Understanding In-Situ Chemical Transformations of Polymer Brush-Modified Surfaces

了解聚合物刷改性表面的原位化学转化

• 批准号: 1133320
• 负责人: S Michael Kilbey
• 金额: $ 30万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1133320&HistoricalAwards=false
• 关键词: Understanding; Situ; Chemical; Transformations; Polymer

ABSTRACT#1133320Kilbey, S. MichaelUNDERSTANDING IN-SITU CHEMICAL TRANSFORMATIONS OF POLYMER BRUSH-MODIFIED SURFACESThe overarching goal of this advanced materials research is to understand how the ability to transform surface-attached polymeric layers so-called polymer brushes by chemical reaction is impacted by properties such as surface density, extent of the chains tethered at the interface, size of the functionalizing agent present in free solution, and reaction time and conditions. While reactive polymer brushes are of widespread interest, design rules that guide selection of appropriate conditions for integrating functional groups remain undeveloped and largely unexplored. To address this gap in knowledge, reactive polymer brushes will be created and modified in situ, and the ability of the chemically-modified interfacial layers to nucleate the growth of mineral phases will also be investigated. All of these studies will enhance the design of functional polymeric interfacial coatings, leading to new long term opportunities for the design of biomaterial scaffolds for cell growth, active layers in sensors, microarrays or membranes, and lubricious, wear-resistant, or anti-fouling coatings. Intellectual Merit: Understanding the location and distribution of functional groups installed in interfacial layers is a complex and challenging proposition because the nanoscale structure and its ability to be chemically transformed are intimately coupled: changes in the distribution of chemicaln tags in the layer and the degree-of-functionalization impact the structure and properties of the interfacial layer. To address this challenge, reactive polymer brushes based on poly(tert-butyl methacrylate) and poly(vinyl dimethylazlactone) will be studied. Both uncatalyzed and catalyzed reactions using sets of molecules ranging in size from oligomeric to polymeric will be investigated. The nanoscale structure of the modified brushes will be determined using neutron reflectivity, and a creative application of isotopic labeling in concert with contrast matching strategies will be used to determine the local density of functional groups installed in the brushes. To investigate how the display of chemical motifs affects the capacity of a layer to function, the nucleation and growth of calcite phases in modified polymer layers will be examined, providing a much-needed view of how calcium mineral phases form in synthetic polymer matrices. These activities will benefit from a new international collaboration that brings expertise in calcium mineralization in polymer matrices.Broader Impacts: Design rules that express how the nanoscale structure of polymer brushes is coupled to the arrangement, size and density of functional groups displayed in the layer will promote the efficient and optimal design of useful devices and constructs based interfacial polymer layers. For example, understanding the links between the display of functional motifs in polymer scaffolds and the growth of calcium mineral phases may advance the development of biomimetic constructs that help close the gap between synthetic and natural composite materials such as bone. The fundamental research can be classified as advanced interfacial materials research at and for interfaces, bio-medical advanced materials, and materials for possible long term sensor applications.In addition to promoting the training of graduate and undergraduate students and a postdoctoral scholar through engagement in research, collaborations with scientists at national laboratories and from Ecolé Polytechinque Fédérale de Lausanne (Switzerland) will enhance the professional growth and development of researchers involved, aided in part by planned exchange visits. Research activities undertaken in this program will be supplemented with outreach and mentoring activities that will bolster the recruitment, retention, and success of students from under-represented groups. Finally, results from the research activities will be communicated through publications and presentations by all participants involved in the program, and a symposium on reactive polymer interfaces will be organized for an upcoming national meeting.

摘要#1133320 Kilbey，S. Michael了解聚合物刷改性表面的原位化学转化这一先进材料研究的首要目标是了解通过化学反应转化表面附着的聚合物层（即所谓的聚合物刷）的能力如何受到表面密度、界面处链束缚的程度、游离溶液中存在的官能化剂的大小以及反应时间和条件等特性的影响。 虽然反应性聚合物刷受到广泛关注，但指导选择用于整合官能团的适当条件的设计规则仍然未开发并且在很大程度上未被探索。 为了解决这一知识空白，将原位产生和改性反应性聚合物刷，并研究化学改性界面层使矿物相生长成核的能力。 所有这些研究将增强功能性聚合物界面涂层的设计，从而为用于细胞生长的生物材料支架、传感器中的活性层、微阵列或膜以及润滑、耐磨或防污涂层的设计带来新的长期机会。 智力优势：理解安装在界面层中的官能团的位置和分布是一个复杂且具有挑战性的命题，因为纳米级结构及其化学转化的能力是紧密耦合的：层中化学标签分布的变化和官能化程度影响界面层的结构和性质。 为了应对这一挑战，将研究基于聚（甲基丙烯酸叔丁酯）和聚（乙烯基二甲基氮内酯）的反应性聚合物刷。 未催化和催化的反应，使用范围从低聚到聚合物的大小的分子集将进行研究。 纳米级结构的改性刷将确定使用中子反射率，并与对比度匹配策略一致的同位素标记的创造性应用将被用来确定安装在刷的官能团的局部密度。 为了研究化学图案的显示如何影响层功能的能力，将检查改性聚合物层中方解石相的成核和生长，提供急需的钙矿物相如何在合成聚合物基质中形成的观点。 这些活动将受益于一项新的国际合作，该合作带来了聚合物基质中钙矿化的专业知识。更广泛的影响：表达聚合物刷的纳米级结构如何与层中显示的官能团的排列、大小和密度相耦合的设计规则将促进基于界面聚合物层的有用设备和结构的高效和优化设计。 例如，了解聚合物支架中功能基序的显示与钙矿物质相的生长之间的联系，可能会促进仿生结构的发展，有助于缩小合成和天然复合材料（如骨）之间的差距。 基础研究可分为先进的界面材料研究和界面，生物医学先进材料，以及可能长期传感器应用的材料。除了通过参与研究促进研究生和本科生以及博士后学者的培养外，与国家实验室和洛桑联邦理工学院的科学家合作（瑞士）将促进有关研究人员的专业成长和发展，部分是通过计划的交流访问来帮助。 在该计划进行的研究活动将与推广和辅导活动，将加强招聘，保留和学生的成功从代表性不足的群体补充。 最后，研究活动的结果将通过参与该计划的所有参与者的出版物和演讲进行交流，并将为即将举行的全国会议组织一次关于反应性聚合物界面的研讨会。