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

非技术总结这个职业奖支持理论和计算研究和教育，以阐明设计模仿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用于广泛的常见应用，从橡胶带到汽车的塑料部件到包装材料等等。PI的灵感来自于生物系统的复杂精度，这些生物系统由大分子组成，这些大分子使用静电电荷模式编码的信息进行专门和专门的相互作用。PI将研究自组织聚合物是否可以以类似的方式表现。PI的小组将决定如何沿着聚合物分子链沿着的静电荷单体的图案可以被设计成在纳米长度尺度上引导分子结构的自组织。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装在一起。为此，PI将考虑具有强烈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材料，称为复合凝聚层。这种“粘附”高度依赖于聚合物主链上沿着的电荷顺序，PI基团将确定不同的模式如何从聚阳离子与聚阴离子相互作用中出现。这一组装主题将推动需要纳米级结构精度的广泛材料类别的进步，如燃料电池膜、功能涂层和传感器以及药物输送载体，该项目的综合教育和推广部分支持更广泛地推广到代表性不足的少数群体，沿着研究生和本科生的研究培训和指导。推广工作包括将PI小组的计算机模拟进展纳入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学院内PI设计活动的核心内容。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。该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中一个重大挑战的关键：设计对刺激做出反应、编码信息并形成复杂结构的软材料。PI的团队将从生物聚合物中获得线索，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异性结合，并建立利用聚合物自组装的电荷图案所需的设计规则。在这项工作中，PI将系统地探索电荷序列如何决定带相反电荷的聚电解质之间的相互作用强度和特异性。这些聚合物的溶液进行缔合相分离成复杂的凝聚层，其作为连接电荷图案化到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测：1）控制相互作用强度的局部单体位置和模式，以及2）可通过互补序列促进相互作用特异性的轮廓长度电荷变化。这两个序列长度尺度将提供使用电荷序列编码自组装的基础。本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，使用模拟方法，该方法独特地适合于解决将单体水平序列连接到形态学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进行更广泛的外联，沿着研究生和本科生的研究培训和指导。推广工作包括将PI小组的模拟进展纳入聚合物可持续性和实验合作的背景下。交互式模拟是伊利诺伊大学圣埃尔莫布雷迪STEM学院内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.