CAREER: Developing the Design Rules of Charge Sequence to Inform Polymer Self-Assembly

该职业奖支持理论和计算研究和教育，以阐明设计模拟生物学的聚合物材料的规则。聚合物是由称为单体的分子单元连接而成的长链状分子。由聚合物制成的材料被广泛用于从橡皮筋到汽车塑料部件到包装材料等的常见应用中。PI的灵感来自于复杂精密的生物系统，这些系统由大分子组成，它们专门利用静电电荷模式编码的信息相互作用。PI将研究是否可以使自组织聚合物以类似的方式表现。PI的团队将决定如何设计沿着聚合物分子链的带静电单体的模式，以指导分子结构在纳米尺度上的自组织。聚合物的单体序列将是一种工具，可以像拼图一样将分子组合在一起。为了做到这一点，PI将考虑具有强吸引力的聚合物系统，因为它们由称为聚阳离子的正电荷链和称为聚阴离子的负电荷链组成。在溶液中，大量的这些聚阳离子和聚阴离子粘在一起，形成一种动态的凝胶状物质，称为复杂凝聚体。这种“粘附”高度依赖于聚合物主链上的电荷序列，而PI的研究小组将确定不同的聚阳离子与不同的聚阴离子相互作用如何产生不同的模式。这种组装基元将使需要纳米级结构精度的广泛材料取得进展，例如燃料电池膜、功能涂层和传感器以及药物输送工具。该项目的综合教育和外联部分支持向代表性不足的少数群体提供更广泛的外联服务，以及研究生和本科生的研究培训和指导。外联工作包括将PI小组的计算机模拟进展置于聚合物可持续性和实验合作的背景下。交互式计算机模拟是伊利诺伊大学圣埃尔莫·布雷迪STEM学院pi设计活动的核心。这项活动将向代表性不足的少数民族的小学生介绍塑料的生命周期和可持续性。本职业奖支持理论和计算研究和教育，旨在使用序列设计的聚合物来模拟生物大分子。序列控制是解决聚合物科学重大挑战的关键：设计对刺激作出反应的软材料，编码信息，形成复杂的结构。PI的团队将从生物聚合物中获取线索，这些生物聚合物由于编码在电荷单体序列中的信息而进行特定的结合，并建立利用聚合物自组装的电荷模式所需的设计规则。在这项工作中，PI将系统地探索电荷序列如何决定相反电荷的聚电解质之间的相互作用强度和特异性。这些聚合物的溶液经过结合相分离形成复杂的凝聚体，作为连接电荷模式与宏观相行为和纳米级组装的理想模型系统。蒙特卡罗模拟和混合粒子/场模拟方法将用于探索：1)控制相互作用强度的局部单体放置和模式，以及2)通过互补序列促进相互作用特异性的轮廓长度电荷变化。这两种序列长度尺度都为利用电荷序列编码自组装提供了依据。这项研究将阐明使用序列定义的聚合物来驱动聚合物设计的原理，使用独特的模拟方法来解决连接单体水平序列到形态或宏观现象的不同长度尺度。该项目的综合教育和外联部分支持向代表性不足的少数群体提供更广泛的外联服务，以及研究生和本科生的研究培训和指导。外联工作包括将PI小组的模拟进展置于聚合物可持续性和实验合作的背景下。交互模拟是伊利诺伊大学圣埃尔莫·布雷迪STEM学院pi设计活动的核心。这项活动将向代表性不足的少数民族的小学生介绍塑料的生命周期和可持续性。

NONTECHNICAL SUMMARYThis CAREER award supports theoretical and computational research and education to elucidate rules for designing polymeric materials that mimic biology. Polymers are long chain-like molecules that are made of joined molecular units called monomers. Materials made from polymers are used in a wide range of common applications from rubber bands to plastic components of automobiles to packaging materials and more. The PI is inspired by the sophisticated precision of biological systems which are made from large molecules that specifically and exclusively interact using information encoded in patterns of electrostatic charge. The PI will investigate whether polymers that self-organize can be made to behave in a similar way. The PI's group will determine how patterns of electrostatically charged monomers along a polymer molecular chain can be designed to guide the self-organization of molecular structures at the nanometer length scale. The monomer sequence of a polymer will be a tool to fit molecules together like puzzle pieces. To do this, the PI will consider polymer systems that strongly attract because they consist of chains of positive charge called polycations and chains of negative charge called polyanions. In solution, large numbers of these polycations and polyanions stick together in a dynamic, gel-like material known as a complex coacervate. This "sticking" is highly dependent on the sequence of charges along the polymer backbone, and the PI's group will establish how different patterns emerge from which polycations interact with which polyanions. This assembly motif will enable advances in a broad class of materials that demand structural precision at the nano-level, such as fuel cell membranes, functional coatings and sensors, and drug delivery vehicles.The integrated education and outreach component of this project supports broader outreach to underrepresented minority groups, along with graduate and undergraduate research training and mentorship. Outreach efforts consist of placing the computer simulation advances of the PI's group into the context of polymer sustainability and experimental collaboration. Interactive computer simulation is the centerpiece of a PI-designed activity within the St. Elmo Brady STEM Academy at the University of Illinois. This activity will introduce the lifecycle of plastics and sustainability to elementary-age students in underrepresented minorities. TECHNICAL SUMMARYThis CAREER award supports theoretical and computational research and education that seeks to use sequence-designed polymers to emulate biological macromolecules. Sequence control is key to addressing a grand challenge in polymer science: design soft materials that respond to stimuli, encode information, and form complex structures. The PI's group will take cues from biopolymers that undergo specific binding due to information encoded in charge monomer sequence, and establish the design rules needed to harness charge patterning for polymer self-assembly. In this work, the PI will systematically explore how charge sequence dictates the interaction strength and specificity between oppositely-charged polyelectrolytes. Solutions of these polymers undergo associative phase separation into complex coacervates, which serve as an ideal model system for connecting charge patterning to macroscopic phase behavior and nanoscale assembly. Monte Carlo simulation and hybrid particle/field simulation methods will be used to probe: 1) local monomer placement and patterns that will control interaction strength, and 2) contour-length charge variation that can promote interaction specificity via complementary sequences. Both sequence length scales will provide the basis for using charge sequence to encode self-assembly. This research will elucidate principles of using sequence-defined polymers to drive polymer design, using simulation methods uniquely suited to addressing the disparate length scales connecting monomer-level sequence to morphological or macroscopic phenomena. The integrated education and outreach component of this project supports broader outreach to underrepresented minority groups, along with graduate and undergraduate research training and mentorship. Outreach efforts consist of placing the simulation advances of the PI's group into the context of polymer sustainability and experimental collaboration. Interactive simulation is the centerpiece of a PI-designed activity within the St. Elmo Brady STEM Academy at the University of Illinois. This activity will introduce the lifecycle of plastics and sustainability to elementary-age students in underrepresented minorities.