CAREER: Strong Responses in Weak Systems -- Movement of Soft Polymeric Nanoparticles through Confining Nanopores

非技术性总结这个职业项目的重点是发展背后的软聚合物颗粒在纳米级（称为易位）通过孔隙运动的基础科学的理解。这种运动对于自然界中的许多过程都是至关重要的，并且具有深远的影响和应用-无论是与导致粮食短缺和饥饿的作物病毒感染有关，还是与使用多孔膜净化水有关。这项研究特别侧重于研究聚合物附着在颗粒表面时发生的新的和独特的效应，并研究如何利用这些效应来创造新类型的颗粒，这些颗粒比其他类似尺寸的颗粒更有利于易位。 对这些新粒子的测量将有助于软粒子移位理论的发展，并拓宽其应用范围。补充教育和推广活动将导致开发和使用Microsoft HoloLens用于聚合物教育，聚合物建模和可视化的新课程，总共培训10名高中学生，以及培训大约100名中学教师探究式教育，作为美国下一代科学标准的一部分。展望未来，拟议的研究、教育和外联活动将对有效的水净化和粮食来源安全等重要社会领域产生相关和影响。技术总结PI将研究共溶和n-聚簇对聚合物纳米颗粒通过单个强限制性纳米孔的运输的影响。共溶和n-聚簇是聚合物在溶液中的一种现象，尽管聚合物和溶剂之间存在非常有利的相互作用，但聚合物仍会坍塌和聚集。如果理解并有目的地操纵，这些独特的行为可以产生模拟生物系统的软材料，并以“强烈的方式”表现-例如对弱刺激做出反应的颗粒进行实质性的结构重排以穿过孔隙。这些行为将导致简单的机制来控制软粒子的流动，只使用弱刺激。该项目的主要目标是：1）合成新的纳米粒子，利用聚（N-异丙基丙烯酰胺）的n-簇和cononsolvency有利地响应几何约束。2）调查和开发一个全面的理论软颗粒通过裸孔易位使用综合计算和实验方法。3)使用大数据分析来定量验证我们的假设，并提取变量之间的其他隐藏关系。4）通过使用Microsoft HoloLens和3D打印技术的交互式可视化技术来转变聚合物教育，以吸引和激励大学生、K-12教育工作者和其他人参与科学探索。纳米颗粒的特性将通过光散射、中子散射和电子显微镜来确定。耗散粒子动力学（DPD）将被用来模拟纳米粒子的遍历。

NON-TECHNICAL SUMMARYThis CAREER project focuses on developing an understanding of the fundamental science behind the movement of soft polymeric particles through pores at the nanoscale level (called translocation). Such movement is fundamental to many processes in nature, and has far-reaching impacts and applications -- whether it pertains e.g. to viral infection of crops leading to food shortages and starvation, or to purification of water using porous membranes. This research specifically focuses on studying new and unique effects that occur when polymers are attached to the surface of a particle, and investigates how these effects can be used to create new types of particles that favor translocation over other particles of similar sizes. Measurements of these new particles will help in the development of a theory for soft particle translocation and broaden the range of applications. The complementary education and outreach activities will result in the development and use of the Microsoft HoloLens for polymer education, a new course in polymer modeling and visualization, the training of a total of 10 high school students, and the training of approximately 100 middle school teachers in inquiry-based education as part of the Next Generation Science Standards in the United States. Looking to the future, the proposed research, education, and outreach activities will be relevant and influential to vital areas of society such as efficient water purification and food-source security. TECHNICAL SUMMARYThe PI will investigate the impact of cononsolvency and n-clustering on the transport of polymeric nanoparticles through a single, strongly confining nanopore. Cononsolvency and n-clustering are solution phenomena in which polymers collapse and aggregate despite the presence of very favorable interactions between the polymers and solvent. If understood and purposefully manipulated, these unique behaviors can yield soft materials that mimic biological systems and behave in "strong ways" -- such as particles that respond to weak stimuli to undergo substantial structural rearrangement to traverse a pore. These behaviors will lead to simple mechanisms for controlling the flow of soft particles using only weak stimuli. The primary objectives of this project are to: 1) Synthesize new classes of nanoparticles that exploit n-clustering and cononsolvency of poly(N-isopropylacrylamide) to respond favorably to geometrical confinement.2) Investigate and develop a comprehensive theory of the translocation of soft particles through bare pores using an integrated computational and experimental approach. 3) Employ big-data analytics to quantitatively verify our hypotheses and extract additional hidden relationships between variables.4) Transform polymer education with interactive visualization techniques using both the Microsoft HoloLens and 3D printing technologies to engage and motivate university students, K-12 educators, and others in scientific exploration.Molecular/particle movement will be monitored with ionic current measurements on a solution cell, nanoparticle characteristics will be determined by light scattering, neutron scattering, and electron microscopy. Dissipative particle dynamics (DPD) will be used to model nanoparticle traversal.