, U.S. students will gain international research experience by working with world leading institutions in interfacial materials research. Underrepresented undergraduate students will be recruited from the Michigan Louis Stokes Alliance for Minority Participation Program to participate in this global research training.

CBET-0755654MAOTHE项目位于两个主动研究领域的界面：纳米颗粒阵列和有机薄膜。两亲物的自组装单层与生物过程以及润滑，胶体稳定和洗涤性有关。纳米颗粒阵列适用于薄膜设备。该提案的总体目的是探索在无机纳米颗粒表面上分子纳米棒成核的可能性，以探索模板结晶中的纳米结构效应并产生独特的杂化纳米结构。非外在种子介导的成核中的实验和理论证据表明，对于选择性形成杆，如纳米颗粒种子上的纳米簇（如纳米簇）的选择性形成是必要的。为了检验这一假设，将使用各种大小的金纳米颗粒，并将进行理化实验来表征和理解混合体系结构的基本分子自组装机制。拟议的研究将通过使用固定底物作为模型的固定在固体底物上的各种大小的金纳米颗粒，继续对硒化核纳米颗粒进行初步研究。此外，将探索我们通过控制种子形状来调节杂种总体几何形状的能力，并将探索我们对有机成分赋予电导率的能力。结晶的动力学将通过原位AFM实验进行探测。除了在Max Planck胶体和界面研究所与Helmuth Mohwald博士进行持续的合作外，该提案还将寻求通过与剑桥大学的Stuart M. Clarke博士合作，通过中子衍射/散射来表征混合型超薄膜结构。智力优点。形状限制成核源于纳米颗粒表面的高曲率，这对切向晶体生长施加了不可持续的菌株。还将探索用于纳米颗粒介导的纳米棒成核的其他替代控制，其中可能包括高过饱和度，核对种子的有利润湿，一维生长习惯和种子表面缺陷。种子介导的成核代表了纳米颗粒和纳米棒积分的另一种方法。与先前使用与核相同构建块的种子的工作不同，拟议的工作将研究使用异质和非外观种子介导的成核的纳米颗粒/纳米座结构的形成，即，核是由不同的构建块（与种子）组成的（有机体）。在分子长度尺度为0.11 nm处的小分子的限制控制要比聚合物长度尺度（10100 nm）更难。迄今为止，很少有在早期阶段对显微镜机制和分子晶体形成动力学的可靠测量。如果成功，则基于解决方案的室温方法将有助于构造分支纳米物体的分歧组合和可扩展化学。混合纳米结构允许独立调整每个组件的大小相关属性。更广泛的影响。局限于纳米介质的结晶影响会影响许多新兴技术，包括薄膜和高吞吐量筛选设备。从人力资源的角度来看，美国学生将通过与世界领先的界面材料研究中的机构合作获得国际研究经验。将从密歇根州路易斯·斯托克斯联盟（Michigan Louis Stokes Alliance）招募少数族裔参与计划的本科生，以参加这项全球研究培训。