Active Self-assembly Driven by Chemistry: Enhanced Kinetics, Reduced Errors, Novel Patterns and Adaptive Nanostructures

化学驱动的主动自组装：增强动力学、减少错误、新颖模式和自适应纳米结构

• 批准号: 0933583
• 负责人: Yunfeng Shi
• 金额: $ 23.23万
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-15 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0933583&HistoricalAwards=false
• 关键词: Active; Self; assembly; Driven; Chemistry

0933583ShiIntellectual Merit: This project seeks to understand active self-assembly of chemically driven nanoscale building blocks using multi scale simulations. Motivated by natural systems, self assembly technique offers spontaneous, massively parallel structure formation from bottom-up. So far, most research efforts have been focused on static self assembly that is thermally driven towards a thermodynamic equilibrium. Significant challenges remain on how to control the kinetics, assembly defects and to broaden the types of structures that can be self-assembled. Less attention has been paid to dynamic self assembly that evolves to a non equilibrium steady state under a dissipative driving force. Indeed, dynamic self assembly is the dominant assembly mode in biological systems that ought to be learned. A few investigations on dynamic self-assembly utilized either macroscopic building blocks under non chemical forces, or biological building blocks propelled by biomolecular motors. However, the self assembly of nanoscale building blocks driven by chemical reactions, which is more relevant to today's nanofabrication techniques, is largely unexplored. Using state of the art simulation techniques, active self assembly of nanoscale building blocks will be investigated. The dissipating chemical energy will be introduced by means of exothermic catalytic reactions. These reactions can influence the assembly process by: (1) providing a mechanical driving force via a chemomechanical coupling; (2) inducing a conformational change of the building blocks; (3) altering the chemical composition, temperature and flow of the environment. Therefore, the dissipative chemical force can influence the momentum, interaction and shape of the building blocks as well as the fluid environment. As a consequence, active self assembly should possess attractive properties including enhanced kinetics, reduced assembly errors, adaptability and novel assembly patterns. Through this proposed effort, molecular-level understanding of the complex behavior of active self assembly will be developed, the benefits of active self assembly will be demonstrated and the design rules for experimental realization will be distilled.Broader Impacts: The broader scientific impacts are two fold. First, the dynamic self assembly considered here, i.e., the assembly process of nanoscale building blocks driven by catalytic chemical reactions, provides an attractive, fully tunable system to investigate the non equilibrium pattern formation. The insights revealed here will have broad implications in physics, biology and social science. Second, the suite of simulation techniques to be developed is unique that is capable of modeling hydrodynamics, diffusion, catalytic chemical reactions and conformational changes concurrently. Thus it can be used to study diffusion reaction coupling, energy conversion processes and other bio-mimetic systems at the molecular level.The PI is devoted to building a long term out reach partnership with the Troy High School. The planned activities include delivering lectures to the high school students and organizing science tours to Rensselaer, in an effort to attract underrepresented students into science and engineering. The research tools developed in this effort, including the simulation, visualization and analysis software, will be freely available to researchers worldwide.

0933583 Shi智力优点：该项目旨在了解使用多尺度模拟的化学驱动纳米级构建块的主动自组装。受自然系统的启发，自组装技术提供了自下而上的自发，大规模并行结构形成。到目前为止，大多数研究工作都集中在静态自组装上，这种自组装是由热驱动达到热力学平衡的。在如何控制动力学、组装缺陷和拓宽可自组装结构的类型方面仍然存在重大挑战。动力学自组装是在耗散驱动力作用下演化到非平衡稳态的过程，但这方面的研究较少。事实上，动态自组装是生物系统中应该学习的主要组装模式。动态自组装的一些研究利用非化学力下的宏观构建块，或生物分子马达推动的生物构建块。然而，由化学反应驱动的纳米级构建块的自组装，这与今天的纳米纤维技术更相关，在很大程度上尚未探索。使用最先进的模拟技术，积极的自组装纳米级积木将进行调查。耗散的化学能将通过放热催化反应引入。这些反应可以通过以下方式影响组装过程：（1）通过化学机械偶联提供机械驱动力;（2）诱导结构单元的构象变化;（3）改变环境的化学组成、温度和流动。因此，耗散化学力可以影响构件的动量、相互作用和形状以及流体环境。因此，主动自组装应该具有吸引人的特性，包括增强的动力学、减少的组装错误、适应性和新颖的组装模式。通过这一拟议的努力，分子水平的理解的复杂行为的主动自组装将被开发，主动自组装的好处将被证明和设计规则的实验实现将被蒸馏。首先，这里考虑的动态自组装，即，由催化化学反应驱动的纳米级结构单元的组装过程提供了一种有吸引力的、完全可调的系统来研究非平衡图案的形成。这里揭示的见解将在物理学，生物学和社会科学中产生广泛的影响。其次，要开发的模拟技术套件是独一无二的，能够同时模拟流体力学、扩散、催化化学反应和构象变化。因此，它可以用来研究扩散反应耦合，能量转换过程和其他仿生系统在分子水平上。PI致力于建立一个长期的外展与特洛伊高中的合作伙伴关系。计划开展的活动包括为高中生举办讲座和组织伦斯勒科学图尔斯之旅，以吸引代表性不足的学生进入科学和工程领域。在这项工作中开发的研究工具，包括模拟、可视化和分析软件，将免费提供给世界各地的研究人员。