Materials World Network: Dynamics in Polymer Nanocomposites Containing Hard, Soft and Mobile Nanoparticles

聚合物纳米复合材料，即分散在聚合物基体中的纳米颗粒混合物，自 20 世纪 90 年代初期推出以来，迅速引起了工业和基础研究的关注。丰田中央研究中心提供了首批高冲击应用之一，他们证明添加少量层状硅酸盐可以极大地提高尼龙的机械性能。事实上，具有改进的弹性模量、导电性、阻燃性和导热性的聚合物纳米复合材料的商业用途正在许多经济领域进行探索，包括航空航天、电子和体育应用。这项研究的主要目的是使用协调的实验和理论方法提供球形纳米粒子存在下聚合物动力学的基础知识。该提议的材料世界网络包含纳米颗粒合成、纳米复合材料制造、成像、深度分析、模拟、理论和中子散射方面的专业知识，以解决尺寸与单个聚合物相当或小于单个聚合物的纳米颗粒的存在如何影响动力学。该 MWN 团队在聚合物纳米复合材料方面拥有丰富的经验，并致力于共同探索聚合物扩散如何与这些引人入胜且具有商业重要性的材料的结构相关联。所提议的材料世界网络处于有利位置，可以对聚合物纳米复合材料的物理学产生突破性的见解，这可能对聚合物纳米复合材料的新兴行业产生积极的影响。虽然我们提出的研究将集中于球形纳米颗粒，但我们的研究结果将适用于更广泛的纳米颗粒。在设计纳米复合材料的制造方法时，了解聚合物动力学尤为重要。当含有高浓度纳米颗粒的母料与纯聚合物熔融混合时，聚合物扩散速率对于建立均匀浓度至关重要。例如，平衡纳米颗粒的高成本与其有吸引力的特性的一种策略是用纳米颗粒涂覆乳胶颗粒，然后烧结颗粒以获得良好的界面强度。材料强度由聚合物在界面区域相互扩散形成缠结决定，其机制将由拟议的研究建立。

Polymer nanocomposites, namely mixtures of nanoparticles dispersed in a polymer matrix, have gained rapid attention for both industrial and fundamental studies since their introduction in the early 1990's. One of the first high impact applications was provided by Toyota Central Research who demonstrated that the addition of a small amount of layered silicate greatly improved the mechanical properties of nylon. In fact, the commercial use of polymer nanocomposites with improved elastic modulus, electrical conductivity, flame retardation and thermal conductivity is being explored across many economic sectors including aerospace, electronics, and sporting applications. The main objective of this research is to provide fundamental knowledge of polymer dynamics in the presence of spherical nanoparticles using a coordinated experimental and theoretical approach. This proposed Materials World Network contains expertise in nanoparticle synthesis, nanocomposite fabrication, imaging, depth profiling, simulation, theory and neutron scattering to address how the presence of nanoparticles with sizes comparable to, and smaller than, the individual polymers impacts on dynamics. This MWN team has considerable experience in polymer nancomposites and is committed to working together to explore how polymer diffusion is correlated with structure in these fascinating and commercially-important materials.The proposed Materials World Network is well-positioned for groundbreaking insights into the physics of polymer nanocomposites that are likely to have positive impact on the emerging industry of polymer nanocomposites. While our proposed research will focus on spherical nanoparticles, our findings will be applicable to a broader range of nanoparticles. Understanding the polymer dynamics is particularly important when designing fabrication methods for nanocomposites. When a master batch containing a high concentration of nanoparticles is melt mixed with a neat polymer, the rate of polymer diffusion is critical for establishing a homogeneous concentration. For example, one strategy for balancing the high cost of nanoparticles with their attractive properties involves coating latex particles with nanoparticles and then sintering the particles to achieve good interfacial strength. The material strength is determined by the interdiffusion of polymers across the interfacial region to form entanglements and the mechanism for this will be established by the proposed research.