NSF-Europe Materials Collaboration: Synthesis, Characterization and Molecular Modeling of Stimulus-Responsive Polymer Brushes on Surfaces

该项目的目标是设计，制造和表征新颖的，刺激响应的聚合物刷，可以在分子长度尺度上进行控制。为了充分利用这些刺激响应聚合物刷纳米结构的潜力，需要了解分子尺度结构特征如何影响构象性质和水合动力学。此外，需要设计出有效的方法来将这种分子功能赋予各种表面。需要具有可控链长、表面密度和表面结构的模型体系，并结合理论模型和实验方便的方法来研究这些聚合物体系的构象力学。拟议的研究通过在杜克大学、隆德大学和乌普萨拉大学中子研究实验室（NFL）之间强有力的国际合作框架内解决三个具体目标来满足这些需求。2 .利用QCM-D/椭偏仪和中子反射测量表征分子结构对电刷构象和构象动力学的影响。通过实验和建模研究聚合物刷纳米结构中的横向相互作用。这些活动的结果将有助于从根本上理解刺激响应聚合物刷和表面纳米结构的结构-性能关系。更广泛的影响和国际合作在更大的背景下，在两个相互关联的建议中概述的活动是针对工程和控制纳米结构聚合物表面的三维表面化学和形貌。使用强大的表征技术，如NR，将阐明分子结构对共聚物刷的构象行为的作用，并可能导致刺激响应聚合物刷的设计指南。而提出的QCMD和椭圆偏振测量的组合可能具有更深远的影响，因为它可能应用于生物分子识别系统，因为组合测量将揭示配体结合时构象动力学和水合状态变化的见解。分子建模将开发工具，可用于预测和设计纳米结构聚合物表面的构象响应。拟议的研究为进一步建立和加强隆德大学和杜克大学之间的研究和教育联系提供了一个很好的机会。从提出的活动范围来看，很明显，该研究是跨学科的，除了材料表征和合成方面的新概念外，还清楚地解决了基本的高分子材料现象。拟议活动的范围与参与者的综合专业知识极为匹配。拟议项目的一个重要目标是学生和初级研究人员（博士后）参与国际研究和教育经验。两所大学的管理部门承诺认可合作大学学生的研究和课程学分。双方计划进行长期的相互访问，这将加强科学合作，同时也提供一种机制，使学生和初级研究人员接触到国外重要的文化体验。

INTELLECTUAL MERITSThe objective of the project is to design, fabricate and characterize novel, stimulus-responsivepolymer brushes that can be controlled on the molecular length scale. To capitalize on the potential of these stimulus-responsive polymer brush nanostructures, there is a need to understand how molecularscale structural characteristics influence the conformational properties and the hydration dynamics. Furthermore, efficient methods need to be devised to impart this molecular functionality to a variety of surfaces. Model systems with controlled chain length, surface density and surface structure are required in conjunction with theoretical models and experimentally convenient methods to study the conformational mechanics of these polymer systems. The proposed research addresses these needs by tackling three specific aims in the framework of a strong, international collaboration between Duke University, Lund University and the Neutron Research Laboratory (NFL) at Uppsala University.SA 1: Synthesis of new, stimulus-responsive brushes and nanostructuresSA 2:Characterization of the effect of molecular architecture on brush conformation and conformational dynamics using QCM-D/ellipsometry and neutron reflection measurements.SA 3: Study of lateral interactions in polymer brush nanostructures through experiments and modeling The results from the proposed activities will contribute significantly to the fundamental understanding of structure-property relationships in stimulus-responsive polymer brushes and nanostructures on surfaces.BROADER IMPACTS AND INTERNATIONAL COLLABORATIONIn a larger context, the activities outlined in the two interlinked proposals are directed atengineering and controlling the surface chemistry and topography of nanostructured polymeric surfaces in three dimensions. The use of powerful characterization techniques, such as NR, will illuminate the role of molecular architecture on the conformation behavior of copolymer brushes and will likely result in design guidelines for stimulus-responsive polymer brushes. Whereas the proposed combination of QCMD and ellipsometry measurements potentially has more far reaching impact, as it likely can be applied to biomolecular recognition systems, were the combined measurement will reveal insight into the conformational dynamics and the changes in the hydration state upon ligand binding. Molecular modeling will develop tools that can be used to predict and design the conformational response of nanostructured polymeric surfaces.The proposed research offers a great opportunity to further establish and strengthen a researchand education linkage between Lund University and Duke University. From the range of activitiesproposed it is clear that the research is interdisciplinary and clearly addresses fundamental polymermaterials phenomena, in addition to novel concepts in materials characterization and synthesis. The scope of the proposed activities is extremely well matched with the combined expertise of the participants. A significant objective of the proposed project is the involvement of student and junior researchers (post docs) in an international research and education experience. The administration of both universities pledged to accredit research and class credits taken by students at the respective partner university. Mutual, extended visits are planned that will strengthen the scientific collaboration but also provide a mechanism to expose students and junior researchers to a significant cultural experience abroad.