CAREER: Functional Polymer Surfaces and Networks via Thiol-Click Chemistry

技术概述：合成聚合物化学的最新进展导致了许多基础科学发现，这些发现使开发具有独特和有用性能的材料成为可能。在一些值得注意的发现中，“点击”化学和随后的“稳健、高效、正交”策略正在彻底改变我们定制具有特定功能的聚合物材料的能力。这项CAREER提案利用了一类特殊的点击反应——“硫醇点击”——来解决聚合物表面工程和混合聚合物网络中尚未开发的领域，这将导致前所未有的表面功能控制和一套新的功能性玻璃聚合物网络。本CAREER提案的研究目标有三个方面：1)设计“反应性喷墨”和扫描近场光刻策略，利用多组分精密工程表面的高效硫醇-点击反应；2)通过正交硫醇-点击/苯并恶嗪化学合成并获得对一类新型杂化聚合物网络的基本理解；3)从根本上研究聚苯并噻嗪作为一类新型含硫醇热固性材料。为了实现这些目标，提出了以下具体的研究方向。1)通过巯基点击反应进行表面工程：PI将开发巯基点击反应，用于设计和制造图案，多组分聚合物表面。包括自由基介导的硫醇炔和碱催化的异氰酸硫醇、环氧硫醇和硫溴在内的正交策略使表面工程取得了进展。利用“反应性喷墨”和“湿式”近场光刻技术开发高效的硫醇点击反应，将提供在温和的生物相关条件下研究表面纳米级化学反应的能力。2)双交联硫醇-点击/苯并恶嗪混合网络：利用硫醇-点击反应，PI将设计并制备一类独特的双交联聚合物网络，包括一个初级硫醇-烯网络，该网络模板化了一个顺序的次级聚苯并恶嗪网络。除了独特的网络结构外，网络合成的顺序性为提供玻璃聚合物材料中网络形成和结构的基本知识提供了机会。3)新型聚苯并噻嗪网络的合成：将合成一类新的含硫醇的热固性聚合物，该聚合物由双（1,3-苯并噻嗪）单体衍生而来。聚苯并恶嗪的姊妹，这些聚合物包含一个噻吩/曼尼基桥骨架，表现出与聚苯并恶嗪本质上不同的性质。研究了氢键对网络结构和热力学性能的影响。非技术总结：本研究为利用高效正交化学方法制造多功能聚合物表面和杂化聚合物网络提供了一个强大的策略。这项研究的成功实施将为功能表面和网络提供途径，这将促进以下领域的进步：1)传感器、微流体、“智能”自清洁、防污表面；2)聚合物复合基质、粘合剂和高温涂层。这个职业的教育目标是实施一个综合的，发现驱动的教育平台，促进K -毕业生的聚合物科学和多样性。一项重要的外展计划包括：1)为一个由92%未被充分代表的少数民族组成的学区举办教师发展研讨会；2)一个高中工作影子/研究经验计划；3)一个旨在吸引/留住高分子科学专业学生的本科生参与计划。参与上述活动的研究生将经常有机会整合研究活动，以提高K - UG学生对聚合物科学的兴趣。研究生将通过综合的、多层次的方法，包括综合-先进的特征-建模策略，在技术相关领域进行培训和教育。这个综合的K -研究生教育和研究平台的最终结果是通过以下方式提供巨大的社会经济影响：1)鼓励不同人群的学生追求科学学科的职业生涯；2)通过提供对聚合物表面工程和网络的基本理解，建立科学发现和探索性应用之间的最短路径。

TECHNICAL SUMMARY: Recent advances in synthetic polymer chemistry have resulted in numerous fundamental scientific discoveries that have enabled the development of materials with unique and useful properties. Among notable discoveries, "click" chemistry and the ensuing "Robust, Efficient, Orthogonal" strategies are revolutionizing our ability to tailor-make polymeric materials with specific function. This CAREER proposal leverages a specific class of click reactions - "thiol-click" - to tackle unexplored areas in polymer surface engineering and hybrid polymer networks that will lead to unprecedented control of surface functionality and a novel set of functional glassy polymer networks. The research objectives of this CAREER proposal are three fold: 1) design "reactive inkjet" and scanning-near field lithography strategies that exploit high efficiency thiol-click reactions for multicomponent, precision engineered surfaces 2) synthesize and gain fundamental understanding of a new class of hybrid polymer networks via orthogonal thiol-click/benzoxazine chemistries, and 3) fundamentally investigate polybenzothiazines as a new class of thiol-containing thermosets. Towards achieving these objectives, the following specific research directives are proposed. 1) Surface Engineering via Thiol-Click Reactions: The PI will develop thiol-click reactions for the design and fabrication of patterned, multicomponent polymer surfaces. Orthogonal strategies involving radical-mediated thiol-yne and base-catalyzed thiol-isocyanate, thiol-epoxide and thiol-bromo enable advancements in surface engineering. Exploitation of high efficiency thiol-click reactions with "reactive inkjet" and "wet" near-field lithography will provide the ability to investigate nanoscale chemical reactions at surfaces under mild, biologically relevant conditions. 2) Dual-Crosslink Thiol-Click/Benzoxazine Hybrid Networks: Using thiol-click reactions, the PI will design and prepare a unique class of dual crosslinked polymer networks comprising a primary thiol-ene network which templates a sequential secondary polybenzoxazine network. Aside from unique network architectures, the sequential nature of network synthesis offers opportunities to provide fundamental knowledge of network formation and structure in glassy polymeric materials. 3) Synthesis of Novel Polybenzothiazine Networks: A new class of thiol-containing thermoset polymers derived from bis(1,3-benzothiazine) monomers will be synthesized. Sister to polybenzoxazines, these polymers comprise a thiophenol/Mannich-bridge backbone and exhibit properties substantially different from polybenzoxazines. The influence of hydrogen bonding on network structure and thermomechanical properties will be elucidated. NON-TECHNICAL SUMMARY: The proposed research offers a robust strategy for the fabrication of multifunctional polymer surfaces and hybrid polymer networks using highly efficient, orthogonal chemistries. Successful implementation of this research will provide access to functional surfaces and networks that will facilitate advancements in areas such as 1) sensors, microfluidics, and "smart" self-cleaning, antifouling surfaces and 2) polymer composite matrices, adhesives, and high temperature coatings. The educational objective of this CAREER is to implement an integrated, discovery-driven education platform that promotes polymer science and diversity from K - Graduates. A significant outreach program is proposed comprising 1) a teacher development workshop for a school district comprising 92% underrepresented minorities, 2) a high school job shadow/research experience program, and 3) an undergraduate engagement program that aims to attract/retain polymer science majors. Graduate students involved in each of the above outreach activities will be given frequent opportunities to integrate research activities to grow interest in polymer science for K - UG students. Graduate students will be trained and educated in technologically relevant areas via a comprehensive, multilevel approach involving synthesis-advanced characterization-modeling strategies. The ultimate outcome of this integrated K - Graduate education and research platform is to provide a large socio-economic impact by 1) encouraging a diverse population of students to pursue careers in scientific disciplines and 2) by providing the fundamental understanding of polymer surface engineering and networks necessary to establish the shortest paths between scientific discovery and exploratory applications.