SGER: Connecting the Depletion, Wetting, and Rheological Behaviors of Polymer Grafted Nanoparticles in Polymer Melts

建议编号：CTS-0649081主要研究员：Green，David L.从属关系：弗吉尼亚大学Main CamousProposal标题：SGER：连接聚合物接枝纳米粒子在聚合物熔体中的耗尽、润湿和流变行为拟议研究的目的是将耗竭絮凝和界面润湿的热力学与聚合物接枝纳米粒子分散到半稀和浓缩聚合物溶液中的动力学联系起来。采用自下而上的方法，由聚二甲基硅氧烷(PDMS)在聚二甲基硅氧烷(PDMS)溶液和熔体中接枝的二氧化硅纳米球组成的模型体系将被用来调节表征良好的纳米颗粒之间的相互作用。通过系统地控制各种参数，如PDMS在粒子表面的接枝密度和自由聚合物在溶液或熔体中的链长，可以实现这种调节。将进行详细的测量，以将相图与聚合物接枝纳米颗粒的流动行为联系起来，并将这些行为与自洽平均场模型的预测进行对比，以将实验与理论进行比较。这些结果将被用来确定优化先进材料最终使用性能的合理基础。BROADER影响：PI将利用本科生研究经验计划，为弗吉尼亚大学的工程学研究生学习建立一个代表不足的学生渠道。通过将这些项目针对特定的地理区域和人群，PI希望增加化学工程领域的女性和少数族裔博士的数量。

ABSTRACTProposal Number: CTS-0649081Principal Investigator: Green, David L.Affiliation: University of Virginia Main CamousProposal Title: SGER: Connecting the Depletion, Wetting and Rheological Behaviors of Polymer Grafted Nanoparticles in Polymer Melts The aim of the proposed research is to connect the thermodynamics of depletion flocculation and interfacial wetting to the dynamics of dispersing the polymer-grafted nanoparticles into semi-dilute and concentrated polymer solutions.INTELLECTUAL MERIT:The static and dynamic behaviors of the polymer-grafted nanoparticles will be studied in semi-dilute and concentrated polymer solutions to define a wide array of complex environments into which polymer-grafted nanoparticles are dispersed. Employing a bottom-up methodology, model systems consisting of polydimethylsiloxane (PDMS)-grafted silica nanospheres in PDMS solutions and melts will be used to regulate the interactions between the well-characterized nanoparticles. This regulation will be achieved by systematically controlling a variety of parameters such as the grafting density of PDMS on the particle surface and the chain length of the free polymer in the solution or melt. Detailed measurements will be made to connect the phase diagrams to the flow behaviors of the polymer-grafted nanoparticles and these behaviors will be contrasted against predictions from self-consistent mean-field models to compare experiment to theory. These results will be used to determine a rational basis for optimizing the end-use properties of advanced materials.BROADER IMPACT:The PI will utilize the Research Experience for Undergraduates program to establish a pipeline of underrepresented students for engineering graduate study at the University of Virginia. By targeting these programs to specific geographic areas and populations, the PI hopes to increase the number of woman and minority PhDs in chemical engineering.