NSF-BSF: Tapered Bottlebrush Block Copolymers: Synthesis, Solution Self-Assembly, and Simulations

非技术摘要：在材料研究部聚合物项目的资助下，弗吉尼亚理工大学的John B.Matson教授和以色列Ben-Gurion大学的Ronit Bitton教授领导了一个团队，创造出呈圆锥形的新型聚合物。锥形聚合物在溶液中的行为和相互作用目前尚不清楚，因为合成这些聚合物的方法是最近才开发出来的。这项工作很重要，因为聚合物在水中相互作用，形成尺寸在1-100纳米范围内的聚集体，应用广泛，但缺乏关于锥体形状如何影响聚集体形状和大小的基础研究。研究小组将依靠一种方法，将聚合物合成、纳米级聚集体的表征和聚集体的计算机模拟联系起来，以产生描述这些独特的聚合物在水中的行为的理论。总而言之，这些努力将推动聚合物自组装领域的发展，为生物医学、催化、食品科学和其他领域的聚合物应用设计提供潜在的好处。由于NSF-BSF提案的协作性和跨文化方面，这一平台将在弗吉尼亚科技传播科学中心的协助下用于加强科学交流。这项提案的校外教育目标集中在为弗吉尼亚州西南部的4-8年级学生加强青年体验科学(YES)计划。技术摘要：这个NSF-BSF项目专注于锥形两亲性瓶刷嵌段共聚物(BCP)，这是一种接枝聚合物，具有高接枝密度，设计为近似圆锥形。这项工作结合了一种综合的方法来合成、表征和模拟锥形瓶刷BCP。合成工作将依靠开环复分解(ROMP)接枝方法来制造各种锥形瓶刷BCP，主链和侧链的聚合度不同。将使用一系列表征技术系统地研究锥形瓶刷BCP的溶液自组装，包括电子显微镜和小角X射线和中子散射(SAXS，SANS)。建模研究将包括反馈回路中的粗粒度模型，以解释观察到的形态并建议新的锥形瓶刷BCP，这些BCP可以自组装成独特的或意想不到的溶液形态。该项目的中心假设是锥形瓶刷BCP的锥角将影响自组装的形态和尺寸分布。这种合成-表征-建模方法的预期结果包括发现锥角如何影响聚合物自组装，最终揭示聚合物结构如何影响材料性能的新理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARY:With funding from the Polymers Program of the Division of Materials Research, Professor John B. Matson of Virginia Tech and Prof. Ronit Bitton of Ben-Gurion University in Israel lead a team that is creating new polymers that take on a conical shape. How cone-shaped polymers behave and interact in solution is currently unknown because methods to synthesize these polymers were only recently developed. This work is important because polymers that interact in water to form aggregates on the size range of 1-100 nanometers are used in a variety of applications, but fundamental studies on how cone shape influences aggregate shape and size are lacking. The research team will rely on an approach that connects polymer synthesis, characterization of nanometer-scale aggregates, and computer simulations of aggregates to generate theories describing how these unique polymers behave in water. Collectively, these efforts will advance the field of polymer self-assembly, offering potential benefits in the design of polymers for applications in biomedicine, catalysis, food science, and other areas. Due to the collaborative and cross-cultural aspects of this NSF-BSF proposal, this platform will be used to enhance scientific communication with assistance from the Virginia Tech Center for Communicating Science. Off-campus educational goals of this proposal focus on enhancing the Youth Experiencing Science (YES) program for 4th–8th graders in southwestern Virginia.TECHNICAL SUMMARY:This NSF-BSF project focuses on tapered amphiphilic bottlebrush block copolymers (BCPs), which are graft polymers with high grafting density designed to take on an approximately conical shape. The work incorporates an integrated approach to the synthesis, characterization, and simulations of tapered bottlebrush BCPs. Synthetic efforts will rely on ring-opening metathesis (ROMP) grafting-through methods to make a wide range of tapered bottlebrush BCPs with variable degrees of polymerization for the backbone and side chains. The solution self-assembly of tapered bottlebrush BCPs will be systematically investigated using a range of characterization techniques including electron microscopy and small-angle X-ray and neutron scattering (SAXS, SANS). Modeling studies will include coarse-grained models, in a feedback loop, to explain the observed morphologies and suggest new tapered bottlebrush BCPs that could self-assemble into unique or unexpected solution morphologies. The central hypothesis for this project is that the cone angle of the tapered bottlebrush BCPs will influence self-assembled morphology and size distribution. Expected outcomes from this synthesis–characterization–modeling approach include discovering how cone angle influences polymer self-assembly, ultimately revealing new understanding of how polymer structure influences material properties. .This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.