CAREER: Understanding Behavior and Properties of Nano-Sized Particles in Cement-Based Materials

这项教师早期职业发展奖将研究纳米颗粒在水泥基材料中的行为和特性。纳米颗粒有可能导致更致密的材料，并继承特定的功能，从而产生新的材料设计可能性，例如智能多功能高度耐用的工程混凝土。这些设计可能性将允许增强性能控制，并将增加有效解决国家老化基础设施目前糟糕状况的潜力，以及为未来的基础设施问题做好准备。目前，由于对纳米颗粒分散在混凝土基质中的机制的有限了解，在水泥基系统中充分释放纳米颗粒的潜力受到阻碍。这些信息对于了解和提高材料的强度和耐久性至关重要。该奖项支持基础研究，为纳米颗粒在水泥基系统中的高质量分散提供所需的知识。通过教育外展活动将产生有意义的影响，a)分享新获得的知识，促进水泥技术的进步，b)激励和激励下一代追求科学、技术、工程和数学(STEM)，让他们发现自己的创造力，以及c)将不同科学学科的知识联系起来，加强土木工程师、材料科学家和化学家之间的互动。受生物学和生命科学的启发，教育影响的核心是创建粒子扩散机制的3D可视化。这一职业奖的研究目标是检查和了解纳米火山灰在水泥基复合材料中的分散机理。其核心假设是，除了提高水泥基基质中聚合物-颗粒单元之间的稳定力外，提高聚合物与纳米颗粒(100 Nm)之间的化学键能将导致更好的分散质量和基质的致密化。根据这一假设，本研究被细分为以下五个相互关联的研究目标：1)成分表征；2)聚合物合成与表征；3)颗粒-聚合物界面相互作用；4)纳米颗粒稳定化；5)混凝土密度评估。提出了一种多方法的研究方法来研究有趣的复杂分散机制。提出的研究的主要挑战是隔离互连机制以降低系统复杂性。受控聚合物合成和水泥基孔溶液的受控离子浓度是便于分离影响吸附动力学和分散机理的参数的例子。

This Faculty Early Career Development (CAREER) award will investigate the behavior and properties of nano-sized particles in cement-based materials. Nanoparticles have the potential to lead to more dense materials, and to carry over specific functionalities leading to novel material design possibilities, such as intelligent multi-functional highly durable engineered concretes. These design possibilities will allow for enhanced performance control and will increase the potential in effectively addressing the current poor condition of the nation's aging infrastructure as well as prepare for future infrastructure concerns. Unlocking the full potential of nano-sized particles in cement-based systems is currently held back by the limited understanding of the mechanisms by which they disperse throughout the concrete matrix. This information is critical for understanding and improving the strength and durability of the material. This award supports fundamental research to provide needed knowledge for high quality dispersion of nano-particles in cement-based systems. Meaningful impacts will be created through educational outreach activities by a) sharing newly gained knowledge for the advancement of the cement based technology, b) inspiring and motivating the next generation to pursue science, technology, engineering and mathematics (STEM), letting them discover their potential of creativity, and c) connecting knowledge of various science disciplines to enhance the interaction between civil engineers, materials scientists and chemists. Inspired by biology and life science, the centerpiece of the educational impact is creating 3D visualization of particle dispersion mechanisms. The research objective of this CAREER award is to examine and understand the dispersion mechanisms of nano-sized pozzolans in cement-based composites. The central hypothesis is that enhancing the chemical bond energy between polymer and nanoparticle (100 nm) in addition to improving the stabilization forces between polymer-particle units in cement based matrix will lead to better dispersion quality and densification of the matrix. In pursuit of this hypothesis the proposed research is subdivided into the following five interconnected research aims, 1) constituents characterization, 2) polymer synthesis and characterization, 3) particle-polymer interfacial interactions, 4) nanoparticle stabilization and 5) concrete density assessment. A multi-method investigation is proposed to study the intriguing complex dispersion mechanisms. The main challenge of the proposed research is to isolate interconnected mechanisms to reduce the system complexity. Controlled polymer synthesis and controlled ionic concentration of the cement based pore solution are examples of facilitating the isolation of parameters influencing adsorption kinetics and dispersion mechanisms.