Emerging Complexity and Hierarchical Order in Precipitation Reactions

非技术摘要：生命系统以与大多数现有工程策略截然不同的方式生产材料和设备样结构。他们能够通过严格调节工艺条件来生长具有复杂微观到宏观结构的高性能材料（例如骨骼和牙釉质）。此外，生命通过廉价而丰富的起始材料完成了这些壮举。在固态和材料化学项目的支持下，本项目的总体目标是在非生物无机化学领域寻找和开发使用类似策略的例子。如果成功，这项研究将成为一个重要的垫脚石，迈向一个全新的工程范式，在这个范式下，材料是通过外部控制化学自组织和其他复杂性产生机制生产的。这项研究工作与教育和推广活动相结合，包括对本科生和研究生的培训以及通过社会媒体传播研究视频。首席研究员还计划开发一个网站，专门介绍“化学花园”，这是自组织无机反应的最具代表性的例子。该网站旨在为高中教师提供信息，并邀请摄影比赛记录这些化学结构。技术摘要：本项目探索无机沉淀物背景下的模式形成和非平衡过程，旨在促进对宏观管结构和微尺度纳米棒组合（称为生物形态）的理解。其中一些研究受到生命起源假说的启发，该假说认为，在离轴碱性热液喷口的微孔和催化活性沉淀物中发展了益生元化学。具体目标包括从简单的化学和物理参数预测管的形成，以及使用相关材料研究跨膜运输、热泳效应和福尔摩斯反应的特定方面。这种氢氧化钙催化的反应从甲醛中产生包括核糖在内的许多产物，并在RNA世界理论的背景下进行了讨论。第二个研究重点是在二氧化碳涌入下在硅酸盐钡溶液中形成的生物形态。这些10-100微米的大型结构具有类似生命的形态，如心形片和螺旋，由高度有序的碳酸钡纳米棒聚集体组成。为了阐明它们的生长机制和纳米到宏观的结构，研究小组建立了平均场反应-输运模型。建模和仿真工作是基于实验，旨在从流动和电场引起的扰动中识别机械细节。

Non-Technical Abstract:Living systems produce materials and device-like structures in ways that differ profoundly from most existing engineering strategies. They are capable of growing high-performance materials (e.g. bone and tooth enamel) with intricate micro-to-macro architectures by tightly regulating the process conditions. In addition, life accomplishes these feats from inexpensive and abundant starting materials. With the support of the Solid State and Materials Chemistry program, the overarching goal of this project is to find and develop examples that use similar strategies in the realm of non-biological, inorganic chemistry. If successful this research could form an important stepping stone towards an entirely new engineering paradigm under which materials are produced by externally controlling chemical self-organization and other complexity-generating mechanisms. This research effort is integrated with educational and outreach activities that include the training of undergraduate and graduate students and the dissemination of research videos via social media. The principal investigator also plans to develop a website dedicated to "chemical gardens" which are the most iconic example of self-organizing inorganic reactions. The website aims to provide information for high school teachers and invites photo competitions documenting these chemical structures.Technical Abstract:This project explores pattern-forming, nonequilibrium processes in the context of inorganic precipitates with the aim to advance the understanding of macroscopic tube structures and micro-scale nanorod assemblies called biomorphs. Some of these studies are inspired by origins-of-life hypotheses under which prebiotic chemistry developed in the microporous and catalytically active precipitates of off-axis alkaline hydrothermal vents. Specific goals include the prediction of tube formation from simple chemical and physical parameters and the use of related materials for the study of transmembrane transport, thermophoretic effects, and specific aspects of the formose reaction. This calcium-hydroxide-catalyzed reaction generates numerous products including ribose from formaldehyde and has been discussed in the context of RNA world theories. The second research thrust focuses on biomorphs that form in silicate-barium solutions under the influx of carbon dioxide. These 10-100 micrometer large structures have life-like morphologies such as cardioidal sheets and helices and consist of highly ordered aggregates of barium carbonate nanorods. To elucidate their growth mechanism and nano-to-macro architecture, the research team develops mean-field reaction-transport models. The modeling and simulation efforts are based on experiments aiming to identify mechanistic details from flow and electric-field induced perturbations.