Semi Fluorinated Polymers: Forming Energy Controlled Responsive Interfaces

技术摘要本提案旨在探索半氟化聚合物作为响应性自我修复界面的潜力。响应性界面在生物多样性中无处不在。从自清洁表面和粘合控制界面到自愈层，大自然激发了大量的努力来设计合成响应性聚合物界面。氟化和质子化的链段是高度不相容的，并且表现出非常不同的表面相互作用。因此，在聚合物链中插入一个短的氟化链段通常就足以诱导微相分离和长程有序。将高度不兼容的短段裁剪成一条链提供了一种获得接口的方法，该接口可以在本地重新排列并响应环境中的变化，同时保持层的完整性。可逆反应的驱动力在于任何系统达到热力学平衡的趋势。为了实现这一目标，这项研究将在可行的情况下识别和量化控制半氟化薄膜结构和界面特征的因素，研究这些复杂界面上的溶剂动力学，并确定它们形成界面以响应刺激的条件。拟议的研究将集中在三类半氟共聚物：a)碳氢化合物和含氟脂肪链，b)全氟环丁烷桥联的无规共聚物，以及c)聚苯乙烯和半氟硅氧烷嵌段的两嵌段共聚物。界面的结构和能量将通过显微镜和散射技术结合分子动态计算机模拟进行研究。与整体结构和动力学相比，这些测量将提供对有效设计响应界面至关重要的多重尺度图。非技术总结拟议的研究将影响新技术的发展，并为科学教育做出贡献。开发具有可控光学和导电特性以及选择性粘附性的响应性聚合物材料，对于设计从纳米生物传感器和植入物到塑料电子和自我修复涂层的下一代设备至关重要。拟议研究的结果将直接影响技术进步。PI与3M的科学家正在进行的合作将成为技术实施和结果测试的跳跃开始。克莱姆森将通过小企业倡议进一步探索交通运输的应用。随着在早期阶段认识到科学教育的重要性，拟议的研究将纳入为高中生设计的项目，并推导出向公众传播科学亮点的方法。该项目将与南卡罗来纳州格林维尔的两名高中教师一起完成，他们是来自河滨高中的大卫·多尔贝和来自格林维尔高中的威森豪特博士。在研究生层面，该项目将结合克莱姆森大学和国家实验室使用中子和X射线源进行的研究。传统的研究生教育将超越培养下一代材料研究人员，利用从中子和X射线技术中提取的独特信息来设计新材料。在这些技术的使用非常有限的情况下，这一点尤其重要。PI是她所在大学的第一位使用其中一些资源的科学家。这一倡议将促进克莱姆森科学家和国家实验室科学家之间的新合作。鉴于实验中子技术的最新发展，这一教育倡议具有进一步的意义，国家科学基金会提供了部分资金，允许探索新材料的反应。

TECHNICAL ABSTRACT The proposal seeks to explore the potential of semifluorinated polymers as responsive self healing interfaces. Responsive interfaces are ubiquitous in biological manifolds. From self cleaning surfaces and adhesion controlled interfaces to self healing layers, nature has inspired intensive efforts to design synthetic responsive polymeric interfaces. Fluorinated and protonated segments are highly immiscible and exhibit very different surface interactions. As a result, inserting a short fluorinated segment into a polymer chain is often sufficient to induce micro-phase separation as well as long range order. Tailoring highly incompatible short segments into one chain offers a means to obtain interfaces that can locally rearrange and respond to changes in the environment while retaining the integrity of the layers. The driving forces for reversible responses lie in the tendency of any system to achieve thermodynamic equilibrium. To attain this goal, the research will identify and quantify when feasible, the factors that control the structure and interfacial characteristics of thin semifluorinated films, study the dynamics of solvents at these complex interfaces and identify the conditions under which they form interfaces that respond to stimuli. The proposed study will focus on three groups of semifluorinated copolymers: a) hydrocarbons and fluorinated aliphatic chains, b) random co-polymer bridged by perfluoro cyclobutane, and c) diblock copolymers of polystyrene and semifluorinated siloxane blocks. The structure and energies of the interfaces will be studied by microscopy and scattering techniques accompanied by molecular dynamic computer simulations. These measurements, in comparison with the bulk structure and dynamics will provide a multiple length scale picture critical for effective design of responsive interfaces.NON TECHNICAL SUMMARYThe proposed research will impact the development of new technologies and contribute to science education. Developing responsive polymeric materials with controlled optical and conducting characteristics together with selective adhesion is essential for the design of next generation devices from nano-bio sensors and implants to plastic electronics and self healing coatings. The results of the proposed research will directly impact technological advancements. Ongoing collaboration of the PI with scientists at 3M will serve as a jump start for technological implementation and testing of the findings. Further applications of transport will be explored via small business initiatives at Clemson. With the realization of the significance of to science education at early stages, the proposed research will incorporate projects designed for high school students and derive ways to disseminate science highlights to the public. This will be done together with two high school teachers in Greenville SC, David Dollbey from Riverside High School and Dr. Wisenhunt from Greenville High School.On the graduate level, the project will incorporate studies at Clemson University and in national laboratories, using neutron and X-ray sources. The traditional graduate education will transcend to training the next generation of material researches to take advantage of the unique information extracted from neutron and X-ray techniques to the design of new materials. This is particularly significance in a state where the use of these techniques has been very limited. The PI is the first scientist from her University to use some of these resources. This initiative will foster new collaborations between Clemson scientists and those in national laboratories. This educational initiative in of further significance in view of recent developments in experimental neutron techniques, funded partially by the National Science Foundation, that allow probing the response of new materials.