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

摘要提案编号：CTS-0649081主要研究者：绿色，大卫L.附属机构：弗吉尼亚大学主校区提案标题：SGER：连接耗尽，聚合物接枝纳米粒子在聚合物熔体中的润湿和流变行为本研究的目的是将耗尽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分散体系中的动力学联系起来。智力优势：聚合物接枝的纳米颗粒的静态和动态行为将在半稀释和浓缩聚合物溶液中进行研究，以确定聚合物接枝的纳米颗粒分散的各种复杂环境。采用自下而上的方法，模型系统组成的聚二甲基硅氧烷（PDMS）接枝的二氧化硅纳米球在PDMS溶液和熔体将被用来调节良好的表征纳米粒子之间的相互作用。这种调节将通过系统地控制各种参数来实现，例如颗粒表面上PDMS的接枝密度和溶液或熔体中游离聚合物的链长。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连接起来，并且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一个合理的基础，优化先进材料的最终使用性能。更广泛的影响：PI将利用本科生项目的研究经验，为弗吉尼亚大学的工程研究生课程建立一个代表性不足的学生管道。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女性和少数民族博士的数量。

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.