NIRT: Multiscale Simulation of the Synthesis, Assembly and Properties of Nanostructured Organic/Inorganic Hybrid Material

该提案是应“纳米科学与工程”（NSF-00-119）的要求提交的。 由此产生的赠款是由材料研究和化学和热系统的部门共同资助。 这项研究将在田纳西大学、密歇根大学和弗吉尼亚大学进行。 参与其中的还有美国国家标准与技术研究院（NIST）、混合塑料（Hybrid Plastics）和塔尔材料（Tal Materials）。多面体油聚倍半硅氧烷（POSS）分子是独特的纳米结构。 POSS分子具有多面体核，其可以是多官能的并且充当可以被合成改性以含有用于聚合、粘附、光敏化、结合催化剂物质和改善的溶解度的基团的平台。 用不同的有机或无机基团独立地官能化POSS立方体的每个角的能力赋予了由POSS分子组装体制成的几乎无限阵列的可能的混合纳米结构。 根据POSS笼的官能化，所得系统可以是固体或液体，或者在交联后变成网络。 它们是一个真正的纳米结构的建筑块，通过自我和引导组装，可以转化为一个显着的产品阵列，并由于最近在快速合成技术的突破，只是现在才成为可用于工业上的商业规模。虽然很多是已知的实验关于POSS系统的化学合成，很少有理论上的理解存在于分子水平或超越。 特别是，单个POSS分子可以在纳米级组装和操纵以形成中尺度和宏观尺度系统的方式尚未研究。 在这项资助中，将开发一个多尺度计算框架来模拟POSS系统的合成和自组装和引导组装。为了在多个层次上解决POSS系统，从量子力学开始到介观和宏观，主要研究人员（PI）具有从电子结构计算到分子模拟的必要专业知识。 这些专业知识将应用于三个初始问题：（1）交联POSS网络的结构;（2）纳米结构相预测;（3）模板纳米结构薄膜。 可行的多尺度建模路线来描述这些系统已经开发，基于专业知识和代码之间的PI的。 随着建模工作的发展，将进行修改。 开发的模拟代码将在公共领域，记录在用户手册和技术报告中，并分发给用户社区。 这些技术将能够基本上从第一原理预测混合无机/有机纳米结构系统的物理和结构特性。%%%***

This proposal was submitted in response to the solicitation "Nanoscale Science and Engineering" (NSF-00-119). The resulting grant is co-funded by the Divisions of Materials Research and Chemical and Thermal Systems. The proposed research will be carried out at the Universities of Tennessee, Michigan and Virginia. Also participating are NIST, Hybrid Plastics and Tal Materials.Polyhedral oilgomeric silsesquioxane (POSS) molecules are unique nanometer-sized structures. POSS molecules have a polyhedral core which can be multifunctional and serve as platforms that can be synthetically modified to contain groups for polymerization, adhesion, light sensitization, binding catalyst species, and improved solubility. The ability to independently functionalize each corner of a POSS cube with different organic or inorganic groups confers a nearly infinite array of possible hybrid nanostructures made of assemblies of POSS molecules. Depending on the functionalization of the POSS cages, the resulting systems can be solid or liquid, or on crosslinking turned into a network. They are a truly nanostructured building block, which, through self-and guided-assembly, can be transformed into a remarkable array of products, and due to recent breakthroughs in rapid synthesis technology, are only just now becoming available to industry on a commercial scale.While much is known experimentally about the chemical synthesis of POSS systems, very little theoretical understanding exists at the molecular level or beyond. In particular, the way in which individual POSS molecules can be assembled and manipulated at the nanoscale to form meso-and macro-scale systems has not been studied. In this grant a multiscale computational framework will be developed to simulate the synthesis and self-and guided-assembly of POSS systems.In order to address POSS systems at many levels, beginning at the quantum mechanical through to the mesoscale and macroscopic, the principal investigators (PI's) have the requisite expertise ranging from electronic structure calculations to molecular simulation. This expertise will be applied to three initial problems: (1) structure of cross-linked POSS networks; (2) nanostructured phase prediction; and, (3) templated nanostructured thin films. Feasible multiscale modeling routes to describing these systems have been developed, based on the expertise and codes available among the PI's. Modifications will be made as the modeling effort evolves. The simulation codes developed will be in the public domain, documented in user manuals and technical reports, and distributed to the user community. These techniques will enable the prediction, essentially from first principles, of the physical and structural properties of hybrid inorganic/organic nanostructured systems. %%%***