RUI: Solution and Thin Film Properties of Dually Stimuli-Responsive Molecular Brush Block Copolymers

非技术总结了解聚合物的分子结构和其观察到的性能之间的基本关系，可以定制可能应用的性能。一种聚合物，已知显着改变性能，如溶解在水中的能力，响应于一个小的变化，在外部刺激，如温度和pH值，已被选定为详细的调查。通过改变该聚合物的结构以从该核聚合物产生梳状或瓶刷状分子结构并添加化学上不同的链段，预期将产生在溶液和薄膜中均具有独特性质的新聚合物材料。这些聚合物材料的特性可以针对潜在的应用进行定制，从而对社会有益，例如用于水净化和更好的靶向和定制药物递送的聚合物。这些材料将使用更环保的合成方法制备。这项工作产生的新知识将通过出版物，演示文稿和纳入本科课程与广大科学观众分享，并通过社区和K-12外展演示文稿向更广泛的观众分享。 该项目将为本科生，特别是材料科学和工程领域的女性提供全职沉浸式研究体验。这将鼓励更多的妇女在科学和工程领域攻读高级学位和从事研究工作。本项目的目的是确定嵌段和支化共聚物结构与刺激响应特性相结合对共聚物在溶液和薄膜中自组装的影响。刺激响应功能性导致性质如溶解度、粘度、粘弹性、界面活性和自组装的显著变化，而外部刺激的变化很小。支化和嵌段共聚物结构影响聚合物的性质，包括聚合物构象、链缠结行为、自组装和流变响应。具有嵌段和支化结构的刺激响应共聚物将使用通过电子转移原子转移自由基聚合（ARGET ATRP）再生的更环保的活化剂来合成。的pH值和温度响应的聚（（2-二甲基氨基）乙基甲基丙烯酸酯）（PDMAEMA）已被选为主要的刺激响应聚合物的调查，因为它改变溶解度和构象响应温度和pH值的变化。PDMAEMA的刺激响应功能将结合嵌段和支化的共聚物结构，以产生预期的独特的解决方案和薄膜性能的新材料。这些材料在光子学、药物递送和粘度调节剂中具有潜在的应用，包括对社会有益的应用，例如用于水净化的聚合物膜和更定制的药物递送系统。本科生研究合作者将充分参与本科研究的这种沉浸式高影响力体验。预计这将增加威斯康星大学奥克莱尔分校材料科学与工程专业本科女生的保留率，并鼓励更多女性攻读STEM高级学位和研究职业。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响力审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARYUnderstanding the fundamental relationships between a polymer's molecular structure and its observed properties allows customizing of the properties for possible applications. A polymer known to dramatically change properties, like the ability to dissolve in water, in response to a small change in an external stimulus, such as temperature and pH, has been selected for detailed investigation. By changing the structure of this polymer to create comb-like of bottlebrush-like molecular architectures from this core polymer and to add chemically distinct segments, it is expected that new polymeric materials will be generated with unique properties both in solution and in thin films. The properties of these polymeric materials can be tailored for potential applications with benefit to society such as polymers for water purification and better targeted and customized drug delivery. These materials will be prepared using a more environmentally benign synthetic approach. New knowledge generated from this work will be shared with a broad scientific audience through publications, presentations, and incorporation into the undergraduate curriculum, and to more general audiences through community and K-12 outreach presentations. This project will provide full-time immersive research experiences for undergraduate students, particularly for women in materials science and engineering. This will encourage more women to pursue advanced degrees and research careers in science and engineering. TECHNICAL SUMMARYThe objective of this project is to determine the effect of combining block and branched copolymer architectures with stimuli-responsive properties for the self-assembly of copolymers in solution and in thin films. The stimuli-responsive functionality results in dramatic changes in properties, such as solubility, viscosity, viscoelasticity, interfacial activity, and self-assembly, with a small change in external stimuli. Branched and block copolymer structures affect polymer properties including polymer conformation, chain entanglement behavior, self-assembly, and rheological responses. Stimuli-responsive copolymers with block and branched architectures will be synthesized using the more environmentally benign activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The pH- and thermo-responsive poly((2-dimethylamino)ethyl methacrylate) (PDMAEMA) has been selected as the primary stimuli-responsive polymer under investigation because it changes solubility and conformation in response to changes in both temperature and pH. The stimuli-responsive functionality of PDMAEMA will be combined with block and branched copolymer architectures in order to generate new materials with expected unique solution and thin film properties. These materials have potential applications in photonics, drug delivery, and viscosity modifiers, including applications that have benefit to society such as polymer membranes for water purification and more tailored drug delivery systems. Undergraduate student research collaborators will fully participate in this immersive high impact experience of undergraduate research. This is expected to increase the retention of undergraduate women in materials science and engineering at the University of Wisconsin-Eau Claire and to encourage more women to pursue advanced degrees and research careers in STEM.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.