Rheology of Polymer Melts with Designed Hairy Nanoparticles

设计毛状纳米粒子的聚合物熔体流变学

• 批准号: 2323413
• 负责人: Hung-Jue Sue
• 金额: $ 45万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2323413&HistoricalAwards=false
• 关键词: Rheology; Polymer; Melts; Designed; Hairy

Many essential products, e.g., glass, paper, plastics, and rubbers, are made of polymers. Polymers are highly attractive due to their versatility, low-cost and processability, but their functionality is limited. To enhance the functionality and strength of polymers, it is proposed to incorporate nanoparticles. However, most nanoparticles are often incompatible with polymer matrices, resulting in agglomeration and deterioration in mechanical properties. To control the dispersion of nanoparticles in polymer matrices, chemically grafted polymers on the surface of nanoparticles, known as hairy nanoparticles, is proposed. This award seeks to understand how hairy nanoparticles affect the functionality and properties of the polymers. By controlling the grafted polymer chain length, density, and chemical nature on well-dispersed nanoparticles of different shapes, the research can impact how polymers are manufactured, processed, and utilized for many engineering applications. The proposed research is accompanied by a series of educational and outreach efforts such as involving undergraduate researchers, educational programs for teachers, and releasing open-source codes, to broaden its impact. The rheology of polymer matrices containing hairy nanoparticles cannot be explained by known theories, e.g., Einstein’s or Bachelor’s, which underestimates the relative viscosity by over 10 million folds. The objective of this award, therefore, is to (1) experimentally investigate the rheology of nanocomposites with different shapes of hairy nanoparticles; (2) develop and validate computational tools to simulate such suspensions; and (3) investigate the main reasons for their deviation from the theory, thereby pave the way to improve theoretical/simplified models for advanced manufacturing needs. The proposed study intends to prepare designed 0D,1D, and 2D nanoparticles grafted by poly(methylmethacrylate) or other miscible molecules with different chain lengths and graft densities for dispersion in poly(methylmethacrylate) matrix. Particle-resolved simulations will be performed by handling the moving particles using a sharp-interface immersed boundary method, capable of simulating arbitrary-shaped particles interacting with the fluid. The hairy grafts on the particles will be modeled as a porous medium over the interaction zone derived from experiments. The simulations and experiments will provide sufficient correlation to test several hypotheses on the effect of geometric parameters on rheology, thereby enabling the development of empirical formulas based on these parameters.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.

许多重要产品，例如玻璃、纸张、塑料和橡胶，都是由聚合物制成的，由于其多功能性、低成本和可加工性而极具吸引力，但它们的功能是有限的。建议掺入纳米颗粒，然而，大多数纳米颗粒通常与聚合物基体不相容，导致团聚和机械性能恶化，以控制纳米颗粒在聚合物中的分散。该奖项旨在通过控制接枝聚合物的链长、密度和化学性质来了解毛状纳米颗粒如何影响聚合物的功能和性能。不同形状的分散良好的纳米颗粒，该研究可以影响聚合物的制造、加工和用于许多工程应用的方式。拟议的研究伴随着一系列教育和推广工作，例如涉及本科生的研究。包含毛状纳米粒子的聚合物基质的流变学无法用已知的理论（例如爱因斯坦理论或学士理论）来解释，这些理论将相对粘度低估了超过 1000 万倍。因此，该奖项的目的是（1）通过实验研究具有不同形状的毛状纳米颗粒的纳米复合材料的流变性；（2）通过计算进行开发和验证；模拟此类悬浮液的工具；(3) 研究其偏离理论的主要原因，为改进理论/简化模型以满足先进制造需求铺平道路。通过聚（甲基丙烯酸甲酯）或具有不同链长和接枝密度的其他可混溶分子在聚（甲基丙烯酸甲酯）基质中的分散，将通过以下方法进行颗粒解析模拟。使用锐界面浸没边界方法处理移动颗粒，能够模拟任意形状的颗粒与流体的相互作用，颗粒上的毛状接枝物将被建模为来自实验的相互作用区域上的多孔介质。将提供足够的相关性来测试几何参数对流变学影响的几种假设，从而能够开发基于这些参数的经验公式。该奖项反映了法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持以及更广泛的影响审查标准。