Materials World Network: Polymers Dynamics in the Presence of Nanoparticles

这项研究有助于提供一个基本的理解聚合物动力学在纳米粒子的存在使用协调的实验和理论方法。这个来自宾夕法尼亚大学和杜伦大学的材料世界网络团队在聚合物纳米复合材料和动态特性方面拥有丰富的经验，他们正在共同探索这些迷人而复杂的材料中的聚合物扩散和流变性。该团队最近发现了一个引人注目的例子，说明聚合物在纳米粒子存在下的行为是如何不同的，其中聚合物扩散首先减慢，然后随着纳米粒子的加入而恢复。高分子纳米复合材料动力学研究主要集中在三个方面。(1)建立聚合物在纳米复合材料中扩散的潜在机制。各种各样的研究正在进行中，探索纳米颗粒/聚合物相互作用、纳米颗粒取向、聚合物和纳米颗粒直径的相对大小以及纳米颗粒形状的影响。(2)将聚合物和纳米颗粒扩散研究与流变学测量联系起来，包括线性粘弹性测量、零剪切粘度、平台模量和松弛时间。聚合物扩散和聚合物流变性通过基本弛豫参数密切相关，因此我们的目标是调和聚合物纳米复合材料中聚合物动力学的这两种测量。(3)完善和扩展了纳米粒子存在下聚合物动力学的理论描述。一个关键的扩展是调整粒子附近的单体摩擦系数，以评估焓相互作用对扩散的重要性。该研究团队在聚合物纳米复合材料物理学方面具有开创性的见解，这可能对新兴的聚合物纳米复合材料产业产生积极影响。互动包括会议、双月电话会议、月度报告、通过安全网站共享数据、定期国际旅行以及远程访问实验设备。该项目还通过为女性教师和研究生建立专业问题解决小组来解决女性在科学和工程领域的需求，作为集体应对科学和工程职业挑战和机遇的一种手段。此外，宾夕法尼亚大学和达勒姆大学的本科生参与了研究活动，并考虑了推出新材料的商业方面。这项材料世界网络研究由DMR聚合物项目和DMR特殊项目办公室支持。

This research helps provide a fundamental understanding of polymer dynamics in the presence of nanoparticles using a coordinated experimental and theoretical approach. This Materials World Network team from the University of Pennsylvania and Durham University has considerable experience in polymer nancomposites and dynamic properties, and is working together in exploring polymer diffusion and rheology in these fascinating and complex materials. This team recently found a dramatic example of how polymers behave differently in the presence of nanoparticles, wherein polymer diffusion first slowed and then recovered with the addition of nanoparticles. Research efforts are focusing on three aspects of polymer nanocomposite dynamics. (1) Establishing the underlying mechanism of polymer diffusion in nanocomposites. A variety of studies are underway that explore the impact of nanoparticle / polymer interactions, nanoparticle orientation, relative size of the polymer and nanoparticle diameter, and nanoparticle shape. (2) Relating the polymer and nanoparticle diffusion studies to rheological measurements including linear viscoelastic measurements, zero-shear viscosity, plateau modulus and relaxation times. Polymer diffusion and polymer rheology are intimately related through fundamental relaxation parameters, so our goal is to reconcile these two measures of polymer dynamics in polymer nanocomposites. (3) Refining and extending our theoretical description of the polymer dynamics in the presence of nanoparticles. One critical extension is to adjust the monomeric friction coefficient near the particles to evaluate the importance of enthalpic interactions on diffusion.The research team is well-positioned for groundbreaking insights into the physics of polymer nanocomposites that are likely to have a positive impact on the emerging industry of polymer nanocomposites. Interactions include meetings, bi-monthly teleconferences, monthly reports, data sharing via a secure website, regular international trips, and remote access to experimental equipment. This project also addresses the needs of women in science and engineering by establishing professional problem-solving groups for women faculty and graduate students as a means to collectively address the challenges and opportunities in science and engineering careers. Furthermore, undergraduates from both the University of Pennsylvania and Durham University participate in the research activities as well as consider the business aspects of launching new materials.This Materials World Network research is supported by the DMR Polymers Program and the DMR Office of Special Programs.