The physical chemistry of macromolecular conformation and directed aggregation: towards control of nanoparticle aggregates and composites

大分子(如聚合物、蛋白质和核酸)可以有多种构象。当处于凝聚相时，无论是纯的还是混合的，材料的性质不仅取决于组成，而且还取决于构象和分子间的组织。从应用的角度来看，这提供了另一种方法--材料性质可以不通过打破和形成化学键来改变，而是通过依赖于材料加工的简单物理方法来改变。这种方法主要是在聚合物行业进行的，但在其他地方还没有得到充分的分析或开发。这个项目的目标是深入了解大分子的相互作用，控制它们的构象，它们相互聚集和形成复合材料的能力。我们将研究三种不同类型的纳米粒子系统的形成：生物分子；聚合物，特别是聚电解质；以及聚合物-无机纳米粒子杂化。然后，这些纳米颗粒将被制造成更高阶的聚集体和纳米复合材料，以达到理想的性能和功能。在每个阶段，这项工作将涉及：(1)开发制造和处理初始材料的方法；(2)主要使用显微镜和光谱学进行表征；(3)性能测量；(4)初始计算和建模；以及(5)具有目标性能的材料的设计和实施。

Large molecules (e.g, polymers, proteins and nucleic acids) can have a variety of conformations. When in the condensed phase, whether pure or in mixtures, the material properties depend not just on composition but also on conformation and intermolecular organization. From the point of view of applications, this presents an alternative approach - that material properties can be altered not by breaking and making chemical bonds, but by a simple physical approach that relies on materials processing. Such approach is pursued mainly empirically in the polymer industry but has not been fully analyzed or exploited elsewhere. The goal of this program is to get insight on the interactions of large molecules, to control their conformation, their ability to aggregate with each other and to form composite materials. We will look at the formation of nanoparticle systems of three different types: biomolecules; polymers, particularly polyelectrolytes; and polymer-inorganic nanoparticle hybrids. These nanoparticles will then be made to form higher order aggregates and nanocomposites, targetting desirable properties and functionalities. At each stage, the work will involve: (1) developing an approach for making and handling the initial material, (2) characterization, primarily with microscopy and spectroscopy; (3) measurement of properties; (4) initial computation and modeling; and (5) design and implementation of material with targeted properties.