Controlling the Interaction Between Carbon Dioxide and Cementitious Materials Using Biomimetic Molecules

这项研究旨在使可持续的基础设施材料，包括辅助胶凝材料（SCM）和碱活性材料（AAM），通过减少它们暴露于二氧化碳时的劣化，使其使用寿命更长。这项研究将通过促进对可直接作为二氧化碳汇的胶凝材料的理解和应用，进一步为低碳未来做出贡献。这项研究的推广工作涉及与土木工程，材料科学和化学的教师和学生一起开发多学科的劳动力，以应对为民用基础设施创造可持续和耐用材料的挑战。直接的教育好处包括为本科生和高中生以及代表性不足的群体提供指导研究的机会。这些机会将为学生提供接触先进研究设施的机会，并激励他们在基础设施材料领域接受高等教育。本研究将利用仿生工程的生长，聚集，原位沉淀碳酸钙颗粒的特性，以控制胶凝材料和二氧化碳之间的相互作用的方法。具体目标包括：（i）确定原位沉淀亚稳碳酸钙（mCaCO 3）和碳酸钙-有机混合（mCOH）相的有效性，以避免水合硅酸钙（C-S-H）和水合硅酸铝钙（C-A-S-H）凝胶相在暴露于外部二氧化碳时降解，从而增强含有AAM和SCM的水泥基复合材料的抗碳化性;（ii）研究如何使用仿生分子在碳酸化固化基质中沉淀具有受控形态和性质的特定mCaCO 3，以便可以利用其原位形成来开发高性能水泥基质;（iii）研究仿生分子与碳酸钙颗粒的多晶型结晶之间的功能关系，因此，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。

This research aims to make sustainable infrastructure materials, including supplementary cementitious materials (SCMs) and alkali-activated materials (AAM), last longer by reducing their deterioration when these are exposed to carbon dioxide. This research will further contribute to the low-carbon future by advancing the understanding and applications of cementitious materials that can directly serve as carbon dioxide sinks. The outreach effort of this research involves developing a multidisciplinary workforce with faculty members and students from civil engineering, materials science, and chemistry to address the challenges of creating sustainable and durable materials for civil infrastructures. The direct educational benefits include mentored research opportunities for undergraduate and high school students as well as underrepresented groups. These opportunities will provide students with exposure to advanced research facilities and motivate them to pursue higher education in the field of infrastructure materials. This research will capitalize on the biomimetic approaches of engineering the growth, aggregation, and characteristics of in-situ precipitated calcium carbonate particles to control the interaction between cementitious materials and carbon dioxide. The specific objectives include: (i) determining the effectiveness of in-situ precipitated metastable calcium carbonate (mCaCO3) and calcium carbonate-organic hybrid (mCOH) phases to avoid degradation of calcium silicate hydrate (C-S-H) and calcium aluminum silicate hydrate (C-A-S-H) gel phases when exposed to external carbon dioxide, thus enhancing the carbonation resistance of cementitious composites containing AAMs and SCMs; (ii) investigating how biomimetic molecules can be used to precipitate specific mCaCO3 with controlled morphologies and properties in carbonation cured matrices so that their in-situ formations can be leveraged to develop high-performance cementitious matrices; (iii) investigating the functional relationship between biomimetic molecules and the polymorphic crystallization of calcium carbonate particles, and therefore, developing non-natural and affordable biomimetic molecules that can be used as chemical admixtures in cementitious materials.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.