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.

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。建筑行业的高能源需求和环境负担推动了发现新水泥材料的努力。基于镁和硅之间键合的水泥，如硅酸镁水合物（MSH），是较少探索的替代品。控制其胶凝性质的特性，即，沉淀速率、用于强化的结构机制以及在相关环境中的稳定性都是未知的，这阻碍了它们的广泛应用。这个教师早期职业发展（CAREER）项目将揭示水泥MSH的化学合成及其随后的形态，机械和化学性质的化学控制的新途径。有意义的本科生研究经验，针对妇女和代表性不足的少数民族学生在家里和邻近机构，包括社区学院将提高干和转移学生的成果，丰富研究生培训，并创建学生的管道感兴趣的材料科学和工程，培养国家的未来劳动力。为了增强体验，学生们将制作教育视频，展示“水泥和混凝土材料科学”，这些视频将分发给达拉斯-沃斯堡的小型建筑企业，以提高建筑劳动力的工作价值和技能，通过基础设施发展支持该地区快速增长的人口。这项研究将强调一个综合的方法，涉及动态高分辨率的方法来探测，驱动和操纵MSH合成，结构和性能，从成核到批量生长，重点是在MSH-流体界面发生的现象。这将通过以下步骤实现。首先，沉淀速率，形态和组合物，定量描述MSH生长动力学将使用原位和非原位表面敏感的分析方法的组合进行研究，并使用适用于片硅酸盐的机械模型进行解释。第二，MSH介晶组织将被理解的双电层理论框架内，并使用聚电解质和电化学强迫操纵。第三，局部机械和表面性能将被量化，并与MSH粘合剂的宏观机械性能相关，并将研究MSH降解的速率和机制。使用的主要分析方法包括原子力显微镜、动力学地球化学建模、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。这项研究将最终揭示MSH水泥的加工-结构-性能关系，确定其作为建筑用粘结剂材料和普通波特兰水泥的替代品的可行性。获得的基础科学和发现将扩大我们对低温矿物结晶过程的理解，以及随后在空间和时间尺度上的房地产开发。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。

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