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.

许多基本产品，例如，玻璃、纸、塑料和橡胶都是由聚合物制成的。聚合物由于其多功能性、低成本和可加工性而非常有吸引力，但其功能是有限的。为了增强聚合物的功能性和强度，建议掺入纳米颗粒。然而，大多数纳米颗粒通常与聚合物基质不相容，导致团聚和机械性能恶化。为了控制纳米粒子在聚合物基体中的分散，提出了在纳米粒子表面化学接枝聚合物，称为毛状纳米粒子。该奖项旨在了解毛状纳米颗粒如何影响聚合物的功能和性能。通过控制不同形状的分散良好的纳米颗粒上的接枝聚合物链长、密度和化学性质，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的教育和推广工作，如涉及本科研究人员，教师教育计划，并发布开源代码，以扩大其影响。含有毛状纳米颗粒的聚合物基质的流变学不能用已知的理论解释，例如，爱因斯坦的或学士的，这低估了相对粘度超过1000万倍。因此，该奖项的目的是（1）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学;（2）开发和验证模拟此类悬浮液的计算工具;（3）研究其偏离理论的主要原因，从而为先进制造需求改进理论/简化模型铺平道路。拟议的研究旨在制备设计的0 D，1D和2D纳米粒子接枝聚（甲基丙烯酸甲酯）或其他混溶性分子具有不同的链长和接枝密度分散在聚（甲基丙烯酸甲酯）矩阵。粒子分辨模拟将通过使用能够模拟与流体相互作用的任意形状粒子的锐界面浸没边界方法处理移动粒子来进行。将颗粒上的毛状接枝物建模为来自实验的相互作用区域上的多孔介质。模拟和实验将提供足够的相关性来测试几何参数对流变学影响的几个假设，从而使基于这些参数的经验公式的发展成为可能。该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。