CAREER: Toward Geomimetic Concretes

受地壳中奇异化学反应的启发，该奖项侧重于对流固界面化学反应的基本理解，并利用这一基本见解来设计负碳几何混凝土材料。普通波特兰水泥基混凝土的生产约占全球人为碳排放量的7%，占全球工业淡水提取量的9%。这就需要基础设施材料的发展，这些材料不仅具有碳汇，而且具有水意识。设计这种可持续材料技术的进展原则上受到二氧化碳-水-固体界面发生的化学反应的复杂性的困扰。在理解这种非均相化学反应机理方面的突破不仅有利于环保建筑材料的设计，而且在调节土壤承载反应、确定地球系统中污染物的命运和理解环境催化方面也具有许多意义。这个教师早期职业发展（Career）奖还将激发协同教育努力，在K-12和本科生中，特别是在美国英语学习者中占很大一部分的双语西班牙语早期学习者中，突出可持续建筑材料的重要性。当涉及到描述湿化富二氧化碳流体的碳化过程时，长期存在的通过溶解-沉淀过程的大量水流体介导的碳化过程范式变得完全无关紧要。这种模式的变化在地质环境中得到了特别的证明，有报告称，在缺水流体中碳矿化加速。碳化动力学的增强与界面水膜的形成密切相关，界面水膜具有独特的反应物/溶剂化学物理性质，并有效地作为纳米限制浴，介导化学反应。尽管开发碳化混凝土具有巨大的技术意义，但水纳米膜中反应性增强的界面过程的机理以及相关的热力学和动力学仍然难以捉摸。通过整合分子模拟和原位和非原位光谱技术，本研究提供了在纳米受限介质中控制碳矿化的纳米受限过程的分子水平理解。这些过程包括纳米多孔介质中的多相流体偏析、纳米约束结晶过程以及吸附水层和阳离子浸出玻璃态硅酸盐中的弥漫性质量传递。该奖项反映了美国国家科学基金会的法定使命，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。

Inspired by the exotic chemical reactions in earth’s crust, this award focuses on the fundamental understanding of the chemical reactions at the fluid-solid interfaces and leverages this basic insight to design carbon-negative geomimetic concrete materials. The production of ordinary Portland cement-based concretes is responsible for about 7 percent of global anthropogenic carbon emissions and about 9 percent of industrial freshwater withdrawals worldwide. This necessitates the development of infrastructure materials that are not only carbon sink but also water conscious. The progress in designing such sustainable material technologies is in principle confounded by the complexity of chemical reactions occurring at the carbon dioxide-water-solid interfaces. The breakthrough in understanding the mechanistic picture of such heterogenous chemical reactions will not only benefit the design of eco-friendly construction materials, but also entails numerous implications in tuning soil-hosted reactions, determining the fate of contaminants in the geosystems, and understanding environmental catalysis. This Faculty Early Career Development (CAREER) award will also instigate synergistic educational efforts to engrave the significance of sustainable construction materials in K-12 and undergraduate students, especially bilingual Hispanic early-learners, who make up a significant portion of the US English language learner population. When it comes to describing the carbonation process with humidified CO2-rich fluids, the long-standing paradigms for bulk aqueous fluid-mediated carbonation via the dissolution-precipitation process become simply irrelevant. Such a change in paradigm is particularly evidenced in geological settings with reports of accelerated carbon mineralization in water-poor fluids. The enhanced carbonation kinetics is hypothesized to be closely related to the formation of interfacial water films that exhibit unique reactant/solvent chemophysical properties and serve effectively as a nano-confining bath mediating chemical reactions. Despite the vast technological implications in developing carbonated concretes, the mechanistic picture of the interfacial processes accountable for the enhanced reactivity in water nanofilms and the associated thermodynamics and kinetics remain elusive. By integrating molecular simulations and in situ and ex situ spectroscopy techniques, this research provides a molecular-level understanding of the nanoconfined processes that govern carbon mineralization in nanoconfined media. These processes include multi-phase fluid segregation in nanoporous media, nanoconfined crystallization processes, and diffusive mass transport in the adsorbed water layers and cation-leached glassy silicates.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.