CAREER: Realizing Alternative Cements with Chemical Kinetics: Tuned Mechanical–Chemical Properties of Cementitious Magnesium Silicate Hydrates by Multi-Scale Synthetic Control

职业：利用化学动力学实现替代水泥：通过多尺度合成控制调整胶凝硅酸镁水合物的机械和化学性能

• 批准号: 2342381
• 负责人: Erika La Plante
• 金额: $ 57.66万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2342381&HistoricalAwards=false
• 关键词: CAREER; Realizing; Alternative; Cements; Chemical

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).The high energy needs and environmental burden of the construction industry have driven efforts to discover new cementitious materials. Cements based on the bonding between magnesium and silicon, such as magnesium silicate hydrates (MSH), are among the less explored alternatives. The characteristics that control their cementitious nature, i.e., the rates of precipitation, structural mechanisms for strengthening, and stability in relevant environments, are not known and this hinders their widespread use. This Faculty Early Career Development (CAREER) project will reveal new pathways for the chemical synthesis of cementitious MSH and the chemical control of their consequent morphological, mechanical, and chemical properties. Meaningful undergraduate research experiences targeting women and underrepresented minority students at the home and neighboring institutions including a community college will improve STEM and transfer student outcomes, enrich graduate student training, and create a pipeline of students interested in materials science and engineering, cultivating the nation’s future workforce. To enhance the experience, the students will create educational videos that showcase the “Materials Science of Cements and Concrete” that will be distributed to small construction businesses in Dallas–Fort Worth to improve job appreciation and skill in the construction workforce that supports the area’s rapidly growing population through infrastructure development. This research will emphasize an integrated approach involving dynamic high-resolution methods to probe, drive, and manipulate MSH synthesis, structures, and properties from nucleation to bulk growth with a focus on the phenomena that occur at the MSH–fluid interface. This will be accomplished through the following steps. First, precipitation rates, morphologies, and compositions that quantitatively describe MSH growth kinetics will be investigated using a combination of in situ and ex situ surface-sensitive analytical methods and interpreted using mechanistic models applied to sheet silicates. Second, MSH mesocrystalline organization will be understood within the electric double layer theoretical framework and manipulated using polyelectrolytes and electrochemical forcing. Third, local mechanical and surface properties will be quantified and related to macroscale mechanical properties of MSH binders, and the rates and mechanisms of MSH degradation will be investigated. Key analytical methods used include atomic force microscopy, kinetic geochemical modeling, infrared spectroscopy, electron microscopy, electrochemical methods, and synchrotron X-ray scattering. This research will ultimately reveal processing–structure–property relationships in MSH cements, establishing their viability as a binder material for construction purposes and an alternative to ordinary Portland cement. The fundamental science and discovery gained will expand our understanding of low-temperature mineral crystallization processes and the subsequent property development across spatial and temporal scales.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.

该奖项是根据2021年《美国救援计划法》（公法117-2）全部或部分资助的。建筑行业的高能源需求和环境燃烧促使人们努力发现新的水泥材料。基于镁和硅之间的粘合物（例如硅水合物（MSH））是探索较少的替代品之一。尚不清楚控制其固定性的特征，即降水速率，加强结构机制和稳定性的特征，这是尚不清楚的，这阻碍了它们的广泛使用。这个教师的早期职业发展（职业）项目将揭示胶状炎的化学合成MSH的新途径，以及其随之而来的形态学，机械和化学特性的化学控制。有意义的本科生研究经验针对家庭和包括社区学院在内的邻近机构的女性和代表性不足的少数族裔学生将改善STEM和转移学生成果，丰富研究生培训，并建立对材料科学和工程学感兴趣的学生，从而培养国家的未来劳动力。为了增强体验，学生将创建展示“水泥和混凝土材料科学”的教育视频，这些视频将分发给达拉斯 - 福特的小型建筑企业，以提高建筑劳动力的工作欣赏和技能，以支持该地区通过基础设施开发来快速增长的人口。这项研究将强调一种涉及动态高分辨率方法的综合方法，以探测，驱动和操纵MSH合成，结构和特性，从成核到批量生长，重点是在MSH – Fluid界面处发生的现象。这将通过以下步骤完成。首先，将使用原位和异位表面敏感的分析方法的组合研究定量描述MSH生长动力学的降水速率，形态和组成，并使用应用于薄板硅酮的机械模型来解释。其次，将在电动双层理论框架内理解MSH中晶组织，并使用聚电解质和电化学强迫进行操纵。第三，将量化局部机械和表面特性，并与MSH粘合剂的宏观机械性能有关，并将研究MSH降解的速率和机制。所使用的关键分析方法包括原子力显微镜，动力学模型，红外光谱，电子显微镜，电化学方法和同步加速器X射线散射。这项研究最终将揭示MSH水泥中的加工 - 结构 - 专业关系，确立它们作为构造目的的粘合剂材料的生存力，并成为普通波特兰水泥的替代品。获得的基本科学和发现将扩大我们对低温矿物结晶过程以及随后在空间和临时规模的物业发展的理解。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和广泛影响的评估来评估的珍贵支持。

项目成果

Chemical structure and complex growth modes of magnesium silicate hydrate: Nanoparticle orientation, aggregation, and fusion

• DOI: 10.1016/j.cemconres.2023.107367
• 发表时间: 2024-01
• 期刊: Cement and Concrete Research
• 影响因子: 11.4
• 作者: Dylan Singh;Trinh Thao My Nguyen;Evann Bustamantes;Abdul Wahab;Ahmad Hamzah Yousaf;Ian Shortt;Frank W. Foss;Maria Konsta-Gdoutos;Sang Soo Lee;Erika Callagon La Plante