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

这个职业项目的重点是发展对软聚合物颗粒通过纳米级孔（称为易位）运动背后的基础科学的理解。这种运动是自然界许多过程的基础，具有深远的影响和应用——无论是作物的病毒感染导致粮食短缺和饥饿，还是使用多孔膜净化水。这项研究特别侧重于研究当聚合物附着在粒子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比其他类似大小的粒子更有利于易位的新型粒子。对这些新粒子的测量将有助于软粒子易位理论的发展，并扩大其应用范围。作为美国下一代科学标准的一部分，微软HoloLens将开发和使用用于聚合物教育的HoloLens，这是一门关于聚合物建模和可视化的新课程，培训了总共10名高中生，培训了大约100名中学教师进行基于探究的教育。展望未来，拟议的研究、教育和推广活动将对社会的重要领域，如有效的水净化和粮食来源安全，具有相关性和影响力。技术总结：该项目将研究共通性和n-聚类对聚合物纳米颗粒通过单一、强限制性纳米孔运输的影响。共溶性和n-聚类是尽管聚合物和溶剂之间存在非常有利的相互作用，但聚合物坍塌和聚集的溶液现象。如果理解并有目的地操纵，这些独特的行为可以产生模仿生物系统的软材料，并以“强方式”表现——比如对弱刺激做出反应的颗粒，通过孔进行实质性的结构重排。这些行为将导致使用弱刺激来控制软颗粒流动的简单机制。该项目的主要目标是：1)合成新型纳米颗粒，利用聚（n-异丙基丙烯酰胺）的n-聚类和共通性，对几何约束有良好的反应。2)采用综合计算和实验方法，研究和发展软颗粒通过裸孔转运的综合理论。3)利用大数据分析定量验证我们的假设，并提取变量之间额外的隐藏关系。4)利用微软HoloLens和3D打印技术，通过交互式可视化技术改造聚合物教育，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。分子/粒子的运动将通过溶液池上的离子电流测量来监测，纳米粒子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）将用于模拟纳米粒子的穿越。

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.