CAREER: Multiscale Modeling of Gas-assisted Synthesis and Properties of Porous Nanocomposite Materials

由陶瓷涂层覆盖的细颗粒或纤维组成的多孔材料有潜力在超轻和多功能航空航天结构、电能产生、转换和储存、气体分离和净化、柔性电子、光学和生物医学应用等领域取得关键进展。新的合成和加工方法可以为形成具有可调性能的多孔纳米材料提供精确、可控的途径。然而，影响陶瓷涂层生长和合成材料性能的因素在很大程度上仍然是未知的。该学院早期职业发展（Career）奖支持开发一种计算模型的研究，该模型能够在材料合成参数、原始纳米颗粒的结构和性能以及合成材料的性能之间建立联系。该研究将与教学活动相结合，旨在为下一代劳动力的工程师和研究人员提供专业准备。该奖项支持的研究目标是开发一种新的多尺度方法，用于气体辅助合成多孔纳米复合材料的预测模拟，多孔纳米复合材料由纳米颗粒或纳米纤维支架与陶瓷涂层组成，并表征其性能。这种方法的出现将为计算机辅助设计和按需调整多孔纳米复合材料的性能铺平道路。一系列原子模拟预测了核/壳纳米粒子和纳米管的力学和热性能，并用于参数化计算方法的三个主要组成部分，包括气体在随机介孔和大孔材料中的扩散和热传递的动力学模型，纳米颗粒表面陶瓷涂层的瞬态生长的动力学蒙特卡罗模型，并建立了纳米复合材料力学变形和热输运的动态细观模型。计算实验项目旨在揭示多孔材料的传质和传热的基本性质以及气体辅助材料合成的具体特征。虚拟合成纳米复合材料的机械和热传输性能将通过一系列测试来表征，这些测试主要关注界面载荷和热传递对材料弹性模量、断裂韧性和导热性的影响。

Porous materials composed of fine particles or fibers covered by ceramic coatings have the potential to allow critical advances in the fields of ultra-lightweight and multifunctional aerospace structures, electric energy generation, conversion and storage, gas separation and purification, flexible electronics, optics, and biomedical applications. New methods of synthesis and processing can provide precise, controllable routes to forming porous nanomaterials with tunable properties. The factors affecting the growth of ceramic coatings and performance of synthesized materials, however, remain unknown to the large extent. This Faculty Early Career Development (CAREER) award supports research on the development of a computational model capable of establishing a link between parameters of the material synthesis, structure and properties of raw nanoparticles, and properties of the synthesized materials. The research will be integrated with the teaching activity, targeted at the professional preparation of engineers and researchers for the next generation workforce.The goal of the research supported by this award is to develop a novel multiscale methodology for predictive simulation of gas-assisted synthesis of porous nanocomposites, composed of a scaffold of nanoparticles or nanofibers with ceramic coatings, and characterization of their properties. The emergence of this methodology will pave the way to computer-aided design and on-demand tuning of properties of porous nanocomposites. A series of atomistic simulations predicting mechanical and thermal properties of core/shell nanoparticles and nanotubes will be performed and used to parameterize three major components of the computational approach including the kinetic model of the gas diffusion and heat transfer through random meso- and macroporous materials, kinetic Monte Carlo model of transient growth of ceramic coatings on the nanoparticle surfaces, and dynamic mesoscopic model of mechanical deformation and thermal transport in the nanocomposites. The program of computational experiments will be targeted at revealing fundamental properties of the mass and heat transfer in porous materials and specific features of the gas-assisted material synthesis. The mechanical and thermal transport properties of virtually synthesized nanocomposites will be characterized in a series of tests focused on the effects of the interfacial load and heat transfer on the material elastic moduli, fracture toughness, and thermal conductivity.