Theory for dynamic matter: designing mechanisms for dissipative nanomaterials

马萨诸塞大学波士顿分校的Jason R.Green教授得到了化学系化学理论、模型和计算方法计划的支持，以促进我们对化学如何控制活性材料的形式和功能的基本理解。活性材料是设计成具有一种或多种性质的材料，这些性质可以通过外部刺激(如温度、光或化学反应)以可控的方式显著改变。在实验室里，化学反应被用来组装、维持、调节和破坏由活性、响应性分子组成的材料的结构。通过操纵化学反应，人们可以调整它们的性质。这类材料有许多潜在的应用，例如在药物输送和生物传感方面。然而，这些材料的性能取决于结构形成的历史和细节。因此，从组成分子构建块的性质来预测屈服和力学行为是一个挑战。格林教授和他的同事们正在开发理论框架来克服这一挑战。他们的目标是提供对物质动态能力的洞察，以便在化学能量提供燃料时找到通往稳定、功能结构的替代途径。格林教授还在创造开放科学的计算笔记本，其中包含可访问的、计算上容易处理的、与实验相关的自组装模型。自组装作为一种合成复杂材料的简单技术具有实用前景。分子组分组成活性物质，当它们耗散能量时，只能暂时维持结构。主要的挑战是理解材料性质的时间依赖性和变化的反应条件的影响。该项目正在开发适当的理论框架，以了解非平衡力如何集体驱动结构形成和塑造广阔的组装路径空间。我们的目标是从精确模拟实验的随机化学动力学中预测哪些途径是典型的，哪些是宏观尺度上罕见的。这项研究做出了三项主要贡献：在活性物质非平衡组装的建模和模拟方面取得进展，在确定组装模式和结构形成的原因机制方面取得理论和实践上的进步，并为平衡状态下和从平衡态演化而来的自组装模型数据库收集随机热力学。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Professor Jason R. Green of the University of Massachusetts Boston is supported by an award from the Chemical Theory, Models and Computational Methods Program in the Chemistry Division to advance our fundamental understanding of how chemistry controls the form and the function of active materials. Active materials are materials designed to have one or more properties that can be significantly changed in a controlled fashion by external stimuli such as temperature, light, or chemical reactions. In the laboratory, chemical reactions are used to assemble, sustain, regulate, and destroy the structure of materials made from active, responsive molecules. By manipulating the chemical reactions, one can tune their properties. Such materials have many potential applications, for example in drug delivery and biosensing. However, the properties of these materials depend on the history and the details of how the structure was formed. As a result, it is a challenge to predict the yield and mechanical behavior from the properties of the constituent molecular building blocks. Professor Green and coworkers are developing theoretical frameworks to overcome this challenge. Their goal is to provide insight into the dynamic ability of matter to find alternative routes to stable, functional structures when fueled by chemical energy. Professor Green is also creating open-science computational notebooks that contain accessible, computationally tractable, and experimentally-relevant models for self-assembly.Self-assembly has practical promise as a simple technique to synthesize complex materials. Molecular components organize into active materials that can only sustain structure transiently as they dissipate energy. The principal challenges are understanding the time dependence of material properties and the effect of changing reaction conditions. This project is developing appropriate theoretical frameworks for understanding how non-equilibrium forces collectively drive structure formation and sculpt the vast space of assembly pathways. The goal is to predict which pathways are typical and which are rare at the macroscopic scale from stochastic chemical-kinetics that accurately model experiments. This research is making three major contributions: advancing in the modeling and simulation of the nonequilibrium assembly of active materials, advancing in the theory and practice for identifying the assembly patterns and causal mechanisms of structure formation, and collecting the stochastic-thermodynamics for a database of self-assembly models at and evolving away from equilibrium.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.