Statistical Mechanics of Soft Matter

科罗拉多州立大学的Grzegorz Szamel得到了化学系化学理论、模型和计算方法项目的一个奖项的支持，以研究活性物质。活性物质系统由从其环境中吸收能量并使用它来执行定向运动的物体组成。例子包括细菌和Janus胶体颗粒，具有不同性质的两个不同侧面的颗粒。两面神粒子能够移动是由于在其中一面催化的化学反应。 因为活性物质系统不断地消耗和耗散能量，它们永远不会处于平衡状态。 它们是在内部驱动的，在单个组件的级别上。活性物质系统表现出迷人的宏观结构和动力学，例如自发自组装或图案形成。 对活性和宏观行为之间关系的基本理解可能会导致实际应用，例如新材料的设计和组装。Grzegorz Szamel和他的团队开发了新的方法来研究活跃的物质系统如何流动以及波动在这些系统中的作用。 这项研究的动机来自于缺乏一个通用的理论框架来描述活性物质，在这一领域的实验结果越来越复杂和活性物质系统在化学，生物和材料科学设置的实际重要性的结合。Szamel和他的研究小组推导并测试了研究非热活性流体粘弹性的新方法。基于最近在非平衡小热系统方面的进展，他们正在发展小活性物质系统的随机热力学。 最后，他们正在研究活性玻璃态流体的非平衡特性。 他们正在研究这些系统中的有效温度、微观电流和熵产生率。这项研究的长期目标是发展对活性物质性质的基本理解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Grzegorz Szamel of Colorado State University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry division to study active matter. Active matter systems consist of objects that take in energy from their environment and use it to execute directed motion. Examples include bacteria and Janus colloidal particles, particles with two distinct sides with different properties. Janus particles can move due to a chemical reaction that is catalyzed on one of these sides. Because active matter systems are constantly consuming and dissipating energy, they are never in equilibrium. They are driven internally, at the level of individual components. Active matter systems exhibit fascinating macroscopic structure and dynamics, for example spontaneous self-assembly or pattern formation. The fundamental understanding of the relation between the activity and the macroscopic behavior may lead to practical applications, e.g. the design and assembly of new materials. Grzegorz Szamel and his group develop new methods to study how active matter systems flow and the role of fluctuations in these systems. The motivation for this research comes from the combination of the absence of a general theoretical framework to describe active matter, the increasing sophistication of experimental results in this area and the practical importance of active matter systems in chemical, biological and materials science settings. Szamel and his research group derive and test new methods to study the viscoelastic properties of athermal active fluids. Building on recent advances in out-of-equilibrium small thermal systems, they are developing stochastic thermodynamics of small active matter systems. Finally, they are studying the non-equilibrium features of active glassy fluids. They are investigating effective temperatures, microscopic currents and entropy production rates in these systems. The long-term goal of this research is to develop a fundamental understanding of the properties of active matter.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.